compresion 90lbs what should i do?

[twgranger]

I took my tri z to the yamaha shop to get the carb cleaned and they did a compresion check and it runnong 90lbs. They said it should be running 120-125lbs. they want like $750 to do watever it takes to fix it. The bike runs fine and fast. What should i do? will it hurt the bike if i keep riding it and why is it so much?

[J.D.]

They're full of trailprotrailprotrailprotrailpro. If you only had 90 psi of compression, I doubt it would start. Anybody wanna back me up on that? For sure, it would be REALLY hard to start. How easy does it start? And what they tell you of 120-125 psi, they're full of it. The correct PSI is 160-190 psi. I doubt it will hurt the bike to run it. 750 dollars to fix it is a ridiculous price. If you do it yourself you can do it for about 200 bucks.

81 dollars for piston kit(guy off ebay will sell to anybody), average 50 dollar bore price, 50 dollar gasket kit, 15 DOLLARS for a new wristpin bearing, thats a total of 196 dollars. Sure beats the shop ripping you off and any idiot can rebuild a 2-stroke, just make sure to drain the coolant first and torque down bolts to spex.

[twgranger]

they are cleaning the carb becuse it use to flood easy. but the bike has lots of power. i don't know what they mean it needs to be rebuilt. it runs fine for me besides the flooding.

[twgranger]

to do a compression check do you have to have the bike running?

[TRI-Zbrian]

you start the engine let it wrm up then shut it off and there is a tool with a gage that screws into the spark plug whole and u kik the engine over and it will tell you how much psi u have. you can also do it with the engine cold but u get a better eading with it warmed up first.

[twgranger]

but if they said it was only getting 90lbs of compression what would it run like? it runs fine for me.

[twgranger]

can i get that tool anywere? and how much? I want to check it myself. I think they are trying to rip me off $700.

[Dynofox]

If it only has low compression can't you just put a new pistion and rings in it? I guess unless it really needs a bore. twgranger the dealer is trying to rip you off hard core! If the bike runs fine and starts right up just ride it.

[twgranger]

Im going to see how it starts after they clean the carb. It use to start hard with it flooding so easy.

[bbechtel16]

can i get that tool anywere? and how much? I want to check it myself. I think they are trying to rip me off $700.

We bought one at Sears once. That's right we. Me and 2 of my friends went together on a $24 compression tester lol! I was disappointed to find they didn't include a small enough adaptor to make it work on the SX. But it does work on the 250R so I'd guess it would work on the Tri-Z too?

[TimSr]

Sign of low compression are , it will get progressively harder to start, youll start to lose low end power (top end will still seem fine), and your plugs will start to look like its running richer.

There is no way to know whether it needs just a hone and new rings, or if it needs a bore job, without taking the top end off and taking some cylinder measurements.

Beware anyone who quotes a repair price on something they have not disassembled. Houdini doesnt do mechanical work.

[slippy4]

yes, fleetfarm or any car place should have them. i highly doubt it would even run as my old YTM 125 had 90psi and it would shut off after about 10 min of riding ( normal for the 125 is about 135) My Z has about 175psi so 90psi would deff. not be able to start (at least not by kicking it over)

[TRI-Zbrian]

if it does need to be fixed this is how much it cost me here.

bore: 20$
piston and rings: 90$

gasket kit 15$

labor: free any person can rebuild a 2 smoke they are the easyest thing in the world.

thats a total of 125$$$ dont u dare pay 700 they are trying to rip you very badly even if they did the work its only like a 2 hore job, i could do it in an hour but i take my time and make shure its done right. thats fing highway robbery.

[200Xtreme]

If it only has 90psi , it would be hard, if not impossible to start! I also agree w Timsr in that it will lose it torque (low end), and it will run rich-be hard to start. I definatly wouldn't make the statement, that any idiot can rebuild a 2-stroke though.

[TimSr]

Yeah, Ive seen some two strokes that were rebuilt by idiots!

[wizzard]

i think before the compression dropped that low (if it really is supposed to be around 120 or higher) you would notice poor performance and excessive smoking. i bought a compression tester for a car engine at pep boys a long time ago, it fit my tecate but was too big for my 200x. a bike shop (another bike shop)should have something to fit your bike.