2000 GTI compression

[spike97]

Mine reads both at 115psi. Is that way too low for how old it is? It has almost 160hrs on it

 

[Mickirig1]

Wooster as in Ohio? Sounds like it is a top end rebuild time. Not a real bad job or cost.

 

[mikidymac]

I would try a second quality compression gauge just to be sure.
1. Good strong battery.
2. Plug cables grounded.
3. Fuel off.
4. Hold throttle wide open while cranking.

 

[spike97]

Okay thanks guys

 

[spike97]

And do I need to have the other spark plug in the other cylinder while checking? I didnt think it affects it but I may be wrong

 

[Mike99]

Both plugs out. You want it to spin faster.

Mike

 

[spike97]

Will do thanks

 

[mikidymac]

Actually you want the one plug in.

THE ENGINE - 1) All accurate readings must be taken from a dead cold engine. A warm engine will yield slightly lower numbers. 2) The exhaust pipe and carburetor must be installed. The restrictions in the carb throat and the back pressures of the exhaust system can affect the readings. 3) Have a full charge on the battery. The speed that the engine is spun, has a significant affect on the indicated reading. 4) Leave a spark plug in the cylinder not being measured. Contrary to what you may think, the engine will turn over slightly faster with the opposing spark plug installed.

 

[spike97]

Thanks a lot for all the help mikidymac!

 

[spike97]

I re-checked compression and only got 118 psi now. But what I don't understand is, if my compression is actually that low then how come my ski starts up so well in the water and acts so powerful?

 

[benjilafouine]

Did you take a $200 (or more) tester? Last year I bought a tester at Carquest (our Autozone equivalent) that I thought was a good brand and it read my engine 20 PSI too low at 130. After not even 100 hours I was freaking out. Brought my ski to the local boat pro and it was at 150 with his pro tester. I only needed to change the plugs and give it 1/8th of a turn on the low speed screw because it was running a little lean. Make sure you have a proven and reliable tester before making decisions. 115 is too low that is true but if it was 135, it would still be usable for a while.

And follow mikidymac's instructions. He's good.

Benji.

 

[spike97]

I've just been renting the $40 autozone testers. And I did follow mikidymac's instructions and it got me 120

 

[benjilafouine]

This is not really good then. I'll let mikidymac respond. Question is: do a top end job before it breaks or use it until it breaks if it still runs? Everyone around here always say that a top end job is not worth it but since I am not a mechanics, can't tell.

Benji.

 

[benjilafouine]

Just one additional thing: having an engine breaking in the midst of July is no fun at all if you don't have a second sea-doo to fall back on. Happened to me and for one month I felt misery not being on the water...

Benji.

 

[spike97]

Yeah idk my ski performs so well that I have no clue if the compression tester is off. If it does as well as it does now only at 120 I can't imagine what it can do at 160. And I really hope that I don't need a rebuild but if I do then I'm just gonna run it til it dies

 

[mikidymac]

FYI, to the OP, try to keep one post as you have so many going at the moment they are all over the place.

If your ski runs that good I wouldn't get hung up on the compression thing. When it actually starts to drop below 120 it will get hard to start in the water.

 

[Mickirig1]

I would run it till it dies. We have such a short season I wait till winter to fix ski's.

 

[spike97]

Okay sorry for all the posts. I've just been making a new thread for the different problems ive been having and they've all led to the same convo

 

[WaveHound]

If you want some peace of mind, use your compression tester on a known healthy ski and see if it still reads low.