200hp johnson venom problems

[diggs]

i have a 200hp johnson venom on a javelin 409 f/s Takes a long time to start and once started hard to keep running. After about 15 minutes runs ok. Then after stopping to fish or sit for 3 minutes or up to an hour starts for 5 seconds then dies. Have had 3 different shops check it out in the last four years. They all say everything checks out fine but stills runs poorly. Plugs seem to get oil on them quite quickly. At a lost love boat don't know what to do First time out this year lost 500rpm somehow to but have good compression, any help would be great

 

[Solittle]

Re: 200hp johnson venom problems

Welcome diggs - Lots of info here if you haven't already found that out. <br /><br />To get the ball rolling please post the model number of your engine. Also do you have the shop manual for your engine - OMC preferred?<br /><br />Start by checking for spark at each cylinder. The spark should be able to jump a 1/2" gap with a bright blue snap. If you have lost 500 rpm I would suspect that you have dropped a cyl.<br /><br />Also what is your rpm at wide open throttle? And while we are at it what is the compression reading for each cyl?

 

[diggs]

Re: 200hp johnson venom problems

Thanks SoLittle for replying<br />The model # is j200stledm and i just ordered a shop manual for it. My rpms were 5600 at wot and the end of last season. First time out this year I could not get it over 5000 rpms Had it tuned up 2 weeks ago and the mechanic said the compression was #1-100, #2-100, #3-98, #4-98, #5-100, #6-100. I was told that was good for my boat. he checked the spark and also told me that was good, but i did not see it so i am taking his word for it.

 

[diggs]

Re: 200hp johnson venom problems

Does anyone in the chicagoland area highly recommend a shop that is willing to water test my boat. Any input on that would be great. <br />BTW great site and thanks for responses