2000 Johnson 130HP Stalling/Mis-fire at low speed

[VanillaGorilla]

Hey guys. I recently got my boat back from the shop where the starter motor was being rebuilt. I took the boat out and have been having problems with it stalling at idle speed and misfiring even when I'm running at 1200-1400 RPM. Seems like it is starving for fuel (even when it starts to stall and I hit the throttle, it still stalls out). But it hauls just fine when running wide open. Maybe it is just a coincidence, but I'm wondering why this is happening after just getting it back from the shop. I have a call in to the mechanic to see if any other settings were changed on the engine when they were testing the starter. I'm also thinking maybe I have a fouled plug or if they shut off the fuel during testing, maybe a vapor-lock situation. Any thoughts???

 

[dolluper]

Re: 2000 Johnson 130HP Stalling/Mis-fire at low speed

check your battery and that all your connections on starter and battery are clean and tight then check plugs wires coils fuel leaks

 

[VanillaGorilla]

Re: 2000 Johnson 130HP Stalling/Mis-fire at low speed

Checked into it more, bought a shop manual as well. Not sure what to tackle first. The shop said all they did was adjust the throttle back to 700 RPM because it had been running at 900. I adjusted it back to 900 for the hell of it ... and still have the problem. I'm thinking I should replace the spark plugs, and if that doesn't fix it, start troubleshooting the fuel system. Question for you guys though ... if I run wide-open just fine and then have this problem at idle (doesn't matter what gear), if it were fuel, wouldn't I have the problem at high speed too? Just wondering if the fuel system is vapor locked. Thanks guys!

 

[zipp]

Re: 2000 Johnson 130HP Stalling/Mis-fire at low speed

Don't take my word for it (because I'm certainly no expert) but it sounds to me like a sign of poor compression. Maybe a sticky ring or a cylinder that's carboned up.

 

[Dhadley]

Re: 2000 Johnson 130HP Stalling/Mis-fire at low speed

When it starts to stall, what happens if you tap the primer?

 

[reeldutch]

Re: 2000 Johnson 130HP Stalling/Mis-fire at low speed

a compression check is always good to see if there are problems.<br />but if you have low compression you are to late.<br />just check the compression to be sure.<br /><br />what i think you have is dirty idle jets in the carburetor.or a stuck needle.<br />you realy have to make shore your not running lean. running lean means not enough gas in the air gas mixture and that means not enough oil to lubricate all the moving parts. <br />check the sparkplugs for dry plugs.<br />so you can figure out which carb it is.<br /><br />- first:<br /><br />- do a comp check<br />- if compression is good clean carbs<br />- check for engine operating temp (tstats)<br />- check circulation lines are well connected<br />- check for air leaks<br />-if all is well do a good decarb and recheck compression.<br /><br />these are just thougts that come up with me there might be more to check out.<br /><br />good luck<br />reeldutch