1987 Yamaha Warrior timing chain guides! Do I really need them?

[Silvacane]

New member here...hey everyone,

Well, here's my dilemma... I picked up this 1987 Yamaha warrior... [ didn't run ] hope I didn't get beat on this one.. anyway, the electric start didn't work so I'm in the process of putting in a new flywheel ... the woodruff key broke from the crankshaft.. in the process after taking the flywheel off I see that the plastic timing chain guide on the front side of the crank shaft has falling off... and looks like its a molded piece that it is made to fit in broke off somehow... my question is...is this guide vital to the timing chain?... i attached photos of what i saw when i opened up the side case. I am also changing out the stator while i have it open... I don't have spark yet..I changed out the solenoid, coil, ignition, regulator...and now the stator... hope it works ( to get spark ) but now I have this new issue... Any help on this matter would be highly appreciated...Thanks

[davefrombc]

While you're in there  I'd  change that timing sprocket too.  It's showing a fair bit of wear .. Yes,  you want those guides in place to  keep the  chain from  jumping on the  sprocket  and throwing  the valve timing  out. I don't  know  about that  motor but on some  motors if  the valve timing  is  out  or  the   chain  is  broken the piston  can  hit the  valves.. and  good  bye  motor.  Was  the  keyway in  the  crankshaft damaged?   You  could be  looking at some  major repairs to  the motor with a new  crankshaft in the  works if the  keyway  is slopped  out .

 

[Silvacane]

Yes thanks Dave for the reply, when I opened it up The keyway was missing, Looks like a Idiot put a rivet in near the damaged case to try and keep the guide in place. The lower guide fell out and wont stay on...I probably have to find a good left side engine case for it to function! The person I bought it from said he rebuilt the top end but now I'm afraid to open it up! YIKES!!!

[Silvacane]