86 SN 2001 - Low idle and eventual stalling

Hi All - I did a bunch of searching through existing threads but couldn't quite find one that matched my situation, so apologies if this is a common topic but I'm hoping it's a quick troubleshoot.

I spent an afternoon power washing my bilge to get rid of a ton of oil and grease that had accumulated. I tried to avoid engine components but spray may have hit some parts that it shouldn't have. My issue now is that the engine is idling very low, around 200-500 rpm, the tach 'bounces' off a low of 100-200 rpm up to about 500 rpm until it eventually stalls out after 20-30 seconds.

What are some of the common issues that would lead to this symptom? I've seen references to the anti-siphon valve, I've also seen people suggest issues with the carb. The engine has been running strong, idling well, and not giving me any issues for years, so it seems like I sprayed something I shouldnt have...

Thanks in advance.

I've found this works great: Dawn dish soap too.



Add some water to the bilge, go for a nice long ride so the mix sloshes around and drain. No spraying with the hose.

Turn the idle screw in a little. Works better if you hold throttle open or disconnect at carb. I always forget to put the quick connect back on at carb.

Actually, I have a quick update here. A neighbor who has way more experience than I do stopped by to look at the engine with me and he made a few adjustments:
- tightened the four bolts holding each of the two components on the sides of the carb (not sure what those are called)
- adjusted the two screws on either side of the carb (again, not sure what these are called)
- adjusted the idle screw

We were able to get the engine to idle nice and smooth at around 500-600 rpm after these adjustments, and I assumed we had resolved the issue, but when I took the boat out for a quick test ride the engine started to stall out and lose power around 3k rpm's, so it seems we may have fixed one issue and created another....

I'll probably pull my neighbor back over to take another look when I'm back at the lake this weekend.

Maybe spark plug wires got wet?

Tim,
Here's a youtube on setting a Holley idle mix

8122pbrainard wrote: Tim, Here's a youtube on setting a Holley idle mix

Really helpful, thanks!