Hi

I have been lurking around here for sometime and i have learned alot about clutchs.
I have a sand drag quad with mach z triple (780) and a TRA clutch.
After runing about 10 runs in a 100 yard drag strip i lost my MPH from 84-86 down to 76-78mph. The bike luanchs the same from stand still but half way through it doesnt pull as hard as it use to.
Checked the engine and every thing seems to be within specs. So the only thing left is the clutch.
My quastion is where should i start trouple shooting???
So far i replaced the belt with no help.
Any help will be appricaited

Thanks

Rayed
Saudi Arabia

I would like to know the compression of the engine.

Cold engine, start and let run for 5 seconds. Shut engine off and take a compression check on each cylinder with 8 pulls using wide open throttle.

When you have done a few more runs and start to notice that mph is dropping off. Take another compression check with same procedure.

What is cold compression value on cylinders?
What is warm compression values on cylinders?

1] I would like to know what kind of fitness that your pistons/rings are in.
2]I would love to see a picture of your vehicle. :)

Regards
Joey

Yes do all of the above, but also when was the last time you were inside your clutches? You might want to check the primary and the secondary for there are a couple different things that could be causing this inside the clutches.

Oh and also, this same thing was happening to my 670. It would launch hard and then around 40mph or so and then my rpm's would drop a little and the rest of the pull would be weaker than normal and i would never reach the rpm's i used to... I looked at the compression, clutches, everything and nothing seemed to work. So i took it down to Roger's Sport Center and they replaced the "computer" i forgot its actual term, He said that these were the symptoms of it going bad. I have to go pick up the sled soon and im pretty certain this should fix it. Just something else you may want to look into

And welcome! I'd be willing to bet you are our first member from Saudi Arabia!

(I agree- i wanna see pics!)

Thanks guys for the quick answers.....
Joe: The comp was about 165 cold when i got the bike from the US (pre owned), right now it is 165 cold. I didnt do a warm pressure check.
The bike lost the speed after about 10 runs from the time i got it. I have done after that about another 15 runs with same slow mph. I never got back to the old MPH and the times it use to do. So some damage is done somwhere.
The engine is drag ported, got 40mm lectron carbs, V3 reeds, and jaws pipes.
I run it on c14 fuel with k2 oil.
670x: I didnt open the clutchs at all and it will be my first time that is why i want to make sure that am looking at the right thing. The primery has a thunder shift kit on it.
Joezr: am sure i am.............thanks

im in love! that rocket looks fawking kewl man!!!! :)

Check psi values to eliminate that as a problem. Need engine to run consistant first before can analyze clutching. Chasing a worn engine by clutching = DOSE !
Engine first...check clutching next.

Ya you right......i will check again but after a month or so am going offshore now to dig some hole :bash:
Thanks for the help man :)

Please excuse my French, but that thing is F!cking awesome. :devil: I bet that is one fun ride. Good luck with everything.

some b--ch,that looks cool

you should be hanging out at this forum....

http://z9.invisionfree.com/Dragsters_Funny...hp?showforum=17 (http://z9.invisionfree.com/Dragsters_FunnyCars/index.php?showforum=17)

Dragsters Funnycars->Sand Dragsters and Funnycars->Sand DragRacing