Hi all,
just thought i would post up an update to this thread. I have finally had a chance to fit the GMC pipe to my bike and give it a decent workout. The workout for the pipe was at round 1 of the Viper series at the Blue Rock track yesterday, for those of you that don`t know this track it is an awsome moto cross track and has a real need for horsepower.
I fitted the pipe during the week and am happy to say no mods required to fit the thing, a small amount of heat proof silicone around the joint to the barrel and to the muffler and not one leak to be found, you can place your hand over the muffler and stall the motor within seconds. No leaks.
Now the good bit, after practice i re-jetted only the main jet due to time restraints and i have a smile from ear to ear from the gains i have now got from the pipe. At the moment it is a little bit lazy out of tight corners but a quick flick on the clutch and it comes to life in a hurry, i am sure i can sort this out with a little more jetting and maybe a bit of gearing.
Out of the 5 races i did yesterday 3 resulted in a good holeshots to the first corner with a few good comments from some of the other guys, i have noticed a good improvement right across the power range and would say this is a strong 250 even against a fair few Pre 90 250`s which finished behind me.
So all in all thanks Geoff, this pipe has given the old beast a decent increase in grunt and a big thumbs up from me. I will give you a call in the next day or 2 and let you know what i have ended up doing with the jetting. Peter.
