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FJR Motorcycle Forums
Technical & Mechanical Problems
Misfire at steady cruise
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<blockquote data-quote="ionbeam" data-source="post: 990367" data-attributes="member: 277"><p>If you got those readings with a fully charged battery, hot engine and holding the throttle open while cranking you have an issue.</p><p></p><p>It could be as simple as sticking rings. Put a tablespoon or so of oil in each cylinder as you run the compression test. If the compression goes up it's rings, if it doesn't it could be carbon on the valve seats. I seriously doubt that all cylinders would have equal carbon.</p><p></p><p>I would suspect the test and not the engine, after all, you say it has good power and it *<em>sure wouldn't</em>* if you were down ~40% of your compression. Verify the o-ring on the compression tester and redo meeting the conditions in the opening sentence. Put the battery on a trickle charger overnight to ensure that you have sufficient cranking speed.</p><p></p><p>Before going after major internal issues you may want to take your injectors to a diesel engine shop and have them flow checked and balanced.</p><p></p><p>Take a couple of minutes and read <a href="https://www.fjrforum.com/forum//index.php?showtopic=104414&view=findpost&p=420190" target="_blank">this</a>, I see you using several different descriptions of what you are feeling.</p></blockquote><p></p>
[QUOTE="ionbeam, post: 990367, member: 277"] If you got those readings with a fully charged battery, hot engine and holding the throttle open while cranking you have an issue. It could be as simple as sticking rings. Put a tablespoon or so of oil in each cylinder as you run the compression test. If the compression goes up it's rings, if it doesn't it could be carbon on the valve seats. I seriously doubt that all cylinders would have equal carbon. I would suspect the test and not the engine, after all, you say it has good power and it *[I]sure wouldn't[/I]* if you were down ~40% of your compression. Verify the o-ring on the compression tester and redo meeting the conditions in the opening sentence. Put the battery on a trickle charger overnight to ensure that you have sufficient cranking speed. Before going after major internal issues you may want to take your injectors to a diesel engine shop and have them flow checked and balanced. Take a couple of minutes and read [URL="https://www.fjrforum.com/forum//index.php?showtopic=104414&view=findpost&p=420190"]this[/URL], I see you using several different descriptions of what you are feeling. [/QUOTE]
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FJR Motorcycle Forums
Technical & Mechanical Problems
Misfire at steady cruise
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