CRF150R Engine Teardown | It's real ugly!

[@daveh.8488]

I picked up an 07 crf150rb project/basket case bike a few weeks ago for $400 that was locked up. It looked almost identical to yours when I cracked it open, but the hole in the case halves on mine were a lot bigger. I bought the right case half and need to find a left one cheap now. I said screw it. I'll rebuild it.

[@GarageAddiction]

Man I would love to find a cheap 150r anywhere near me haha. Good luck with the rebuild!

[@raywang6528]

Man, sorry to see that the engine blew... Keep us posted on your 2022!

[@GarageAddiction]

Will do! Hopefully back in action real soon here.

[@brianschuit8271]

I just got a locked up 07 150rb and started to open it up too! I was excited to see your video come up and understand why you wont be rebuilding this engine.. I was hoping for step by step rebuild video to follow though!.. ps can i have your clutch? 😉

[@GarageAddiction]

I was looking forward to a rebuild too. Maybe on the next one. I have the clutch listed on ebay/facebook shoot me an email and I'll give you a sweet deal.

[@brianschuit8271]

@@GarageAddiction where can I find your email?

[@GarageAddiction]

@@brianschuit8271 [e-mail]

[@garbageman3992]

conrod failures are almost always caused by pushing a steel or metal piece past its infinite fatigue limit too long, I can help boil down the cause a bit. How many hours did the bottom end/conrod have on it? what type of riding do you do with it? for your type of riding do you rev your motor high a lot? basically the thing that kills conrods is revving the engine high, not oil supply or anything like that because that kills the cylinder and bearing first so I'm sure your oil was clean enough and your oil squirter was fine. keeping the motor revs below 2/3 of the total rev range ensures that the conrod will last basically forever, at those rpm's the conrod is not under much strain and will not become weaker with time or usage but revving the motor above2/3 of the total rev range or to where it makes peak power output subjects the conrod to too much force and it becomes weaker every time it is subject to those forces. so basically im just asking for how many hours the conrod had on it and how often you revved the motor really high. based off of the teardown I can almost grantee you did rev it high a lot and that is the cause of the failures, if not then it could have been a faulty rod or it just had too many hours on it. those 150r motors try to make way too much power and need rebuilds all the time so it could have just been a high hour motor. also i would like ot know this info just for personal experience so I get a better idea of when i need to rebuild my motors.

[@GarageAddiction]

Unknown hours on the crank, I bought it, checked the valves, changed the oil and was off to the races. I run supermoto on varying tracks. I avoid limiter but run high into the rev range. Fresh motul oil more often than necessary with a new filter ever other oil drop. The crank didn't look like it got hot at all. Guessing the combo of big bore, unknown hours, and hard riding was the downfall. I've never had an issue with hot rods cranks but in this application I'd probably avoid them in the future.

[@garbageman3992]

@@GarageAddiction yeah I didnt realize it was a hotrod aftermarket conrod. I have heard some questionable things about them, they seem to be sub par production quality, some of em last forever and others blow up from what iv heard but take that with a grain of salt. i didn't realize it was a big bore either. you are right about the crank not getting hot and your maintenance was obviously not the issue so it seems like the issue was either a bad hotrod conrod, the big bore resulting in extra force on the rod so that it becomes weaker quicker, and a lot of hours on the motor. a combination of these it the issue but i cant boil it down to exactly what because we don't know the hours on the parts. your maintenance was great though so that is not the problem. anyways sorry your bike had to suffer that fate and sorry for these long comments.

[@GarageAddiction]

Thanks! Going back to stock with a nice 2022 low hour bike. Should be nice to start from a known baseline this time.

[@garbageman3992]

@@GarageAddiction yeah its always nice reassuring to know exactly what your bike has gone through and when it needs work rather than having no clue if it will blow up this or next ride.

[@thetrainmaster.100]

What oil are you running? That could be why it blew up

[@blaster5064]

Time to dust off the KX

[@GarageAddiction]

Haha yep, it's gotten some good use lately.

[@MrGeorgeisonit]

Whooaa! That piston tried to reach the moon! Sorry to see this happened. Was there any warning signs?

[@GarageAddiction]

It was the single most violent off I've had on a mini. Coming out of the turn the rear immediately locked up and by the time I found the clutch I was sliding off the edge of the track. The rider behind said he never saw that much smoke pour off a 12 inch mini tire in his life haha

[@MrGeorgeisonit]

​@@GarageAddiction whooaa! That's rough. Glad you're OK, maybe the cases can be split down and welded up?

[@GarageAddiction]

I sent them over to someone who's going to use them as a test bench setup. By the time I get it welded and re-bored I'd probably be into it way more than they're worth.

[@MrGeorgeisonit]

@@GarageAddiction yeah fair point. What will become of the crf?

[@GarageAddiction]

@@MrGeorgeisonit New engine slammed in!

[@dixondai]

oh man, fun video though!

[@GarageAddiction]

Very unexpected haha

[@walterdemo2895]

Not fun but is a good time for CR125 option

[@eternalreflections7699]

Holy crap! 65 time!

[@GarageAddiction]

Been rocking the 65 for the last few months while I wait on a new engine :)

[@trentbikes]

A whole new engine? Why not just buy a new crankcase and head, reuse the rest

[@GarageAddiction]

I could but by the time I get the cases, cylinder, piston, and crank I'm pretty close to a low hour complete engine. Also I have a line on a sweet 2022 complete bike :)

[@rebekahfrench5747]

Thats the joys of balance shaft , rod failure.. they all making cheap junk to save a dollar.. but the rev limiter heroes of today can turn everything to scrap.. if you rely on the rev limiter you seriously need to lear how to ride a bike..

[@GarageAddiction]

Yeah luckily 99% of the racers around here know the limiter is expensive lol