Vibration at rpm

pull the reed blocks out of it and then look in the engine via a mirror on a stick and see if the skirts on pistons are all there. How many miles are on this engine?
 

Also do u think if I got my belt wet it could bring about similar conditions? I’m missing the engine bay plug directly in front of my primary. I’m addition, to phase being fine I changed my belt and took it for a short rip and noticed a great improvement. No bog and I could hit 8400 again and from what I could tell no shake. But I still am not convinced it was just the belt. The belt is an 8dn genuine yammie belt with only about 150-180 on it??
 
I am convinced its the belt ! lol
I had same problem.
I also am missing the plug in front of primary, bad idea for sure.
 
I just can’t believe how terrible it ran that day and then after power washing it letting it thaw out and dry it ran great,(from what I can tell) I barely rode it cuz of poor conditions, but it seemed much better. Also I haven’t checked reeds or piston skirts, but I can’t imagin I’m missing a skirt since it reads 120 psi on all three And ran like it did Saturday. Still not 100% trusting it yet but we will see. At least I know phase is correct.
 
Also on another side note it has PSI pistons and rings not genuine Yamaha. Heard good things from people and it was a little less so I figured why not. Any opinions on this brand?
 
5000 total but only about 250-300 on rings pistons and crank seals

likely not the problem then, you don't know what your dealing with until you keep asking questions,. if it runs great now after washing it then I have no idea as to whats wrong with it!
 
Hate to be the guy that does this but the sled is doing it again. No water on belt, crank phase is good, sled was clean when I took it out, piston skirts are good, I’m at my wits end with this thing. Also I’m now noticing a clunking sound below gas tank when I punch it from coasting. I’m going to pull my skid drive shaft and jack shaft and go through it. Also when my primary disengages is getting a slight squeal. Sounds just like when you hit the break but I can tell it’s the primary. No idea
What I’m gonna do if I pull drive train and can’t find a problem
 
Squeal is belt deflection, pull the 3 screws out of the back of the secondary, remove the washers, reinstall screws. This will split the sheaves a touch more, once the belt is wore down a bit, reinstall washers.
 
So less washers means the belt will ride higher in secondary? Correct? And adding washers will make it ride lower?

Ahh never mind I reread that again and see what your saying. Only thing is tho about that is belt is at the perfect height in secondary. The little nubz are jus barely higher than outside of secondary
 
Also gonna be buying an srx hopefully tomm. So I’m debating just doing a full restore on this sled. Send In crank and have it tried and welded, and go through whole thing and put an sc4 viper or edge suspension under it
 
Just checked crank runout less than .001. Was better results than I expected. Looks as tho it’s in drive train. Gonna pull skid this weekend and update. If I can’t find a problem than I’m have no choice but to just ring this sled out for what it’s got and see what gives. Motors good so long as it isn’t a bad crank bearing, but I doubt it being a Yamaha with only 5000 on it. Plus mechanic I had do the crank seals and top end said bearings were good
 


Back
Top