1999 Johnson 25hp very bad idling problem

[Michael leblanc]

I'll mess with in the morning and get back with yall

 

[racerone]

The black plugs are a concern.----Is there a thermostat installed ?-----Is it working ?-----Is the motor warming up at idle ?-----Only by answering these simple questions can you find the issue with this motor.-----Sometimes it seems owners do not want to answer questions.----Hard to pinpoint stuff from say 1000 miles away !

 

[Michael leblanc]

Thermostat is working it got hot on me twice a while back but it was at wot it stop pissing cause motor was to high out the water but I fix that ...and about 2 weeks ago I had a older 25hp Johnson carb on it for one day cause a piece broke on my carb and I had to go run my nets and that carb was running rich so I'm thinking that's where the foiled plugs came from cause it was smoking bad when I went I had the needle turned out a lot so it would run cause it was missing some caskets around the lean/rich screw so I'm thinking that's were that problem came from .....and another thing while it was running I touch top plug wire and it shock the hell out of me ...lol I read on here somewhere people said it shouldn't shock you and some say it's normal ?

 

[Michael leblanc]

No Title

And another think a while back I turn this screw in trying to link/sync and I think I did it right but I'm not 100% sure when I throttle all the way down the little roller that touches the cam lines right in between The two marks

 

[racerone]

That screw is the idle stop.---Prevents motor from inconvenient stalling.-----The stop collar on the wire rod normally has less than 1/4" gap at idle.-----I believe there are issues with condition of your motor.---Later today I can post questions for you to answer.--Sometimes it is frustrating when folks do not answer clearly.

 

[Michael leblanc]

K thanks ..I think it's something with carb or linkage setting cause only at idle it spits and motor jumps and it takes off fine and runs awesome mid to wot pushes the hell out of my boat a lot of power

 

[racerone]

???----You waited till post # 23 to add that the motor overheated and twice for that matter !--Has impeller been replaced ?---So what inspections were done to see if any damage occurred.---Have you checked head bolt torque ?----Checked compression ?---Saying that the motor runs great at full throttle does not mean that there is no damage.

 

[Michael leblanc]

I can check compression and let y'all know

 

[Michael leblanc]

100 on both cylinders

 

[Michael leblanc]

I know a good bit about Johnson outboards just getting confused about my idle I know if the motor is sneezing and skipping at idle it's running to lean and I have to back out mixture screw 1/8 turns till I find smooth idle but then it starts smoking and foils out the plugs so I'm confused about that everything is fine but idle maybe I can soak carb overnight in carb cleaner and then blow out with a air compressor ..I have never soaked it before but I cleaned it with carb cleaner and blew out all passages but maybe just maybe it didn't clean it out completely but air did come out all other ends when blew it out

 

[oldboat1]

It seems counterintuitive, but lean it out until rpms increase, then lower throttle setting and lean it some more. If it stalls, back it out. If you can't dial it in, it could be a carb blockage like you suggest. Rigorous cleaning requires disassembly and soaking, then spraying with carb cleaner and maybe compressed air. If you did not remove the domed plug up at the top, you should do that and clean the idle passages under there -- need a kit for the replacement expansion plug, although I've patched and reused them using epoxy.

And it's possible you are not getting a "lean sneeze", but running rich (stumbling). If backfiring through the carb, there might be a problem with the reeds, but not very common.

[ed. With poss. exception of the h.s. orifice, can use soft wire to clean all openings -- that and spray cleaner.]

 

[Michael leblanc]

I replace that plug last year on top of carb but did not seal it with anything is there a chance is leaking air there is why it's sneezing and if so can I just cover it with epoxy

 

[oldboat1]

Can seal it -- some use finger nail polish. Tapping it down and expanding it is usually enough. When I refer to epoxy, I mean a time or two when I reused an old one, patching a hole created when I pried it out -- best to use a new one, like you did.

If it's really lean sneezing, you should be able to correct it by setting the needle slightly richer (counterclockwise). When you initially adjust, you want to get it as lean as you can (clockwise) without stalling.

 

[Michael leblanc]

Yes I hit it in the middle of plug with a flat punch just enough to expand it ...I guess I'll get new plugs then go from there might be all it is cause they are black

 

[oldboat1]

could be the carb mounting gasket. could be a head gasket (overheating hist.) Should be able to dial it in.

 

[Michael leblanc]

Ok I changed spark plugs and I gap them to 30 thousands and I started it on the muffs and it ran fine but only ran it for 5 minutes didn't have that much time after work ....I'm going to test it in the water Saturday when I got check my hoop nets

 

[Michael leblanc]

On ran it yesterday still did it but not bad so I open needle up some more and it slowed down a lil but it started smoking a lil bit so I'm not sure what it's doing unless I'm sucking air from my primer pump system somehow