I Bought a 1969 Honda CT90... Now With Piranha 140cc Engine

[@donellmuniz590]

Mine has a giant rear sprocket that actually fits OVER the original sprocket! I never counted, but it must have 60 teeth. So it would probably top out at 20mph, lol. But I'm 270 lbs, so I need the torque. UPDATE: Down to 240 lbs!

[@michaelcollins3455]

Your bike must be earlier 60s. The big sprocket is for low speed, off road. The smaller one is for highest mph. Later, Honda built hi/low into the Trans. Before that, you swapped the rear sprocket and add or take off a short piece of chain.

[@donellmuniz590]

@@michaelcollins3455 Yes, mine is a '64, a pushrod motor and that goofy front suspension. Unfortunately, the engine got water in it, and it's badly seized. I'm hoping my friend, a bike whisperer (lol), can get it unstuck. I dont care if it smokes, lol.

[@spikeman68]

i grew up in the 70s my dad was big on hunting in fishing,great memories of hanging on to the old man while he was laughing his ass of going thru rivers and trails....great little bike,my rupp mini bike would give it a run on the straight aways!!! lol

[@danielkneale2237]

I have a bone stock 1970 CT90. Stock engine, gearing, carburetor, exhaust, even the tires are original. Is been well used and the engine hasn't been rebuilt. Mine will just barely do 50 mph and I'm around 200 lbs. Something isn't right if yours isn't going faster than 35 mph.

[@NickMakesBreaksStuff]

You're right, something is wrong. Its was a very tired (and now broken) original engine.

[@Hodado]

I think he meant that your Pirahna has something wrong if 35 is top speed

[@SamSamuylik]

I think your speedo cable is broken, so its slipping somewhere. Consider changing the front sprocket on the engine for a larger one

[@awptickes]

Nice build. It looks good, unlike a lot of the engine swap builds many people do.

[@eightv1982]

just saw this video. the 4v 190cc gets all the clicks, but the $$$$ is insane. the 140cc is the way to go, you can buy 3 of them for the cost of a 190 engine.

[@bavarianbanshee]

Man, it even still sounds like a 90! Very impressive! This seems like a really awesome swap, and just what my '74 needs. If you could post direct links to the engine and each of the parts you used, you'd be my hero! Btw, at least to my eye, that speedometer seems very, very off. You might want to check it, the cable, and the front hub.

[@Shawn-ho6de]

I had a 1969 honda trail 90 as a kid....so much fun!

[@tauncfester3022]

Should really add an oil cooler. You have the pipe the shunts the oil feed up from the crankcase, just needs the flex pipes and the cooler, don't cheap out on this. The 140 makes a lot of heat, more than the quart of oil and small engine's bottom size can shed, if you're going to do some distance at speed on the highway.

[@kernered15]

Nice, good to see the 140 put into a later model CT. I have the 140cc manual on a 1965 CT200 and it runs great and bolts right up with only minor grinding. I suspect that muffler is really restrictive. I can get mine to about 55 MPH pretty easily with a 17t front sprocket and the power is solid through the powerband. Looking forward to future videos.

[@NickMakesBreaksStuff]

I agree, with a less restrictive exhaust and maybe a larger carburetor (currently a 22mm mikuni clone) it should be able to reach at least 60mph

[@donellmuniz590]

CT200? I've never heard of that one. Does it look like a 90?

[@nielsdebakker3283]

@@donellmuniz590 The ct200 is a pushrod 90cc cub.

[@nicoanon]

i know this is an older video but a parts list would be nice

[@fixento]

What do you mean ugly, it need TLC, we rebuilt a yellow 1969 ct90 trail K1 with 1200 miles on it. Top speed with the original 90cc 7 HP is 50 miles per hour on the flat with an adult on it. In addition our gear box has a low gear setting for off road. I suggest you also rebuild the front shocks.

[@mattyamaha27]

I am about to do the same thing. In Norton, Ohio. See you at vintage days!

[@deborahchesser7375]

I hope it doesn’t get canceled again

[@pujabelgian]

Figuring out the footpegs is my problem. I've got the atc125.. it bolts in nicely but the ct90 fp bar will definitely not fit.

[@donellmuniz590]

I need to do this on my '64 Trail 90! The engine (pushrods in 64 and 65!) is stuck and rusted beyond repair, and the electrical system is spaghetti. I dont have a headlight, so I dont care about that (until I get lost in the woods at dusk).

[@1439of2000]

FYI you would have a ct200

[@yourselfdotcomlol]

The hi lo gearbox is a gem in the originals

[@joshrogan9854]

Nice conversion.. I have a C90 which needs a transplant. PS Rev matching will make your downshifting smoother lol

[@broadwayFan28]

Setting the idle up a bit will smooth the downshifts also. It's a fine line, too much idle and it's hard shifting.

[@tauncfester3022]

If the momentary clutch disengagement of the semi auto is adjusted carefully there should be no need to RPM match, this isn't like a non syncro transmission like on some early 1950's truck.

[@jj8716]

good for you. i hope you have fun.

[@MW-vj1cw]

Your speedometer is either toast or the cable...Your going way faster then indicated...Sounds like high gears... so yeah speedometer or cable...

[@pujabelgian]

These are cult bikes! I bought a ct90 and spent the first 2 weeks learning all about it. I'm now officially in the cult. lol 😊

[@edwardbernal4422]

I have been in the cult since I was 5.

[@philthompson5868]

Did you change the sprockets?

[@SugoiBoi]

I have a 69 CT90 and just got a piranha 140 semi. Did you have to drill the top engine mount for it to work with the original engine mount bolt? How did you get the DrATV mount to work? Mine doesnt seem to line up on one side... On later videos I see you have the factory skid plate on. Did you have to modify it in any way? Are those pitbike pegs the straight ones or the upsweep ones they sell? Sorry for all the questions, just trying to figure everything out before i start my swap!

[@NickMakesBreaksStuff]

I did have to drill the upper mount, as described on DrATV. I also ran into an issue with one side of the bottom mount bracket, so i'm only using the side that fits, and added a spacer in place of the side that doesn't line up. I needed to cut a small notch out of the skid plate to clear the side stand. The pegs I'm using are the generic straight pit bike pegs. Let me know if you have any other questions!

[@SugoiBoi]

@@NickMakesBreaksStuff thank you for the info! How hard was it to drill the top mount? Thats the part im afraid of messing up. How did you mount everything? (Example: lower Mount then pegs then skidplate? )

[@anglegrinder4630]

What do you think is better engine an original honda 90cc or these 140 lifans and pirannas?

[@NickMakesBreaksStuff]

Depends on what you mean by better. The 140 is obviously more powerful and has lots of cheap parts very readily available. I haven’t had any reliability problems with mine, and the bike is way more fun to ride with the 140. I do prefer the original look of the 90 engine though.

[@JohnTrottoCreations]

How did you mount the original CT90 exhaust to the Piranha 140? I am in the middle of this swap, and the 140 has a totally different mounting surface and design to the original 90 motor. The Piranha is a 32mm hole. The 90 is more of a recess for the lip of the 90 exhaust to sit into. My guess, is that you actually have a 110 exhaust on there, not a 90. They are different diameter mounting faces.

[@NickMakesBreaksStuff]

I bought a cheap exhaust off of Amazon (advertised as being for a Ct70), chopped of the header section, and welded it to my original CT90 exhaust

[@JohnTrottoCreations]

@@NickMakesBreaksStuff okay yeah that makes sense The CT 70 was a 31.5 mm diameter so that would have been close enough for you to get it to work. Thanks for the info.

[@philthompson5868]

Just got a 69 ct90 with the 140 in it. First gear is too jumpy taking off, so I use 2nd gear. Engine revs out at 38 mph. How many tooth rear sprocket would you suggest to get it up to around 50 mph?

[@elijahevo6859]

17-35

[@craigmonteforte1478]

Very Cool I have my fathers 1964 Honda S90 that he put into Storage indoors in 1965 and the bike is complete and all original i was hoping to use OEM parts to convert it to a semi Automatic Clutch because i have a Disability in my left hand that makes operating a Lever Clutch very difficult my plans are to do a semi restoration to make the bike a Rider but because of the history i would like to use OEM and Period Correct parts unfortunately i found out that the Honda Semi Auto Clutch will not fit inside my case like a Monkey bike uses ? my Engine was refreshed with new Rings ,gaskets and other parts not too many years ago by a Uncle who was a retired Mechanic and a Engineer who tore it down because the kick starter had sheared off part of the Mechanism because kids used to play on the Motorcycle when it was in Storage so i don’t beleive i will need to do a Motor Swap which is a nice cost savings Unfortunately the last few years parts for these motors have been going up because of World demand and the Internet although the positive is there are a lot of parts available and in some cases the Clone Engine parts are a good fit as well maybe not the quality of a Honda part but can work in a pinch

[@NickMakesBreaksStuff]

I would think the easiest thing to do would be to find a used CT90 engine to put into your S90 frame. That would keep it all vintage Honda, but provide you with the automatic clutch. The s90 engine has a bit more power, but if you care you might be able to swap the S90 top end onto the CT90 crankcase.

[@justinariasdrummer]

Do the original bash bars not fit with the 140?

[@NickMakesBreaksStuff]

They do fit, you may need to add a couple thick washers or spacers to where the bash plate mounts to the engine in order to clear the pit bike style foot pegs / side stand

[@datnotme9921]

Did you have to weld in the bracket from dratv to help hold the engine or is it bolt on. I've a '73 Honda CT90 Mars Orange. Sounds nice! 👍👀

[@NickMakesBreaksStuff]

No welding, its bolt on. I had to do some finangling to make it fit though.

[@michaeljones0007]

The Dr also sells a steel plate with mounting holes to use stock foot pegs. Goes for 19.99 on the site.

[@rolf9280]

@@michaeljones0007 then Dr? Could you send me info if they are a parts supplier please? Thanks, Rolf

[@bisdak9261]

How do you start this? Choke up or down? Gas lever up or down (On or Reserve position?)

[@NickMakesBreaksStuff]

I start it with the fuel tap in the "on" position, and choke up if its cold. If I've already been riding it no choke is needed.

[@riridingeverywhere6555]

I just finished doing the same swap on my CT 90. I used a 140 with a manual clutch. Did you have to modify your exhaust pipe? I had to change the end on mine and the angle. I also had issues with the crank case vent and had to grind on the frame . Did you have to do that?

[@NickMakesBreaksStuff]

I don't recall needing to grind the frame at all. I did need to modify the exhaust. I cut head pipe off of a CT70 exhaust and welded it onto my CT90 silencer.

[@riridingeverywhere6555]

Interesting they must have ran the crank vent differently on the auto clutch version. That's for the response.

[@gmoney4797]

Where did you get the new ignition switch?

[@deepbludude4697]

I just got a 64 CT200 trail 90 for free.. i wanna up power it im curious if the Piranha will flt in the same?

[@NickMakesBreaksStuff]

Nice! What color is it? I believe there are differences between how the CT200 and CT90 engines mount, but I'm not sure if it would make it harder or easier. I'm sure its doable though.

[@deepbludude4697]

@@NickMakesBreaksStuff Im near on too color blind but my Artist GF said its Orange its in remarkably good shape especially for a MC thats been in FL. I been searching for a carb for it but crazy expensive id rather have a china motor in it as it will be used regularly. I have swapped predator motors into several things including a XR200 and I have an IT175 rolling chassis that I already have a motor built for it. Im in the process of moving though so have little time for a milion projects.

[@donellmuniz590]

Wait, it's a Trail 90 but it's called a CT200? I have a '64 Trail 90 with no plastic and no papers. So mine is called a CT200? Why?

[@NickMakesBreaksStuff]

@@donellmuniz590 CT200 is before they started naming bikes by engine size. The CT200 was made from 64-66 (66 waa also the first year of the CT90) and the main difference is that the CT200 has an iron head pushrod engine, while all CT90s from '66 on have an aluminum head OHC engine.

[@donellmuniz590]

@@NickMakesBreaksStuff Thanks for clearing that up. My '64 does have an iron head pushrod engine that's gonna have to be bored out or replaced. How much does a Predator/Lifan/etc 140 cost?

[@maskedavenger2578]

That ugly. adventure cub is beautiful ,& will get to places the high end BMW’ cannot get too.You can also get away with riding & parking in places you shouldn’t ,cops tend to find them inoffensive & turn a blind eye to them .The Australian post office used them & they call them postie bikes & delivered mail on them I have only seen one or two of them here in the UK .We mostly just got the standard step thru Honda Cubs with double seat & leg shields c 50 ,C 70 & C 90 & now the 125 Honda Super cub that is not good as it has become too high tech & not as owner friendly .

[@mrlong4269]

Has to be stuck in low gear right

[@NickMakesBreaksStuff]

nope, just an old and tired CT90 engine.

[@gmoney4797]

What aftermarket throttle did you use?

[@NickMakesBreaksStuff]

This is the one I used: dratv.com/sipuunthas7b.html There are certainly cheaper or nicer options available, I'm not super happy with the feel and quality of this one.

[@gmoney4797]

Where did you buy the engine?

[@NickMakesBreaksStuff]

I bought the engine from wholesale-cycles.com, they're local to me so I just picked it up. The throttle is just a generic universal throttle from online somewhere

[@ringer405]

Buy the motor off tbolt usa best website

[@croixtucker1757]

What's the max speed flat out with the new motor?

[@NickMakesBreaksStuff]

So far I've been able to acheive a GPS verified 53mph. I'm using the original exhaust which is way too restrictive for this engine. I'm looking at some other options, but for now, thats about where its at. I'm pretty happy with the performance overall, it is much peppier than any CT I've ridden before.

[@croixtucker1757]

@@NickMakesBreaksStuff hmm, I think one of the benefits of those bikes was the quieter stock exhaust on them.

[@NickMakesBreaksStuff]

@@croixtucker1757 Thats why I'm hesitant to change it. I like how quiet it is, even if it means a lower top speed

[@lreids]

How cheap is cheap?

[@NickMakesBreaksStuff]

fairly cheap

[@Jost_2008]

Is this a reliable engine

[@NickMakesBreaksStuff]

I haven’t had any issues with it so far, though I don’t put too many miles on it anymore

[@luvmtlife73]

Does still have low range?

[@NickMakesBreaksStuff]

No, it does not. Can't say I really mind though.

[@A67auto]

Nick, did you use the PIRANHA 140CC BOTTOM ELECTRIC START SEMI-AUTO E-START ENGINE? It's a 4 speed

[@nicholasdivitto4633]

Yes, that is the one I used.

[@rev5229]

Just ordered one from tbolt!

[@rev5229]

kzbin.info/www/bejne/rX3cpaagntaraKM

[@rev5229]

Just found this video about what we are talking about guys!

[@holdenheinrich4247]

What is the exact bracket from dr atv?

[@NickMakesBreaksStuff]

dratv.com/adchtob.html I only used one half of it. For some reason the left side did not line up with the hole on the bottom of the engine.

[@holdenheinrich4247]

@@NickMakesBreaksStuff thanks

[@thucpham5797]

How much

[@gerrynightingale9045]

*35???* &*WHAAAAAT?* *Sounds like it's in the 'Low' gear-range, because even a 'bone-stock' Trail-90 would easily reach 50-mph, even in the '60's era* *Something seriously weird is going on...!*

[@NickMakesBreaksStuff]

Nope, just a tired old CT90 engine.

[@gerrynightingale9045]

@@NickMakesBreaksStuff *The engine must've had compression-loss from a worn piston-ring and maybe a 'scoured' cylinder*

[@NickMakesBreaksStuff]

@@gerrynightingale9045 Any number of things could be wrong with it, the most glaring issue is that the clutch no longer engages. I'll get to it some day, but for now I'll continue to enjoy my 140 engine.

[@gerrynightingale9045]

@@NickMakesBreaksStuff *Yeah, clutches do wear-out, especially if it's been outside a lot because of 'moisture condensation' inside the casing which kills many bikes over time* *Engine DID run, which tells me it's worth a re-build if someone really wants the original engine that was on it* *The 'Lifan' really really upgrades the performance into the modern era, so I can't object to that!* *It would be another story if the machine were in 'very good' condition but it isn't* ___________ *'Mint' Hondas from the '60's in 'all original condition' are so rare now they're worth a fortune!* *I saw a Honda 70 'Passport' last year on 'CL' in my area that sold for $2,500!* ( *I remember when i could pick one up for $100 'gently used'* )

[@garryhatchett775]

Needs another gear.

[@Chris-s2e5t]

WHAT A PILE...I RODE THOSE WHEN NEW...

[@deborahchesser7375]

Wouldn’t take much to put her back to pretty

[@NickMakesBreaksStuff]

It is a good project bike to slowly piece back together and improve over time. Thanks for watching!

[@deborahchesser7375]

@@NickMakesBreaksStuff exactly, take your time and do it right. 👍