BF90 has a wierd Vacuum problem.

[kc90]

Hi...i'm new to the board and I have a problem with BF90(1999). When I start the engine and its cold it idle ruff, hic-ups and studders when reved up. It has also had bad fuel consumption.<br /><br />When I took a vacuum reading at the intake, it drifted between 10 and 20 inches of mg. (this was the same at every carb). This all started this season.<br /><br />I have replaced the spark plugs and changed all the fuel filters. I have also cleaned the carbs, reset the pilot screws, replaced the intake gasket etc. Also i did a compresson test and all the cylinders are equal. I've tested for vacuum leaks with my tester and have found zero.<br /><br />I'm starting to think this is a ignition problem. My question is has anyone had this problem before? <br /><br />Any input would be great.<br /><br />thanks KC

 

[dobers]

Re: BF90 has a wierd Vacuum problem.

we have had this problem in the shop before it seems to me bad fuel was the problem you should try draining the carbs and running the engine on known good fuel not what is in your tank <br /> the engine we had in at the shop the fuel looked great but it smelled a little funny long story short it cleared right up