Buying a 1998 Speedster - Question about Compression of the engines

[MidnightR6]

Hi,

I am new to the forum and I am looking into buying a 1998 Speedster with twin 110 hp engines. The previous owner says "Had a compression test done last year the left engine has lost 2 hp from factory the other checks out perfect no power loss". When I went and looked at the boat, he said that when you take-off, the left rpm guage lags behind a little bit and then eventually matches the right engine rpms shown on the guages.

Do I have anything to worry about? I have read a little on compression checks, but is the fact that the LH motor is indicating that it is starting to lose power a big problem that will eventually lead to having to rebuild the motor?

Thanks so much!

I look forward to being a fellow Sea-Doo owner!

 

[RFoster130]

Do a compression test and water test it. If there is a problem you should notice it. Compression should be 135-150 with both engines being within 10% of each other. On mine the 2 are off a little when comparing the RPM gauges. At WOT though they are the same.

 

[MidnightR6]

Thanks for the quick response!

I am relatively mechanically inclined. Is a compression check something that I could easily do myself? Or should I have the boat taken to a mechanic before buying it? What kind of tools/process is involved?

 

[MidnightR6]

And... The Seller has agreed to water test the boat. Will I be able to tell if something is obviously wrong during that test because it is twin engine, and I think you would be able to tell pretty easily if one engine is acting up.

So should I still compression check it if it seems fine in the water test?

Thanks!

 

[BMANN06]

Could be fuel delivery, or slack in throttle cable ..

I agree with foster, 110% do a compression test. You can get a decent gauge at autozone for like 25 bones. Can stress how important this is on these boats. You don't want to end up in the same "boat" (err uhh yah) as me and dsw222 where you end up losing a motor or 2 in your first month.

That aside, each engine has it's own carb, and throttle linkage. This could be why your finding differences in the performance of each engine. If you get the premium membership you can download the manual for your boat and the carb guide aswell. In the manual there is very detailed instructions on setting the low speed screw as well as syncing your engines via cable adjustments.

I have this boat as well and can tell you that it is one hell of a fun boat to own. There's nothing quite like going into a full 90 degree drift across the water with 4 ppl in your boat at 60mph!!

Good luck and happy new year!!

 

[RFoster130]

Yeah its very easy to check the compression. Most auto zones even loan them out with their loan a tool program. I would do that and water test for sure. When you take it out though, try to stay out for a while. A quick 5 minute run wont show everything. Let the boat get up to full temp and run it hard a few times. If there is a problem, you will be able to tell.