2001 Trailblazer, did my research, just a few questions

[J_Watson]

I knew this wasnt going to be a power house type of quad, but its barely faster then my buddies honda 350 fourtrax!

I was looking into a new pipe and have been reading that HPD makes the best one for our 250's (7-8 hp increase)

Questions:

- HPD says you need to a run a clutch kit with their pipe? Is this true and why?

- With a UNI-Filter and pipe will the carb need re-jetting? also, will it need re-jetting with just an air filter?

- Is 91 octane fuel beneficial in a stock engine or should i save my money and stick with 87? How much would need to be milled off the head to get the most out of running 91?

- Is Polaris synthetic blend 2 stroke oil good enough or would i notice and improvment if i switched to Amzoil Interceptor oil?

I think thats all for now.

Thanks,
Jeff

[blueline15]

These are my opinions.

1)Typically not. Although clutch kits can be put in at any time. Usually people put in clutch kits when they get bigger tires to re-gain the bottom end they lose from the heavier tires. My guess is that the clutch kit is set up with the proper weights and springs to take advantage of the motor spooling up faster with new exhaust. That is my guess.

2)With a pipe and a UNI, yes very likely the carb will need to be rejetted otherwise it will probably be slower then before the pipe. With just a UNI, you probably do not need to rejet. Its impossible to say, really depends on elevation and temperature where the jetting should be.

3)With a stock motor, 91 will do nothing to help, it may actually hurt the performance since it resists detonation, it may ignite too late in the cylinder, and you miss the sweet spot for power. On a stock motor I would stick with 87 octane. I am not technician so I cant answer the question about the head for you, but I believe you have to do more then just that to get the compression up enough take advantage of 91 octane, including a new high compression piston.

4) I have never noticed any kind of improvement with two stroke oil. With that said, the polaris oil is fine. I am sure the amsoil would be too. I would just run a brand name oil. I know there is "racing" oil, but its main job is to just protect the engine, not provide improvement gains, so I say just run what you like.

[Bruce!]

Welcome to the boards!

[J_Watson]

I dont think 91 could HURT a motor, but i can see it being a waste of time.

Maybe someone else will chime in and give their opinion