omc engine struggles @ high speeds

[glasstream.]

I have a similar problem to a long string of OMC owners. I once could come out of the hole quick, and maintain high rpms. I've recently lost power on the full throttle. I do get some backfire when accellerating. My question is, would you check the fuel pump or the timing. It seems to run great in the driveway, and in nuetral.<br />Please advise...

 

[loadnet]

Re: omc engine struggles @ high speeds

I would do both starting with the timing advance.<br />Make sure it is advancing as it should be doing when under a load...<br /><br />After that <br />- check your fuel pressure to the carb.<br />- check for water in fuel.<br />- check the gas tank vent for spider webs clogging it up.<br />- check the little fitting on your fuel tank where the hose connects to make sure it is working correctly. It may be stuck half way shut.<br /><br />If it's sputtering at high rpm with an occasional backfire you could be running to lean which bad fuel or low fuel pressure (loss of fuel on demand) can cause.<br /><br />Bad timing advance can cause loss of power at high rpm and over fueling from not enough spark to the plugs under load.

 

[RonB1954]

Re: omc engine struggles @ high speeds

I had a similar problem with my omc engine and found after a lot of "trouble" shooting that it was the feed wire on the distributor. It was in bad shape and after striping and cleaning the wire my engine ran like new!<br />Hope this helps,<br />Ron