Tri-z250

[port1]

Hi can any one help me I have a Tri-z 250 race tuned I have only been on it twice it starts up ok and seems to have plenty of power second time out it just slowed down but keeps running and I have all so found out when you but the throttle on it blowed the vacuum pipe out at the bottom of the cylinder could this men it
Needs a rebore please can any one help thanks Phill.

[NeverLift]

It slowed down because there was no longer a working fuel pump. Check the compressing just to be sure the motor is ok. But I had the exact same thing happen with the vacuum fitting. I put a little JB weld around the base of the fitting and reinstalled let stand for 24 hours and I've been riding with it like that for 3 years. No Problems.

[Tri-Z 250]

If the pump/vac line is off the action to the pump will not work....but do me a favor. Drain the oil out of the bottom end, check for grey milky oil. If it's grey you may be looking at a rebuild. You can and should use a spring style hose clamp on the line(like the ones on the carb). It don't take much to hold it in place. They grey oil will ultimately be from a failed rubber gasket in the water pump, which eventual causes head gasket to fail. What ever you do sort the issue before you run it...as a Z motor will run with a blown gasket/bad seal until it smokes the top end, or catastrophic motor failure(then it's too late). Sounds to me the steam from the water in the oil is causing back pressure inside the cases...it will find a release point eventually, that's when it blows up.