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Just looking to find out what the compression should be at or near for this motor. I was told by a marine dealer that the reason i am not running top speed is that i may have lost a cylinder. Was gonna do a compression test to start with.
Thanks
Matt
225 is between 100 and 110. Should be no more than 15% difference in all cylinders. Warm the motor then pull kill switch all plugs and open butterflies wide open to do test.
Richard
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kllr bee »</TD></TR><TR><TD CLASS="quote">225 is between 100 and 110. Should be no more than 15% difference in all cylinders. Warm the motor then pull kill switch all plugs and open butterflies wide open to do test.
Richard</TD></TR></TABLE>
+1 http://xs-s.com/zf/images/smile/emthup.gif
If the compression checks out ok, move on to a "Spark Test" on ALL SIX CYLINDERS. http://www.bassboatcentral.com/smileys/wink.gif
Appriciate the info fellas, I assume by spark test is to change the plugs or check for spark by pulling one out at a time and grounding and checking for spark?
Am i in the right ball park?
Another thing if i would have dropped a cylinder would i still be making 57-5800 rpms at WOT?
The engine does smoke alittle when started but when warm no smoke at all. When I'm running no cutting out or missing can be heard. I will start with the small and work to the bigger things.
Thanks again
Matt
"Spark test" refers to connecting all spark plug wires to a "spark tester" and spinning the engine over to watch for spark.
An alternative is to utilize a timing light.... clip the inductive pickup to each plug wire (one at a time) to make sure the light is "flashing" (less desirable, but acceptable method).
If you're at 5700-5800 RPM's.... you may have a setup, prop, or hull issue at the root of your issue, however. Very difficult to make that RPM range with a cylinder down "completely". http://www.bassboatcentral.com/smileys/wink.gif
Still recommend checking..... http://xs-s.com/zf/images/smile/emthup.gif