XR150L / CRF150 300CC Big Bore Pt.1

[@smileyguyz]

And I thought my 64.5mm piston was big! This is awesome

[@DustySteel]

@@smileyguyz thank you for watching!! Hey Ryan!! How’s it going? Haven’t heard from you in a while.

[@smileyguyz]

@@DustySteel Pretty good overall. Just been beating the hell out of my XR to find the weak points. There aren't many lol. I'll be posting an update video eventually here, just gotta get some other bikes fixed first.

[@MishMashMoto]

@@smileyguyz I subbed. 👍🏼👍🏼

[@DustySteel]

@@smileyguyz nice! That’s good to hear that you’re doing well. Nice! You got some other bikes?

[@smileyguyz]

@@DustySteel Yup, I've got some other more dirt focused bikes & I like to rebuild bikes too.

[@Yt_xrider]

Im excited,this looks fun.i also want my bike to have this size of piston soon.Excited silent viewer here👍🏻

[@DustySteel]

@@Yt_xrider thank you for liking and subscribing if that was you; you’re awesome!! I’m very excited also, just waiting on parts lol. No need to be silent, I like when people comment and talk about the projects.

[@Yt_xrider]

@@DustySteel i enjoy this kind of content,what size of valves are you gonna use?i think your bike would be a monster if you use 4valve heads. but i think the issue would be overheating.

[@DustySteel]

@@Yt_xrider I’ve considered going to a 4 valve but already have a 39/34 head in the making. I’m definitely going to upgrade the oil pump and probably add an oil cooler or two.

[@DustySteel]

@@Yt_xrider as for power… let’s just say that I’m not just stopping with the 78mm.😎

[@Yt_xrider]

@@DustySteel 👍🏻🙂 nice,so you do the machining yourself? Could you maybe make a video on how to oversize the valves.

[@MishMashMoto]

I want the 36/31 head and carb. if you decide to sell them. If you stroke it, think about where that extra 4.2mm of stroke is going to place the piston at BDC and TDC!!! You will also want to make sure of your valve to piston clearances. Your deck height will become critical info for this build.

[@DustySteel]

@@MishMashMoto okay; I was going to try and get my money back for the head though. Yeah, I was hoping the piston had the indents on the piston for the valves so I didn’t have to worry about it as much. If people use the +4.2mm then in theory it should work, right? I know I’ll have to run that 1mm gasket for sure!

[@MishMashMoto]

@DustySteel Sounds fair enough to me on the head. That all depends on the deck height of the piston with a 4.2mm stroked crank. You can calculate it with all the specific measurement info. You can normally alter things like piston pin location (probably not in this case) and use a taller cylinder to increase your deck height clearance. I don't know all the specs on those parts to help you though. The 1mm spacer is probably for extra deck spacing. You will need to precisely measure everything and do some calculations to know your compression ratio and clearances (unless this is a pre-enginered kit with instructions). That piston is only going to be "correct" for either a XR150L stock stroke or a +4.2mm "stroker" crank though.

[@MishMashMoto]

@DustySteel Is that cylinder about an 1/8" taller than the other cylinder? If so, your probably good with the +4.2mm stroke, but check everything anyway.

[@DustySteel]

@@MishMashMoto it might be. I never measured the stock one but after I put the 70mm cylinder in I noticed that at TDC the piston was below the deck height by like 3-4mm.

[@KatieJackson-t4m]

@@MishMashMoto i do know you do need a piston head that accounts for the stroke increase.

[@sambendasilva8174]

One of the unbreakable bikes from Honda,here in India it's called "HERO Impulse"🔥

[@DustySteel]

@@sambendasilva8174 that’s cool! Thanks for watching and subscribing if that was you!

[@DustySteel]

Very cool! Thanks for watching and subbing; if that was you.

[@2_Wheel_Waldo]

Holy shit looks big as a piston from one of my V8s

[@DustySteel]

@@2_Wheel_Waldo it’s huge!! Thanks for watching and subscribing if that was you!

[@2_Wheel_Waldo]

@@DustySteel yessir i subbed! Love to help support Any of the Goat army

[@DustySteel]

@@2_Wheel_Waldo thank you sir!! I also subbed.

[@Brandon-fv7rc]

Be very careful not having details on valve dimples and compression. It looks like around 11:1 compression . I would do a clay trst for clearance on valve to piston. Luckily if you don't like the piston you can get a piston kit for the valve size and compression you want.

[@DustySteel]

@@Brandon-fv7rc thanks for watching and for the info! I’m definitely going to have to do that.

[@DustySteel]

@@Brandon-fv7rc dimples… is that the name for the clearances on top of the piston for the valves?

[@KatieJackson-t4m]

@@DustySteel yeah i dont know what to call it i just know how to check the clearance lol. i used played doe just add oil so it doesnt stick to valves i think you want it to stick to piston.

[@DustySteel]

@@KatieJackson-t4m hey I have that!🤣 Then I can measure the thickness of play-doh. I thought clay had to be used, though that’s probably not hard to get either. That helps a lot because I thought I had to take it somewhere to have that done. I’m going to do more research on that! Thank you!

[@Brandon-fv7rc]

Its an annoying process to put things together and back apart and back together ​@DustySteel

[@AliasTekTV]

I can see this for a performance perspective, but the thin wall cylinder on an air cooled engine is not long for this world. Large discussions in the air cooled VW world where cylinders warp and cause sealing issues. Just something to keep in mind.

[@DustySteel]

@@AliasTekTV thanks for watching!! I’m definitely not staying with the stock cooling system.

[@DustySteel]

@@AliasTekTV one of the first mods I did to my Audi was put in a custom Mishimoto radiator. Cooling is definitely a priority in any build. I probably won’t be racing it or running it wide open for long periods of time. I really appreciate your advice though and I’m a huge fan of the Audi/VW world. Really anything that goes fast.

[@MishMashMoto]

@@AliasTekTV Agreed, I personally believe most of the sealing issues on the old aircooled VW engine builds were due to people not using "torque plates" while the machine work was being performed. I ran 90.5mm cylinders on my hotrod VW bug because of the extra cylinder wall thickness. 👍🏼👍🏼

[@DustySteel]

I definitely understand though that the thinner wall won’t last as long no matter how much cooling a do. Putting a big bore kit in general will definitely make parts wear out faster. I don’t know why I didn’t add to that to begin with lol.

[@shockadellick]

@@DustySteel For over 10 plus years Brazilian's CRF230 have been bored to 270cc without issues. The CRF230 and XR150 share almost identical motors. The 230F has a 6 speed gear box, however, many Brazilians use the 230F's head cylinder on their 150F. The 150f and XR150 motors are identical in every way. Another side note: The 150F/230F, Nor the XR150 can be made to receive 290cc. The Brazilian, however, found a way but it requires more than splitting the crank case. The only thing that truly separates the 150XR from the CRF150 is the chassis. The CRF150F has an aluminum swing arm, where the XR's is made of steel. The CRF150F has the capability to have a linkage for suspension where the XR does not. The CRF150F has aluminum rims where the XR150 has steel. The CRF fame allows foot peg adapter relocation. The CRF150 is the racing version of the XR150 due to upgraded parts, otherwise they are identical platforms.

[@rnkustomz]

You close to iowa by chance? Need help replicating this setup haha. Subbed!

[@DustySteel]

@@rnkustomz thanks for watching and subbing!! Unfortunately I do not live near Iowa.😂

[@user-rek6]

thank you bro for your. video. I'm living on the Philippines now and have xr150 too, already second one. on my first was about 80k odo and already 14k on my new. I use it every day and for travel too. it is strange, but my old xr150 was more strong and fast, can't understand it. I'm looking for encrease top speed, but I think 120kmh will be enought for me. I don't want to reduce engine life. I doubt between 66 or 70 bore kits.

[@DustySteel]

@@user-rek6 thank you for watching and subscribing if that was you! Wow, 80k is pretty good! Is the carb and emissions the same with the new bike?

[@user-rek6]

@@DustySteel yes, both of xr have carburators. I compared it, it was the same brand and name pz27, but with small differents. old have one additional membrane to control backfire. I tried to put old carb on new bike, power and speed was the same. I tried to change main jet, it become a.little bit better, but not like old one anyway. So I looking for big bore kit to increase torque and maximum speed a little bit. it is enought for me for every day, I'm 70kg weight, but I need more power for long drive (travel) and for ride with passenger. we have cheap kits here, about 40$, I'm not sure about quality, but anyway price is fair and I want to try.

[@DustySteel]

@@user-rek6 I wonder if maybe the heads are different? Not really sure why they are so different in power.

[@DustySteel]

@@user-rek6 I originally bought a cheap 70mm BBK and it ran okay. I had to customize the bottom of the piston. If you can get BRT Racing for cheap then I would go with that.

[@user-rek6]

@@DustySteel I think even if this cheap kit have a low robust and will die in 30-50k - I can put stock one back anytime 😎

[@adamloveshondas3122]

Great video I’m considering getting the 150 it’s seems to be a great bike here’s an idea wonder how much it would cost to swap the vins on the frame between the street legal version to the dirt only crf it has better suspension and disk breaks front and rear now you got a frame swap and all you did was swap vins for about 100bucks along with a stonger moter😂🤣😂

[@DustySteel]

@@adamloveshondas3122 that would be cool! Thanks for watching!😎👍

[@AmrinderSingh-zx9hr]

Are want to sell of your previous parts ie Cylinder head, valves,😊cylinder & Piston etc.

[@DustySteel]

@@AmrinderSingh-zx9hr thanks for watching and subbing, it’s greatly appreciated! All of the top end including the carb is sold already. New parts should be here soon with an updated video.