I've been having a problem with getting my engine to idle. The boat has been sitting for about a year or more...so i cleaned out the tank, an carbs and replaced the filters. A friend of mine (good with boats) came over and got it running smooth... idled and all. but i tried to take it to the lake about 6 hours later and it wouldn't idle again. only way to keep it running is to give it some throttle. Then it runs ok but is kind of erratic, it revs up aliitle every once in awhile (every 60 seconds or so).

What do ya'll think this is?
Vaccuum line maybe?
or idle just needs adjusted again?
I'll pick up some sea foam today, and see if it hepls any.

Thanks, John

I would bet you that your MOTOR runs like [censored] on Ethanol gas?

Could be several things in no particular order:

1. Gas tank vent, but probably not.
2. Carbs still not clean or mis-adjusted. ( my guess is this one)
3. Needs new spark plugs
4. Low compression in one cylinder.
5. Fuel line is leaking somewhere. When it idles UP for no apparent reason, it may be running lean during that time...starving for gas.
6. Check the timing.

I'm not a professional mechanic by any means, but I'd look to the carbs and fuel lines first. Hope this helps.

Sounds like you have a cylinder or two misfiring. That motor will idle all day on 3 cylinders and sound good doing it, until you put a load on it.

You can't set the idle with the engine running on muffs, it has to be done with the lower unit submerged.

First do a compression test -- no sense spending time & money on a motor with bad compression.

Then a spark test -- set your tester at 7/16" and look for a sharp blue spark. All plugs should be removed and leads grounded to the block.

If by cleaning the carbs you meant anything other than disassembly, soaking overnight in carb cleaner, blowing out passages with compressed air (or aerosol carb cleaner), and reassembly with new carb kits (gaskets, o-rings, float valves and seats), then they're still dirty.

Did you set the float height according to the manual?
Did you use new carb mounting gaskets?

Did you link & sync after working on the carbs?

What spark plugs are you running and what do they look like after idling?

I started it today and did a little adjusting on it. I got it idling and got it put in gear fine.

It was like this the other day but when I took it to the lake and tried to start it while backed in (lower unit submerged) it wouldn't work.

JTexas... I didn't see your post until after i adjusted the idle (with muffs)... I don't know the compression and don't have a gauge... so I guess thats my next plan.

all gas hoses and vent hoses are good, and the plugs are brand new, and I'm getting a good spark.

I had a Johnson V4-130 that had that problem.It was some excess gas drain plugs, in the carbs. Took them out and replaced them and it idled like it was supposed to..

Compression check first for sure. Auto Zone has a cheap comp tester, it takes about 5 minutes to check the comp. They should be around 125-130 lbs per cylinder.Is this a VRO setup?