$8000 Freshly Rebuilt Dirt Bike Has a HUGE Problem 

That zipp tied seat cover is driving me crazy 😂

Man, $8,000 in repairs and he didn't even replace the piston, port the head, get new valves, or seals??? Most of that must have been mainly labor

These diagnostic tear down videos are interesting. Joe could have saved this kid a lot of money. At least now he'll be able to ride the bike. Great work Joe.

anyone spending 8k on a 2005 should get their brain scanned.

Yep, for a forged racing piston .003" is about all you want. In a race car engine, anything over that will knock like crazy, especially cold. 35 year bike tech here, and still learning every day! Learn things from this young man's channel too!!! Thanks for great content man!

I must say broskie your attention to detail is reminding me of military,the hurry up and wait game you know. When I got out I got factory certs and wish in some classes you were there ..25 years later and still learning thank you….🎉🎉…I wish I had a bike , my go to was my 93 kx250 and 83 cr500 .. God bless… I’ve been watching every video this last week …

Hey bud I’m a car mechanic but watching your channel has taught me a tone about fixing bikes and quads.Great content and teacher.thank you bud.

Great video , So interesting and informative. I would get new valves as well .There could be an issue with them wearing out the seals prematurely. If your going to change the piston ,rings ,cylinder and valve seals ,you may as well cover all your bases. Just my two cents worth . The main problem of oil burning was the bad valve and seal . Cheers from Ontario .

Dude, your instincts and diagnostic talent continues to impress! Love the channel and watching you fix cool vintage bikes! Keep up the awesome work!

@10:30 I'd say valve stem seals, something a lot of people overlook on builds. If I remember right the last vid intake side was super tight before you adjusted them, probably ballooned the valve stem/roller mating surface and may have bent them a little. Valves are actually made of fairly soft metals unless aftermarket.

Really liking the way you are diagnosing the bikes... Great job!... I'm really digging your channel... keep up the great work 👍. This one was a head turner from the start... ,but you are showing it ,and ty. I'm 53 now and still love learning... old and new... thanks man!

One of the bikes I worked on, the previous owner had done new rings but somehow managed to get one of the oil wiper rings crossed over the other 2. Smoked like a fright train, had nothing for power but all the ring gaps checked out. Definitely a head scratcher

I love your descriptions.... I learn alot by watching your process! Thx for sharing!

Thank you for giving explanations as do things. Super helpful for understanding. I’ve learned a ton from your channel.

Your thorough mechanical step by step videos are fascinating but you're making me want to buy bikes 🏍 and work on them lol. Awesome video Joe!

He spent a lot of money on good parts, he just didn't spend on the right stuff. Great job diagnosing.

Love the channel, always a learning moment. BRAVO for your patience. Frustrating, keep working the problem

Another great tear down glad we got to see why a person’s learns from measuring .

if i paid 8k for that bike id want sectioning in a mental hospital 🏥

Nice intro. Is the muffler baffle saturated with unburnt fuel? Solid diagnosis. Wouldn’t a leak down test leak air past valve guide seals?

Great video Joe definitely agree you learn with experience you should always check to see if the piston if a good fit for the cylinder & always check the valve's & seals especially if your in doing a top end ashame the guy has spent a ton of money 💰 but at least he knows now these parts will fix the bike properly he could learn a valuable lesson on this we all have learnt over time with experience I know I have when I was younger in my teens trying to get things running quickly but you learn to check everything & not cut corners but once it is done he will have a nice reliable bike that he can enjoy riding & he will have learnt some things to check in future if he is rebuilding the bike one thing I give him credit on the bolts were tight on the top end I hate seeing lose bolts can't wait for the next episode & first ride on this bike I think it will run nice & have plenty power have a great evening enjoy your week mate great on diagnosing the problem that's why i enjoy your videos so much 👊💨

You need to invest in a good quality bore gauge and measure across from right to left as well as across the thrust faces (front to back) where most of the wear occurs. The measurements should be taken at several levels from top to bottom as well.

BRAVO, we admire your persistence and ability to work through problems.

17:30 this is an excellent demonstration of how NOT to remove the cylinder head!! Bolts should be removed incrementally! Start by turning the first bolt, half to two turns, then continue in a criss cross pattern. After each of the four have been loosened, continue to remove the bolts incrementally, in two more stages. This parctice will save you from breaking a bolt, or destroying the threads in the motor. You should notice how much torque was stored in that last bolt you removed, and recognize that as an issue.

I was thinking that the gap between the piston rings or orientation and man you turn out to be pretty good mechanic my friend God has blessed you with talents be safe God bless

As you mentioned $8,000 worth of repairs, I would have assumed the piston and valve components were replaced! I would have guessed an accidental coolant leak into the cylinder - but then that would have changed the colour of the coolant…. Meh. Great video Joe. Thanks for the upload.

I think the smoke was actually coming from 8,000 dollar bills burning up!

Had sort of the same issue with my 2006 kx450, that and trying to find someone to weld a couple spots on the engine case. Hard to find honest techs nowadays.

Imagine putting $8,000 into a bike, never getting to ride it, and have to rebuild it. Unbelievable lol

Honestly as a qc inspector for a machine shop I wouldn't have figured .007 was that bad that's .0035 a side. Just didn't seem outrageous considering you have rings as well. Shows what I know lol great videos always enjoy the diagnoses.

Good work Joe. You have came a long way in a few years of bike tech.

I believe the valve seals are different for intake and exhaust on the crfs possibly who ever rebuilt it before you mixed up the seals and that's why they were loose on the exhaust valves same with the keepers and springs to

Lovin the in depth content! Hoping to see a TW200 soon!

I guess people don't understand what a "Rebuild" really is. Yikes, great job determining what was really wrong with it. The dude should never take his bike to whoever "rebuilt" it last time.

How could that dude be smart enough to replace the crank correctly but not some valve seals it's crazy

I had an engine rebuild for a bike I restored and it smoked like a fire pit. I pulled the head and intake valves, the side that was smoking (twin cylinder) had a torn intake seal. Replaced it and all was well. No smoking.

Had similar issues with a buddies CRF450: hard starting, excess smoke, etc. Turned out to be worn valves/seats.

Can’t wait to found out the issue!

Loving the consistent uploads as well!

thanks for sharing this; it is crazy the money people will throw at something that must have been beat. i think to myself why didn't that guy find a better project? He definitely should have brought it to you from the start.

Every time I do a top-end job especially if the cylinder was bored and honed I always use a new piston and rings

What torque wrench do you have? Awesome fix to! I am looking forward to a cool old snowmobile or something like the 340tt Raider.

What would you recommend I upgrade first on a trx450r atv? Jut curious cuz I don't work on these like you do

Thank you for such an in depth look at this engine, great video again

Hey man I have a super clean ltz400. Everything is mint on it accept the bottom of the frame is kinda scratched up and there is surface rust where the paint is gone. I can dm u on insta but the bike is so clean I’m not sure if I should just leave it and put a skid plate on or powder coat it. Thanks. Love the consistent uploads man!!!

LOVE THE DIRTBIKE CONTENT!!!!!! Thanks

Good video man I'm doing the same thing on a grizzly 125 changing Piston and Rings I had 72 pounds compression my first one doing myself wish me luck

Nice work and diagnosis👍

Those valve guides might be worn as well. There are gauges for measuring valve guides too and tools for knurling and reaming them. I like knurling worn out guides instead of replacing them.

What a tidy bike just a seat cover fitted properly but keep up with what you’re doing I look forward for every post 👍

This is definitely my favorite channel now.

Hi, at the beginning of the video when you started it up it seemed to me it did not make a lot of smoke right away. Only 15-20 seconds after the start much more smoke came out. Comparing to chainsaws (I am just a beginner) it is said one must let the engine warm up at least 30 seconds before revving it up because the piston expands first and much faster than the cylinder. Maybe in this case, when the cylinder was warming up and expanding, then it produced even more smoke because the gap increased. If that makes sense. Obviously, there were other problems too. Thanks for the interesting video, good job!

As far as oil goes....when i was a kid of about 22...i worked at a Shell station in Schererville,Indiana.This one kid came in with his car saying.....i just chaned the oil and it smokes and runs terrable.I checked the dip stick and it was pure oil every time.He said.....i was checking this dip stick...(his trans)....and it never showed it was topped off.The kid had almost ten quarts + because he wasnt sure how much he put in.It was his parents car and he was nervous.I got it up on lift and drained out all the new oil.Measured off five quarts for a chevy sb.....and walla.....after the engine ran for a few mins....it was back to normal.That kid brough me a case of beer later that evening.My boss asked me....whats that all about.I just said.....oh.....he just owed me a case of beer...lol

I will say I do like the clean Garage/Shop 👍

Been watching your vids for along time now and I finally bought a qaud to fix the problem I’m having is when I adjust the valves and I turn over the motor a couple of time the adjustment is off again ether to tight or to lose what do you think the problem is? If anyone could help me out

Similar problem happened to me and my 2007 Crf450r. The previous owner installed an oversized flywheel and ran just fine. Slowly the bike became harder and harder to start and eventually stopped running. Odd thing is that it would start when it's cold, but when it warmed up, it would stall and not start. Took it to dealership and after months they couldn't figure it out. When I got it back I popped stator cover off and saw that the contacts on the pickup coil were flat and shiny. It was rubbing on the flywheel. I bought a new pickup coil and soldered the wires flat and cut down the tabs so they wouldn't rub and started right up. What an adventure that was.

It's possible that piston is causing that excessive smoking from side to side.& The up& down motion of the the wrist pin bearing sleeve.

Looks like the front brake line is incorrectly installed too. Interesting video 👍

The lectrons and smart carbs dont like the throttle being twisted when you kick them. Less signal strength, less fuel, and they probably wont start. Might not need to squirt gas down the intake if you just kept your hand off the throttle.

Hey hey. Great video ..I am beyond furstrated with my 1991 rm 125 .Brought it to 2 dealers Still wont start ...FIrst said it was the CDI box so i got a new Cdi box No start Scond one said it could be the Coil ..Bought new coil .No start ....Wish you lived closer I would drop the bike off with you ..Its like im in a love hate relationship with this bike ..It was running perfect after nickasiled jug and new pisten rings and clutch plates

Why leave the rear subframe attached by the one bolt? Would it of been that hard to just remove and set it off to the side?

For saying that’s had a rebuild that cylinder look very shiny so I wonder if the rings sealing because the cylinder wasn’t honed

I think all that smoke is from the seals. The piston is worn a little but with the new rings, it would have been okay.

You need to invest in one of those bore inspection cameras I love mine it's probably the best tool I own for under $100

I like the way you are humble about admitting that you made the same mistakes too. Looking forward to the startup, I'm sure the smoke will be gone.

Nothing short of amazed you still don’t own a harbor freight motorcycle lift. Game changer. I’ve been in here saying this forever! Cmon now! Lol. I’d GIVE you one if I could. Worth the money 100%.

I havent watched yet. Another thing to check is the float. If it's set too low in the bowl, it won't enable feul inside. If it was too high, you'd see gas spewing out of it. So the latter is probably not the case and things could make sense with this possibility.

It's clean on the intake side and dirty on the exhaust side of the ports as it's pulling clean fuel in through those intake ports and expelling whatever is in the cylinder out of the exhaust so if it was burning oil and something like that that could be a sign of that

Why all the cold revs

What did dude put $8,000 into I don't see it

Joe, Your channel is easy to watch and very informational as well. Your calm demeanor and patience is what makes your videos such a pleasure to watch. You are smart and seem like a nice guy. Wish I had your patience and your calm demeanor. I don't so I watch you instead. Terry

Joe is awesome at fixing all small engines don't mater what brand . I think if anyone can fix this thing it will be him.

I'll watch the grand finale next, but these 4 strokes have an issue with warped cylinders or heads, they have to be checked for flatness and decked. Or, they don't seal and you get 50PSI compression. It may just be your valves, but I've seen many warped cylinders.

I'm guessing valve seals based on how it was smoking. Smoke didn't really increase during rev up like it would if it was rings.

many lectron owner have reported hard to start when the bike sitting for more than a day, i found the issue by blowing thru the vent bowl, bike will start right up.. and tips after you done riding close the petcook and let the bike run until the bowl empty, next time u ride just open the petcock and it will have enough pressure to start the bike without blowing thru the vent again.

When you found the valve seal problem, did you then check for valve/valve guide wear? There's a reason those seals have gone that bad. You don't check piston wear like that. The measurement that matters is on the thrust face. Your piston ring gaps were fine. If the piston was worn, the symptom is piston slap when cold. The problem is undoubtedly, and singly - the oil seals, and you should check for valve & guide wear by inserting the valve into the guide and rocking the valve side to side. Like the vids though man :-)

Don't forget that you did squirt oil on top of the piston in the previous vid. Could be be where the smoking was coming from

i had a lectron on one of my bikes causing very very hard cold starts, also was making the bike run very lean just like the typical lectron. ended up switching back to oem carb. But i found a trick with those lectrons for priming them take the breather hoses and clog 2 with your fingers and blow in the other one and it will fire first kick every time no matter how cold

I have to admit, this guy is a great mechanic, I watch his videos All the time,

IT IS HAVING A WIERD SOUND ...THANKS A LOT FOR YOUR VIDEO ..MICHELL. NORWAY 👍🏻😊

Incredible diagnostic skills👏🏻👏🏻👏🏻👏🏻

Keep up the Good work!

The tip of the valve can get mushroomed over and then when you pull it out could damage the valve guide. If you go to take a valve and its stuck like this you should use a file around the edge to remove this mushroomed metal.

Great diagnosis....Great channel

Crazy who people will trust to do their mechanical work. You are definitely worth the big $$$ and making sure everything is done right. Was it the owner who did their own rebuild or some half-assed shop that claimed they could save him a few bucks? It's sometimes hard to find that shop or mechanic that can actually do the work you want without issues...

Looking at how much Smoke the Exhaust is Spitting Out makes me wonder if any Unburnt Oil has been Collected in the Silencer?

This is why I build my own bikes. Quarter of the price with everything new... that guy got ripped off!

I watched the first one and I bet the rings are not gaped right and maybe bad valve seals

Good work man figured it out

If the valves are cupped when you look at it from the side where the valve contacts the valve seat then they're bad,I thought the cylinder looked glazed

Love this keep them coming

omg look at that wrist go brother!! LMFAO!! oh and the smoke could have something to do with valve guides

It's the lectron carb I had one on my klr 650 a d I smoked like a chimney until I adjusted it

Cylinder head surfaced by hand with sand paper and red locktight on the head gasket is never a good sign lol.

worn valve guides and valve seals can cause the engine to smoke, if the piston and rings and cylinder are good and in spec then it is more than likely going to be an issue with the valves and cylinder head

As an ex-owner of a '04 250x (very similar to a 250r of this year) I can say they are very disliked bikes for starting characteristics, valve reliability and maintenance demand. I bought mine without knowledge of this as the owner prewarmed it and got home to a bike that did not start at all. Found the valves to be way out of adjustable needing a top end rebuild. Using near minimal shims and a carb rebuild it actually started and ran. But I sold it. These have terrible valves where they simply pound the hell out of the head. Sure I could have bought new valves and head for $1k but got screwed for paying 3200 for the bike. At that point I shimmed the valves and sold the bike, got only 2k for it as it also had a clutch issue. These bikes are a great concept but honestly suck. If I were to buy another 4 stroke it would be an older XR or a Yamaha. These just have poor reliability. Spent many hours just getting it to run and I promise you this will have issues within 50 hours if not upgraded to better valves /springs. I got a new Gasgas 300 and love it, 2 strokes it is for me. These year Hondas just aren't worth the investment...$8k is ridiculous in my opinion.

On a 4-stroke motorcycle, how is the crankcase normally vented?

Bravo nearing 300k subs, where are the sponsors and merch

Cause if their leaking at all it can cause it to burn up piston&rings& wear out those valve guide seals again due to that alone.

Great video man