compression question

[bartdjunkman]

is it possible for a boat to run at 60 mile an hour and pur like a kitten and have compression issues. Idles a little rough, the longer it runs the better it does on idle. May need adjusting. I was having some stater issues last year and some people were telling me my starter was kicking out because of low compression. I was just wondering about the compression was problem was possibe if able to run at high speeds so smoothly.

 

[JB]

Re: compression question

Remotely possible but not likely. Do a Link 'n' Synch by the book.

 

[bartdjunkman]

Re: compression question

link and sink? what is this exactly? Thanks again for the help.

 

[emdsapmgr]

Re: compression question

Rough idling may be due to the tiny idle passages in the carbs being clogged with dried fuel, dirt. When your engine idles, the carb butterflys are closed, so the engine gets it's fuel from the special idle circuits in the carb bodies. These are pretty small and it is not uncommon that these accumlate dirt, debris in them-then they don't idle well. A good cleaning with an aerosol carb cleaner may be all you need to do. This will have no effect on full speed running.

 

[GeneH]

Re: compression question

Since you seem to be concerned about compression, why not test it to see what you have? This ought to be a normal part of maintenance anyway.

 

[tashasdaddy]

Re: compression question

i agree with all the above. linc n sinc, is a step by step synchronization, for the spark timing, and the carboration of the motor. it is only cover in the OEM serivce manual.

what motor do you have?

 

[bartdjunkman]

Re: compression question

Thanks guys i think i will have compression checked and while they are at it have them check out the carbs. Spring fishing is coming soon cant have a dirty carb keeping me from catching some paper mouths.

 

[bartdjunkman]

Re: compression question

took my boat by the dealer today and he told me that he would run a compression test first. He also told me that these xp150s were notorius for sucking air around the block. He told me it would sound like sneezing in the warm up period and then the idle would still not be good. He told me he can tell when he puts it in the tank. 6 to 8 hours labor to tear down and reseal. does that sound like anything you all have heard of or seen?

 

[trx88]

Re: compression question

i dont know anything about the xp150 but i would get a second opinion

you can buy a compression guage for 30 bucks at a parts store

and if you pull the plug wires it wont start so you dont need a tank

 

[emdsapmgr]

Re: compression question

It's uncommon (but not unheard of) for the crankcase to leak at the crankcase halves. You can easily test for leakage between the case halves. I would support a second opinion if the powerhead is diagnosed as a leak between the case halves-requiring teardown and reseal. Lean sneezes through the carbs are common after cold starts and during warmup-a different issue than a crankcase leak. After initial cold starting, you should occasionally push in on the ignition key to provide extra fuel for a second or two. You may have to repeat this till the engine warms up and idles on it's own. You can usually rent a compression tester at a local auto parts store.