Spx Ressurection Part 4 | The NITRO MOPED

[@Lord_Verminaard]

I think you are on the right track with the smaller carb. There is a chance that perhaps intake velocity is just dropping on it's face with the larger carb.

[@OlieWheeler]

I have to say, I thoroughly enjoy watching your videos. They are both entertaining, informative and experimentative. Very good job you're doing here sir!

[@2STROKESTUFFING]

Thanks man!

[@matejhujo5198]

Even better video than Last time. Like the symbolism with the dead end rail It rips my heart off when i see you strugle with Your own Engine. I think the smaller carb could help and What About to add Air filter ??

[@2STROKESTUFFING]

Thanks! I'll try a filter.

[@2STROKESTUFFING]

The pipe should work pretty good, at least it does in engmod simulations. Port timing 204ex, 132/130 trans. 5 transfers, main ex + auxiliaries, 145/88 intake, 14.5:1 compression

[@matejhujo5198]

2STROKE STUFFING it is clear Now that if he reduce the Air flow rpm rises there is too much Air but the Amount of fuel is limited

[@pathakajit]

Your videos keep getting better and better! The nitro moped story is now like an epic series where i wait for the next nail biting episode. Its very satisfying to watch you pull out a fine single malt in each video..

[@2STROKESTUFFING]

Thanks!

[@mealex303]

Thank you for the visual shout out!! Awesome

[@bramvelders6879]

The kind of insperation i get from just watching your videos is so much that i cant discribe it. Thanks man that you do this for us!!!

[@2STROKESTUFFING]

Thanks, means alot!

[@bramvelders6879]

2STROKE STUFFING. Did you see my imitation on the shifting west instagram? 😂😂😂

[@2STROKESTUFFING]

😂👍 I did!

[@geofham8332]

Hi, keep at it please. I am sure everyone is willing you to sort it out, and you WILL!!! Many thanks for all your videos as we are all learning from your efforts.

[@scott1brayden2]

I love this journey for power! Cant wait to see what squeezes that bit more, edge them extra rpms out !

[@Sahkopekka200]

The production value or just plain quality of your videos have taken a huge leap upwards! Looking and sounding great now!

[@2STROKESTUFFING]

Thanks!

[@Swarfman64]

Wow, your camera and editing are fantastic. The effort is appreciated!

[@2STROKESTUFFING]

Thanks man!

[@jurebizjak9275]

keep the good work☺😉 PS: your editts are getting better with every video

[@2STROKESTUFFING]

Thanks!

[@metrashit]

Great video! I really like the stuff you do, kinda new gen engine builders. Back to basics, trial and error. Really educational.

[@2STROKESTUFFING]

Thanks!

[@AuMechanic]

Worth a try on the stinger, although I would have done a test run without the muffler to be sure its clear. I think you need to retrace steps backwards out of the forest to ground you know it was working. As a mechanic its part of almost every diagnosis, need to resist the temptation to try more then one thing between tests. It can take a long time doing it that way but you wont loose your way if you stick to the method, likewise in race tuning, single steps forward and test each time. If you back track to the old carb on petrol to begin with you know that revs fine. If it does not rev then something else has failed in the mean time and you can step sideways to that and fix it. If it does rev then go forward one step at a time, try old carb on Nitro, if good then try it both bigger carb on Nitro. It's the longer way around faults but its the safer way home.

[@2STROKESTUFFING]

Good advice, you're absolutely right. My approach can be a bit chaotic...

[@2STROKESTUFFING]

Good advice, you're absolutely right. My approach can be a bit chaotic...

[@AuMechanic]

If you work back to the "last known good" position it then becomes evident that a fault has occurred that is not related to the mods you made if it still doesn't rev.. Then it becomes a basic fault finding exercise as if nothing was done to the engine and you were unlucky something failed during the changes. If you do not go back to last known good then there really is no way to know if its a failure of something or a result of one of the modifications. Going through a list of possibilities in that case can end in frustration because each time you try something and pin a fair bit of hope it will fix the problem and when it doesn't you are still none the wiser. Maybe you make a rubber sleeve or the like to fit the old carb on the new manifold to test it so you don't have to commit to a new manifold you might not end up using. Sometimes you can be better off assuming something you are about to try is not going to work so you don't invest too much hope and effort (cost) in to test for that condition.

[@DeBoswachter]

Seriously impressive video! And great work on the two stroke! Keeps me motivated to work on mine in these cold days.

[@2STROKESTUFFING]

Thanks!

[@piotrwysocki3114]

Dude! Your videos are awesome! You really deserve more subs. I really liked that "artistic" scenes. You really helped me with my moped, I hope you will make this beast work! Huge props from me.

[@2STROKESTUFFING]

Thanks!

[@ludditeneaderthal]

I'm gonna say the muffler. Last time we established 9 liters per second intake flow at 11k rpm. But the volume exiting is greater because of expansion. Even greater than your gas engine, because you run a far greater mass of liquid in the mix. Mufflers work by slowing the exhaust stream. Greater stinger cross section area gave modest improvement, but below the flow increase potential such an increase would be expected to provide (a few percent greater for a right around 30 percent increase in cross sectional area). We know your expansion chamber did it's job to near 14k rpm before, we established exotic intake forces are a non issue last week, and your fingers established intake aperture fiddling returns little this week. That leaves us continued flow restriction of the greater exhaust volume. The glaringly obvious example of that is the component designed to slow that flow, the muffler. Next logical step would seem to be removing it, and possibly exhaust wrap to maintain temperature of the stream (more retained latent energy). Sounds almost too simple to work, yet seems like the easiest change possible, and is pretty much supported by observed results. Until you hit the exhaust cycle, pumping volume hasn't really changed much from your previously higher revving example, with changes seemingly suited to higher flow. BTW, I noticed you advanced the rum intake timing to a couple dozen steps before the garage door, which couldn't have hurt, lol! Keep at the nitro nightmare, it will come!

[@thatguycalledart6270]

As I said on my last comment on the last video, I had the SAME issue on my RZ50 2 stroke 50cc and it was due to a damaged crank causing loss of compression. Sounds weird loads of Yamaha “specialists” said spark, fuel etc but it WAS The crank

[@turtlemann14]

you can see in the carb that it stops pulling the air in as fast at wot. (fuel stream gets wider) if the carb doesn't do it then id have to say porting assuming everything else is back where it should be. if the smaller carb does work, i'd try a spacer (more intake volume) for the larger carb.

[@terzepterblue285]

Loving the production quality, keep up the good work.

[@2STROKESTUFFING]

Thanks!

[@DougBinderCozy4]

I forget what size carb you have on the bike now but there is certainly something to be said for testing the 24mm carb. Considering that the velocity of the air moving through the carb is a function of the area, and that the area is the square of the diameter, even a 28mm carb will have 36% less velocity than the 24mm.

[@brkofobija]

Because of the excess mixture, the exhaust gases cooled, the sound speed decreased and the exhaust system had to be shortened. Try isolating the exhaust bar with a tape to achieve a resonant shortening effect (higher rpm). Changes work 1 per 1 because you will sweat otherwise! Cheers!

[@jimmyhedlund7997]

My new favourite channel! Keep up the good work!

[@2STROKESTUFFING]

Thanks!

[@boriskozjan]

huge improvement in video production, good luck with the engine...

[@2STROKESTUFFING]

Thanks!

[@Djokkinss]

your video production quality is excellent!

[@2STROKESTUFFING]

Thanks!

[@freakonaleash235]

Great song, great video, great editing. Love the videos! Keep it up!

[@2STROKESTUFFING]

Thanks!

[@404MissingLink]

You should try using a long velocity stack to help increase the air velocity and reduce turbulence. Often open large carbs don’t run right because the air coming in is way too turbulent

[@CodyStrijbosch]

Might be the expansion chamber of your exhaust. A friend of mine had a similar problem. He had to buy a bigger exhaust so the gasses could flow better.

[@DevinderAthwal306]

I've had an issue sort of similar in a rotary valve kart engine I bought. The person I bought it off had the valve in the wrong so the timing was messed up. It was strong low down, pulled really well but then hit a wall up top. Another thing on kart engines, when the low jet was too rich the kart would it a wall at 14k rpm, leaned the low jet off and it would rev through nicely.

[@2STROKESTUFFING]

Thanks, I'll have to check the valve timing again.

[@Barrebasje]

Beautifull editing work! Hate to see you struggle with the spx but you'll get there i believe.

[@2STROKESTUFFING]

Thanks man!

[@chucksterock]

I also have to complement you on the major step up video creation. Really impressed. Carburetion does seem to be the only answer left. I don't think the small stinger would restrict it, it just would hold the heat and force a richer mixture to avoid melting it down. Though I have seen some funny things happen due to ignition curves. Honda dirt bikes have that built in rapid advance to avoid over-rev when in the air, but when loaded on the ground like in a kart will stick the motor hard. I have been racking my brain trying to figure this out, but no good ideas from me.

[@2STROKESTUFFING]

Thanks! We'll get there!

[@BennHerr]

Had to deal with a shifter kart engine (CR125) that would not rev over 10.5k when all the other engines just like it would go 13k - 14k all day. Turns out a new spark plug had been installed that was a resistor type and that along with the resistor plug wire cap was the culprit. Switched back to the old plug and everything was fine. Don't know if that kind of thing is happening for you. Another thing to check would be the rotary valve timing. It's probably correct but it wouldn't hurt to make sure.

[@ngneer999]

Wow. I've been thinking about starting a youtube channel about basic electronics but after watching this video I can see I need to go to film school first .

[@2STROKESTUFFING]

Thanks! Do it, you'll pick up the filming part in no time!

[@ekner]

Just spitballing here... Does the inlet tract have its own resonant frequency? Changing the inlet size with your fingers surely would change some tuning, which to me hints to the possibility you might be reaching some weird flow state at the brick wall rpm. Maybe move the carb out a bit, or add a length of pipe at the filter end, see if that changes anything? I'm sorry the stinger didn't work out, I really had my hopes up for that one.

[@jons6125]

Great seeing the carb side shot and videography in general 👍

[@paansukarjo90]

try for a hotter plug, probably it will help since you said the head temp drop a lot.

[@geop6132]

Great work. Love your videos and your passion on 2strokes. I believe your problem is the ignition. I hear the engine missfiring. Did you raise the compression ratio or is it the same before the cylinder mods you made. If you did raise the compression I think there is not much spark energy that leads to missmfires at these revs. Good luck pal.

[@2STROKESTUFFING]

Thanks! You might be right, I too think it sounds like misfiring, and ignition voltage becomes very high at "the wall" probably because it's struggling to get a spark going.

[@geop6132]

Try to reduce the plug gap only to see if it revs more. If it revs, you probably need better coil. Keep up the good work

[@2STROKESTUFFING]

👍

[@MikeyAntonakakis]

I am pretty confident the carb will help, assuming it doesn't foam all over the place :) Maybe it will be a good excuse to use the clear float bowl again. No matter what, you will figure it out! Just keep the methodical approach!

[@Havl1s]

Or you can test it if it is lean by spraying the petrol to the carb intake. Or use starting spray at the moment it hit the rev barier. This is the way you rich the mixture. If you rev more it is lean.

[@trapsdrummer890]

OK, I get it, you're not a mechanic, you are an artist! Subscribed to your channel and cancelled Netflix. Love what you do. The music is nice too.

[@2STROKESTUFFING]

Thanks man!

[@neekeri2934]

Hope you get it going with the 24mm carb :)

[@Havl1s]

Have you checked the squish velocity? If there is not enough fast turbulence in mixture, then burning speed is slow and you can not rev. Burning is slower than the pisto progress to down. On the dyno it look like rev restrictor and torque vent immetiate to zero. Just a hint.

[@2STROKESTUFFING]

Yep. Can't remember exact numbers but it's good.

[@DerKrawallkeks]

Woow, this is entertainment with class, on the highest level. Enjoyed it a lot! I'm almost glad the problem isn't solved just yet (-;

[@2STROKESTUFFING]

Thanks man!

[@Hollaendaren]

Come to think of it, I've also had a carb that I just could not get to work on my engine. It would not rev and just sounded like it was 4stroking. I tried getting it to work for days, jetted all over the place, changed ignition, everything, it just wouldn't run clean. Finally tried putting my old carb back on and everything worked again instantly. I still haven't found out what the actual issue was back then, but the theory we had back then was that the carb needed an airbox in order to work as intended. Hoping that's it, I know how mysteries like this can drive one nuts... Until you figure it out, then you're happy because you learned something :)

[@2STROKESTUFFING]

Crossing fingers!

[@lobotomyy]

Same with me, thise fako oko carbs can sometimea work sometimes not. I had also a fake one and it run all the time untile it didnt. Cleaned it and rejetted still didnt work. Then bought a different carb and revved again. If his bike still doesnt rev then i think that the exhaust temperature is too low

[@AuMechanic]

Yes carbs can produce a number of conditions from the metering circuits to the size ratios and they can also appear to be failing when it is something else in the engine. Many a carb has been rebuilt in the hope it would fix a fault that turns out to be not related to the carby. Going back to the known good carb can quickly sort out which is the case.

[@silvesternatonji7404]

Great video I still think its either air leak or to much compresion. I had similiar problem on my moped runing on gas but i rebuild it and changed the head and problem disapired.

[@jianoconnor8414]

Straightening the air may help a bit. An intake hose, PLUS I suggets a K&N cotton filter. Foam may straighten better, but I found foam restrictive. K&N flows more. According to K&N themselves; their filter increases intake flow compared to no filter at all. (Your set-up). I believe this is due to turbulence. Think of a horde of people trying to enter a stadium. compared to organised lines of people entering. The latter will allow more to enter faster. :) hope this helps :)

[@2STROKESTUFFING]

Thanks for the tips! I have to experiment!

[@marioraja4229]

Wow... i thought i was watching a movie :D, your video production level is really good!

[@2STROKESTUFFING]

Thanks man!

[@moskavado]

You need a big expansion chamber with that big carb. And then experiment with different sized stingers imo. And tjek ignition timing.

[@andy198712]

When you had the side on shot, the engine seemed to be at full throttle when the slide was 3/4 of the way up, hopefully the smaller carb helps!? Good luck

[@giovanibalduino]

I had the same problem with an engine 200cc 2t using methanol in Brazil. with Castor oil in 16% when cold and using cold plug it has the same limit rotation. putting a hot plug the problem disappears but during the race the plug broke the solution was change to oil synthetic using 5%. Rc fuel normaly have a blend oil castor/synthetic

[@2STROKESTUFFING]

Interesting!

[@InIMoeK]

I had these kind of issues on my competition racing scooter. In my case it was the vibration causing air bubbles in the carb. I had it fixed with rebalancing the whole rotating assembly and just for caution used a softer inlet adapter. Not sure if something like this can be the case with the fuel you are using..

[@hugh381]

Alex you could try cutting the mix back a bit with some petrol using acetone as a mixer this way it would help maintain some heat and possibly stop the breakdown in combustion at higher rpm, (species5022) is on the right lines with the slower burn. great edit buy the way.

[@alltheboost5363]

I wonder if it has something to do with the heat range of the spark plug.... especially with the exhaust temp in cylinder head temps dropping at the wall.

[@upsidedowndog1256]

Beautiful video. You will figure out moped soon.

[@2STROKESTUFFING]

Thanks!

[@gcardpt]

so.... Congratulations for the video edition. is top! test the power spark on a dremel or on the router. sounds a bit of eletrical problem (almost same rpm ever).

[@2STROKESTUFFING]

Thanks! It does!

[@hopsgarage5513]

Great into. Keep up the good work sir.

[@2STROKESTUFFING]

Thanks!

[@MrNotStock]

I love your editing

[@2STROKESTUFFING]

Thanks!

[@nthorpey]

Have you got access to an oscilloscope? Try looking at the ignition pickup to see if this can respond in time to make/break the signal etc. Is there any inducted signals being made by wiring to induce a rev limit ?

[@stevesolo16]

I can only speak on gas motors. To really know your tune, pull the head and read the top of the piston. Look at the color delineation on the plug electrode. When you have achieved a perfect burn keep notes as to how the carb was tuned and what the adjusted altitude of the air was when everything came together. These notes, and the adjusted altitude algorithm will give you the advantage during a California Timing Assoc. speed run. To set records, your tune has to be perfect coming off the trailer! Note, to make the perfect pipe you need egt.

[@2STROKESTUFFING]

Thanks for the tips!

[@stevesolo16]

@@2STROKESTUFFING I have never seen a more motivated builder! I hope you accomplish all you have set out to do.

[@tomm9176]

Could there be any blowby. If you could measure air in velocity you might find a dead spot. A Reed valve would greatly reduce or stop the dead spot.

[@davespooney8472]

I'm out of ideas re your issue - so good luck! Loved the vid

[@2STROKESTUFFING]

Thanks, we'll get there!

[@skidoorenegade77]

Nydeli filming. Du gjør en sinnsykt bra jobb me redigering å filming. Meget bra. Må bare takke for en GO Kanal. En av di bedre æ følger. Æ prøve og vri hode om hva det kan være. Men vanskelig uten å teste. Trur vi alle har vært dær😊

[@2STROKESTUFFING]

Takker!

[@integral32gb]

... and the saga continues.. One man struggles alone against the very forces of nature. The laws of physics counter his every move, épée to parry then riposte, battle continues unabated, neither side delivering the decisive coup de grâce. Hehehee, what an epic riddle in the snow or garage. Running out of ideas here Alex, however if its to do with exhaust cockup or fuelling spanner in the works then I'm a yellow teapot. By the numbers: 1. Change your Li-po back to a lead acid battery 2. Not sure I'm a big fan of the Hall effect sensor Powerspark has supplied. Doesn't look automotive quality, hope its not vibrating on its mount, did they specify an air gap for the sensor/magnet? Not sure that the 3 wire cable is up to the job either, I can't tell if the cable has shielding or even if the 3 wires are twisted together. I say this because of the electromagnetic discharge you get from the coil magnetic field collapsing and HT emissions from the HT wire/cap/plug. These can seriously f**k with ignitions and EFI if not shielded in some way. Which brings me to..... 3. Check on the ESE thread and look for problems Wobbly was having with the Ignitech and stray EMP. Search 'Ignitech resistor'. Wob solved the problem by using both a resistor plug and cap. Good luck, your gonna need it. PS. Might wanna actually set a rpm limit, say 20krpm, never know pigs might fly.

[@2STROKESTUFFING]

Thanks for the input! I'm hooking up the old ignition unit and battery, at least I know it worked to 18k rpm+ before. I agree about the hall unit, it's basically just a small pcb.

[@integral32gb]

No worries, its going to be somethng very simple/easy fix or impossible to get to the bottom of. Thats the nature of these things. I have to agree with what AuMechanic said above, need to concentrate on 1 sphere of operation until its avenue is exhausted and not crossing over here and there. Just something learnt over 30+ years of farting about with engines. If your going back to old ignition, do a continuity test on the Hall sensors while applying a bit of bending force to the sensor with your finger, just to check if the pcb pins haven't fractured with vibration and are acting like an on/off switch once the engine gets into a vibration mode. Also check the integrality of all connectors, had it before where a bad wire/connector has kicked the guts of a perfectly running engine prior to tear down/rebuild. As i said before the problem has to be ignition, the inability of the engine to rev without load is the give away and its consistant.

[@brkofobija]

Perhaps the opening angle of the rotating disk is too large, also check the suction channel surface to be equal to or slightly larger than the 32 mm carburetor surface.

[@sturgis87]

4:20 Wes Anderson stuff right there :D

[@TheWanke]

I really like your videos! The editing is great. Even if you would not have spoken a word i would understand your struggle👍 now fix your engine and i make popcorn😊

[@2STROKESTUFFING]

Thanks!

[@anthonydiridoni7347]

Brilliant, enjoy your videos a lot. Yep, smaller carb. Higher intake velocity. You will make that thing sing soon.

[@2STROKESTUFFING]

Thanks!

[@lobotomyy]

*what i try while jetting is running the bike on full throttle and then turnig fuel valve off so it cuts fuel and either will rev up b4 dying or run even worse*

[@obonk69]

i had an fa-50 do the same thing and it turned out closing the gap down on the plug fixed it since the coil was shorting to the frame due to a bad plug wire. im sure you tried this, just giving my 2 cents!

[@2STROKESTUFFING]

Could be it. Secondary voltage is very high when it's hitting the wall, could indicate a difficult to ignite mixture situation.

[@samuroma700]

Did you try to put the largest max circuit on that carburator? Maybe you just have to close a little the air circuit and gain fuel circuit. What size is that carburator? I'm not an expert, hope this can be helpful. Great works on your garage, let's keep 2 strokes alive and make them better

[@johnmundt2017]

hey do you have a EGT pyrometer so you can look at real world temp for jetting it will help on fuel curve... the carb does seem large but usually too large effects low speed far more then high speed. but thinking of it to large will typically make it lean low speed so if low speed seem ok maybe the fuel curve goes way rich as rpm goes higher it does sound like it 4 stroking and all 2 strokes will hit a wall when that happens.EGT might help you see this

[@shug831]

Love it! Like the cello.

[@2STROKESTUFFING]

Thanks!

[@explosionsgonewild3593]

try playing with the spark plug out of the motor. rev the cdi to 16000 rpm with the sparkplug out and do a slomo to see if its cutting spark or even misfiring with so many signals per second. also after the motor is hot it shouldn't have any loading up issues. if it did it would normaly foul a spark plug.

[@derknobit2616]

Maybe with the carb the size it is maybe it can't pull the massive amount of fuel in. If I remember correctly Nitro has oxygen it so choking the carb may not have as much as same effect as with gas

[@ngneer999]

I think it's the inductive pickup. If you can't test this with some sort of electronic equipment I will suggest you try something which is a terrible idea but that's what I do. Remove the cylinder, piston, connecting rod and re-assemble the engine. Make sure main bearings are lubricated well. Attach a small pulley to the crankshaft and a motor or dremel drill to a larger pulley. Using an o-ring for a belt, spin the crankshaft up over your 11K RPM limit and see if the spark plug still makes spark. Yes I'm insane.

[@LCOOTS]

good music! excellent editing keep it up

[@2STROKESTUFFING]

Thanks!

[@lemax5881]

Try putting a air filter on the carb it will restrict the airflow when it’s reved

[@gsx44]

Maybe u should try with an airbox or something similar to make air flow straight less swirler and get better carburation

[@arthurlunn9430]

Could it be the c.v. clutch dragging it back out of powerband as it seems the motor has a fair bit of resistance to overcome as the cv clutch/gearing opens and shuts. The motor also moves and encounters restance. Stab in dark really but you've tried everything else. Maybe a normal gearbox wouldn't do this. Great show.

[@2STROKESTUFFING]

Unlikely - happens with the drive chain off too...

[@species5022]

isnt it like with alcohol, that it burns slower so you need even more advance in the ignition?

[@2STROKESTUFFING]

It is, but not that slow - remember I had it running good on this fuel before, and peak power only shifted slightly in the rpm range.

[@johncollinsgrove1750]

Around the time you started with the nitro I thought you found out something about timing may not be taking until you went back and selected it again. Also do you think that their may be some old stale fuel build up inside engine? Have you done compresssion test. Other than that keep going back to the way it used to be. Good luck. Want to hear some victory music the next time you make a video.

[@funkyhobbit]

I am no expert, but years ago i raced glow fuel disc induction model boats. 15cc , 7hp, 19-22k rpm.. When running on 16% nitro fuel the pipe length was not super critical when tuning for a specific rpm rating.. Give or take 1cm long or short.. But when running on 25% plus nitro methane the pipe length was super critical, because of the cooling properties of the extra nitro methane.. We had telescopic headers sealed with 19mm id silicone hose.. which allowed easy change of the pipe length.. A Telescopic header to pipe connection may help your situation. Best of luck :)

[@species5022]

The only other thing i can think of is maybe the timing is off on the intake rotor. That it is still slightly open when the piston passes tdc.

[@MetroidChild]

The nitro compensates that quite a bit from pure alcohols

[@Toddemone]

Have you tryed to bend the exhaust up over the variator? That give you more backpressure

[@Sketch1994]

It could be even the balance factor! I've heard of people who tried different balance factors and weights and came up to a "wall"...

[@2STROKESTUFFING]

Could be, but it reved happily past 18k with the same factor before.

[@timakkerman1294]

It could be your gas needle that is worn out so the gas starts doing a wierd swirl so it wont have enough gas

[@georgegrimm1837]

Top Fuel dragster nitro engines require more joules of spark. Could you be not getting enough dwell on coil. Or how about going to a glow plug like model airplanes to eliminate spark as a variable.

[@kullezkuppandere7887]

Awesome editing dude (y)

[@2STROKESTUFFING]

Thanks!

[@ngneer999]

Do you have a different , more basic ignition system that you could try? I see no way that a totally unloaded 2 stroke engine has some mysterious rev limit. An oscilloscope with an inductive pickup would be cool to see but fairly complex to set up.

[@KevinTodd]

2" power band between front and back cones that is how we get 18+ grand out of our zenoah's

[@EJProMods]

Any changes to head design in compare to previous? Especially to squish band? May be problem with spark plug wetting? I think rc fuel droplet size a lot bigger and volume to. May be tighter gap and hotter plug could help? Another thing may be rotary valve problem? Can You try reeds?

[@2STROKESTUFFING]

Same head, I'll experiment with the gap.

[@nikosliras8102]

Try playing with the intake length using different size pipes on the carb ... Or does that not make much of a difference in 2 strokes??

[@kolten808]

Maybe bore x stroke not matching minarelli pipe, maybe too short header pipe or angles are wrong. I wish I had a welder.

[@shedbuiltable]

lengthen the inlet tract see if it makes a differance

[@jandeman198]

great music, lovely video work, nice concepts! it's inspiring. can't remember how i stumbled upon this channel, but i have been binge watching all of it :) (and jaydghxsxhs stuff :) )...as a relatively experienced 4stroke bike rider and diy mechanic i'm learning so much! and yes, your recent videos are getting better every time ...now time for some islay malt :) Oh, and if you haven't seen this already, check out project binky on KZbin (2 UK blokes making a Celica GT four - mini) . Best mechanic/humor/fabrication series on the planet :)

[@jandeman198]

and sorry, haven't got a clue what might be wrong, but to my very untrained ears, it sounds like ignition timing...i can't imagine that fueling/exhaust has such a 'wall' effect...it would be more gradual i would think?

[@2STROKESTUFFING]

Thanks man! Love project binky!

[@e-z.g4188]

I think you need more fuel will it run on petrol or try spraying some easy start in the inlet to see if the revs change

[@2WheelWill]

Great work! Great editing 😁

[@2STROKESTUFFING]

Thanks!

[@garystat]

Fabulous video very enjoyable. I guess perseverance is the only miracle.

[@2STROKESTUFFING]

Thanks!

[@michellatour150]

try a velocity stack on the carburetor's inlet

[@hulkyfps]

I don't know, but I feel it could be the plug.. It's gonna be one of those things that will make you slap yourself silly when finding out😂

[@YuSo_]

I might be talking rubbish here but could it be an engine balance issue creating a mechanical maximum rpm. I remember the videos you did balancing the crank and pins, but have you considered the rotary valves balance? I know it is very light but, at higher rpm the energy required to keep the rotary valve on the shaft as it tries to pull outwards away from the crank because it is unbalanced could possibly reduce power or mechanically restrict the engine. Apologies if this is rubbish, just trying to think outside the box. Great work, love your videos!

[@2STROKESTUFFING]

Thanks! Seems to be balanced ok, I know how bad it vibrates when it's not.

[@GGXjimmy]

it sounds like you are describing a limp mode.. rev cut and rich. i know its carbed but it is sounding like an ecu problem. is there any other ecu you can try? to me if it was anything else then changing the load would cause the problem to come at a differnt rpm. it really sounds great on its pick up then just simply hits a wall....rev cut>!>! Could your pick up be flexing or the magnet not strong enough for the high RPM? maybe the ecu or coil cant handle the current or isnt giving enough. spark gaps? spark temp range? power supply? can you measure voltage at peak rpm? good luck. i know you will get there! lagavulin 16 is one of my favourites, try Ardbeg if you like a bit of peat :)

[@elbacanreal]

Great vid, I really like the music. Id love to know what it is and where you get it. Do you have Any like links?

[@dunworx3758]

great videos man,always looking forward to ur next vid.have you done a crank pressure test ?

[@2STROKESTUFFING]

Thanks! I haven't yet.

[@pichi5733]

Maybe check compression, could be that the piston or cylinder is damaged.