85 Tri-z Overheat/rev

[triz85]

I just put together a nice 85 Tri-z, but after a few minutes it starts to overheat and when you let off the throttle it is still at high rpms. The motor in it sat for about 4 years - oil has been changed/carb cleaned and piston appeared fine when looking through intake/exhaust outlet. Carb slide is fine and it idles great when first started- no problems starting. I think it is sucking air somewhere. Carb seems to be fit properly along with intake. Faulty fuel pump gaskets or carb problems?? Any input appreciated for diagnosing. I did blow out the fuel lines and rinsed gas tank prior to assembling, but it is possible that some residual crud may have been left.(no chunks on initial flush)

[gojk]

perform a leak down test

http://www.exriders.com/vbb/showthread.php?s=&threadid=265369

I would bet on a gasket leaking somewhere.

[John451]

Yeah, it might be a leak. Im not too sure about the overheating though.. do you have enough radiator fluid? But you should also check around the intake boot on the carb. between the engine. Bend it around to see if it bends and see if any cracks open up, if they do, you can just put gasket sealler all over the outside and itl work.

[Drewltr450]

nvrmnd

[triz85]

Thanks for all the info, I'm going to tear down and replace all gaskets and seals over the winter since most are original equipment and I've got the parts now anyway. I talked to a Yamaha mechanic and he thinks it's either the intake boot or possibly the seal behind the stator. I'll also check the cooling system for obstruction/thermostat problems since I have not yet flushed the entire system.

[triz85]

Here's a pic of my other Tri-z (I'm the original owner). Just rebuilt/new waterpump/bars, has cobra exhaust/boyeseen reeds.

[John451]

Iv always wanted a tri-z..