Mercruiser 170 back pressure thru valve cover vent ??

[tinydog]

Just purchased a Wellcraft American 190 thats been sitting for a while and this is my 1st inboard. Motor starts and runs good on the muffs but there is a fair amount of constant pressure at the vent from the valve cover to the flame arrestor and Im just wondering if its normal to have some pressure there. thanks.

 

[Technorunner]

Re: Mercruiser 170 back pressure thru valve cover vent ??

it should be coming some vapors when the engine is warm. But you shoudent have any pressure there. if it has benn sitting it can be compression rings that have been stuck. Try and do a compression test and se if you get some bad readings there

 

[Don S]

Re: Mercruiser 170 back pressure thru valve cover vent ??

The 470 seem to always have a lot more pressure out that vent than most engines. Without seeing it, it's hard to tell if it's too much or about normal.

 

[riptorn]

Re: Mercruiser 170 back pressure thru valve cover vent ??

Any pictures?