Making my Ruined 89 XT350 Reliable (Engine Refresh)

[@alexleggett6270]

Thanks for posting this. Im in the process of rebuilding my top end and clutch. I had to heli-coil the socket that takes the cam chain cover bolts. Seems like a common issue. This video was helpful and you had some good tips sprinkled through out that were more helpful than other videos of XT 350 rebuilds for sure. Im on the fence on whether to use the stock cam chain tensioner or not. Fairly certain the stock tensioner may have been the culprit of a bent valve the previous owner replaced on my bike. Anyways keep making XT 350 videos they are awesome!

[@HardAngle]

Thank you for that! I also blamed my tensioner but in this rebuild I admitted to myself I was never going to remember or want to check the manual chain tensioner. Also I had narrowed the original timing jump from years ago down to not the tensioner (since its mechanical and "technically" shouldn't get weaker with age) but the timing chain just being too stretched (worn) out.

[@keb-j9i]

Found this video and I'm in the exact same situation. Rebuilt my top end with the same wiseco piston a few years ago as a teen with very limited experience, I didn't torque anything and stripped out cam cap bolts just like you said you did too lol gonna do it right this time hopefully my cams/head aren't junk

[@HardAngle]

Hopefully yours will go as good or better than mine, Its still running, rode it last night after work so fingers crossed!

[@apodski]

I rebuilt a 1985 with a stock piston, as a forged piston tends to wear a lot more on startup with the greater bore clearance required. Rejetted the carbs for some derestriction. You have to be careful cutting the airbox, as it tends to make it resonate and hiccup at 4500 rpm. I used viton stem seals and a Vinton decompression shaft seal, would consider those required. I run a manual cam chain tensioner, like shown, have to wrap the threads in Teflon tape to seal. I replaced the oil pump gears. The TT350 flywheel bolts right on, works great, 1 lb lighter. Earlier kickstart shafts tend to break, later ones are different manufacturing -silver metal, they hold up. Trailtech cht sensor is good to have, but hard to squeeze in the tight spark plug hole. Over 400 is the danger zone for the piston and head. It's hard to get that high if it's running right. Mobile 1 20w50 oil works great and runs substantially cooler for some reason. I also use premium gas or it tends to knock when hot. I converted to all LED lighting, rewired all lights to the DC circuit. I use 2003 cr125r forks and a modified 2015 raptor 700r se 4-way shock. YZ triple clamps are a direct fit with some spacers. Ride is incredible. I adore this bike. I have 6k trouble free miles on it. Long stints of 65 mph on the highway and heavy off-road. It's bizarrely stable on the highway with the modified suspension, despite being 3 inches taller... And, it jumps like an mx bike. Haven't cracked the frame yet, but I'm light, 150 lbs.

[@callsign_x-ray]

so was there something holding your shift rod in place? i just went through and re built mine but im having an issue of my shifting rod moving left and right and wanted to know it something on the case held it in or if i would need to replace my shift rod

[@HardAngle]

I can't remember exactly but I do think on the right side case (clutch side) there was a snap ring or something similar that held the shift mechanism in place and also didn't allow the shift rod to move side to side when installed.

[@callsign_x-ray]

@@HardAnglethanks im missing that snap ring if it ever had one, but now i need to rebuild the carb so any website recommendations or?

[@HardAngle]

@@callsign_x-ray Honestly, anywhere you can find it, parts for these aren't always easy to find anymore

[@johnpembleton1919]

Have you ever put the vectors up to download?

[@HardAngle]

Could you elaborate on this a bit? I'm not sure what part of the video you are referring to.

[@johnpembleton1919]

You turn the gaskets into vectors so that you could cut them out on the laser. Did you ever take that file and upload it?

[@HardAngle]

@@johnpembleton1919 Ah yes, the gaskets, I forgot I did that, I did not think to upload them, I could do that so others with access to a cutter can make a set.

[@johnpembleton1919]

@@HardAngle Nice!

[@asmashan9781]

❤❤🤗🤗🤗😊

[@cmonkeynutz1186]

smoking because of the rings , piston and cylinder clearance is not true either the cylinder is not round or the bore is too large for the piston diameter being used. I did not notice : is there any evidence cross hatching in the cylinder? have you checked the cylinder bore for being true or out of round? where are the ring end gaps oriented on the piston, clearances of the ring end gaps? are the rings installed correct side up? any cracked rings? any excessive piston skirt to cylinder clearance is usually a noise long before oil burning is seen. the fact that the oil smoke in this case is not seen during deceleration indicates valve train is not likely the cause of this motor smoking. in this video we see increased smoking during acceleration and continued smoking during steady state rpm operation, this indicates a problem in the cylinder/piston/rings. check and verify the piston clearance, piston ring end gap clearances, end gap orientations, cracked or collapsed rings (oil rings), rings not installed correct side up, cylinder bore is round, cylinder walls are square, crank case ventilation system is not restricted or plugged, using correct engine oil I use a full synthetic 15w/40 for diesel engines & never had any problems. 🚫⚠️VERY IMPORTANT ⚠️ 🚫NEVER USE AUTOMOTIVE ENGINE OIL in your motorcycles!! * IF the valve train was compromised, it would smoke during deceleration

[@HardAngle]

This is the most detailed comment I have ever seen. So the cylinder was rebored only 200 miles before this but also the motor did not smoke until after I rebuilt it again, I did replace the valve stem seals on this rebuild so I do not think they should be leaking and the piston rings were still in good shape when I checked them before installing the cylinder. I think I will open up the engine again and check the tolerances between the piston and cylinder.

[@cmonkeynutz1186]

I would strongly recommend honing the cylinder and putting new rings in, rings are cheap enough, rings are not likely going to seal if there is no cross hatching seen in the cylinder bore also recommend using a conventional (not synthetic) oil for the initial break-in. the rings may not seat properly if using a synthetic. break in typically happens in less than 200 miles from my experiences. *forgot to mention I have a 92 XT 350 that is very modified - still have stock cams and piston for now. yes i am a tech/gearhead, professional mechanic/ technician since 84

[@HardAngle]

@@cmonkeynutz1186 Well in that case, when I get some free time maybe I will break out the bore gauge and give the cylinder a good measuring and give it a quick honing and a fresh set of rings, couldn't hurt.

[@ThatOneMinority]

should I switch and use synthetic 15w/40 for my bike exactly like this?

[@BurnerJones]

@@cmonkeynutz1186 What modifications have you done to yours? I've ground out the restriction in the inlet of the exhausts, opened up the back of the exhaust a bit, rejetted and converted the headlight and cluster lights to 12vdc. I've been looking for information on converting the oil pump and gears from plastic to metal, supposedly you can get the metal gears, pump and clutch basket from a tt350 and it will all drop in.