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Discussion Starter #1
just got a top end rebuild on the mule, dropped the intake valve into the piston chamber and bent it in half (pictures soon)



the educated fellows at the shop suggested that I " ride it too hard/ too fast/ too much"



replaced the rear sprocket with a 47 tooth as i am doing a lot more highway riding, catastrophic failure occurred about 200 km afterwards



i felt confident riding at sustained rpms (the bike is under- carbed.. ) and never felt like the bike was going to "blow up" as some people do when ringing out a small engine.



do i throw caution to the wind and keep on thrashing this bike? or is it time for me to get something bigger






really do appreciate any advice



thanks
 

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I'd call it just plain old bad luck in your case. Move on, or even move up if you think that will better suit your needs, but valve train failure is one of the least reported issues on here.



The big elephant in the room for me would be the exact nature of the failure. Did the valve sieze in the guides and bend with the springs and keepers intact which would indicate either an oiling or valve float problem, or did the keepers let go and the valve simply hammered the piston? These are very different critters. One would indicate a possible clogged oil passage or use of crappy oil which could bite you again down the road, one would indicate sloppy attention to valve adjustments on your part which you can correct in the future and one is just plain luck of the draw.



You don't wanna go through this again. I'd ask.
 

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Riding a bike hard, in and of itself, shouldn't cause catastrophic failure like that. I think valve train failure is pretty darn common on the TW, unfortunately.
 

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just got a top end rebuild on the mule, dropped the intake valve into the piston chamber and bent it in half (pictures soon)



the educated fellows at the shop suggested that I " ride it too hard/ too fast/ too much"



replaced the rear sprocket with a 47 tooth as i am doing a lot more highway riding, catastrophic failure occurred about 200 km afterwards



i felt confident riding at sustained rpms (the bike is under- carbed.. ) and never felt like the bike was going to "blow up" as some people do when ringing out a small engine.



do i throw caution to the wind and keep on thrashing this bike? or is it time for me to get something bigger






really do appreciate any advice



thanks




What would keep you from flogging a bigger bike just as hard?
 

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Discussion Starter #5
i was suspicious of the cam shaft bearing being out of wack,as the valves would not stay within spec... as in they would adjust within minutes not hours or days. The valve adjustments were done by certified mechanics, as well as myself at times. Both had the same results, valves loosening themselves off. The valves were slapping like wild before the failure. Now that ive had a complete rebuild, the bike sounds like it did out of the showroom. No "marble in a box" noise, lots of power at 1/4 throttle and no slapping valves. Now im tripping out on other sounds i didnt hear before, but thats another day




I really didnt thrash the bike too hard, but certainly dont treat it like a harley.. i get stuck in the mud, flip it over on the trails and go 100 km/h to commute between towns.. is this too much to ask of the tw200? It did everything i asked of it until it imploded. One more thing to consider is that none of these mechanics own/ have ridden a tw for any great length of time- they are sport bike/ big dual sport guys. Sometimes i feel like they just scoff at the mule
and stop listening when i mention stuff i have read on the forums.



Can someone just confirm for me that they ride at 100km/h for over an hour without problems? Otherwise it may be time to say goodbye
 

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It is certainly possible that your top end failure was due to manufacturing defect or over-revving, but I wouldn't bet on it without seeing the parts. A manufacturing defect leading to a top end failure will usually cause the failure very early in the bike's life. As for over-revving, that would almost have to be done on purpose since a TW200 stops making power 2000+rpm before it floats the valves.



More likely the cause of top end failure is an oiling problem. This can take several forms.



First, the infamous 2-hole oil filter problem.



Second, using a modern engine oil that does not provide sufficient extreme pressure protection.



Third, operating the engine at an insufficient rpm to pump oil to the top end. This could be from lugging the engine against too tall a drive ratio or from insufficient idle speed.



EDIT: 100kph for extended lengths of time will not harm the engine. I've ridden that or faster 200+km at a time, refueled, topped the oil, then did it again, again, again, ..., for 1700+km in a day. Tdub has 77 xxxkm on her and still on the original top end parts.
 

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I've ridden at least 60/65 mph. for a 100 miles before.... Not often but I have done it with my riding buddy on his dub.... No problems.. I've "NEVER" had to add oil between changes.... It's stayed in the window... 9,000 miles now... I never ride it hard for the first 5 miles or so. Hardly ever punch it from zero to top end.... Broke it in by the book.. Both our bikes run the same... Mine does shift smoother, and feel smoother a 60+... OMM.
 

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Discussion Starter #8
It is certainly possible that your top end failure was due to manufacturing defect or over-revving, but I wouldn't bet on it without seeing the parts. A manufacturing defect leading to a top end failure will usually cause the failure very early in the bike's life. As for over-revving, that would almost have to be done on purpose since a TW200 stops making power 2000+rpm before it floats the valves.



More likely the cause of top end failure is an oiling problem. This can take several forms.



First, the infamous 2-hole oil filter problem.



Second, using a modern engine oil that does not provide sufficient extreme pressure protection.



Third, operating the engine at an insufficient rpm to pump oil to the top end. This could be from lugging the engine against too tall a drive ratio or from insufficient idle speed.



EDIT: 100kph for extended lengths of time will not harm the engine. I've ridden that or faster 200+km at a time, refueled, topped the oil, then did it again, again, again, ..., for 1700+km in a day. Tdub has 77 xxxkm on her and still on the original top end parts.


the mechanics didnt say anything about oil, and ive checked the 10mm/phillips head bolt that is on the top end constantly, and after oil changes.



im suspicious of an improper break in, as i got stuck in the mud very early in the bikes life. would a damaged piece last 5700km? i work in the shipyard, and have seen crazier things last a long long time so im well aware of the "magic"- sometimes things just keep ticking..



ive put another 100 km on it since the rebuild, and its running beautifully. One thing i have noticed is a small amount of oil weeping from under the cam chain adjuster somewhere (cant quite tell where) that only appears once the engine is shut off. Also it only appears on the left side of the bike, as it leans that way on the kickstand. Ide say half a teaspoon at most.
 
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