99 Johnson V-4 90 hp 60 degree

[rrhillard]

Mod # is J 90PLEEB. Its running really rough. Lack of power. Stalls out at low RPMs. I drained all the gas out of the tank and its on its 3rd full fresh tank. Compression is 90 on all 4 cylinders. Its using oil regualary. Changed plugs twice since January. First set were the cross referance version of NGK and now the Champions that the book calls for. Did a spark test and it hits out to atleast 7/16 of an inch. I did the above stuff from reading other postings. I am new to having boats. This one only about a year and a half. Dude I got it from just let it set, but at first it ran fine. I dont want to get ripped of at a shop but dont want to rebuild all 4 carbs. Kinda thinking tarnish in the bowlsand jets. I know my way around a car, atv, lawnmower, and such, but need some help on this stuff.

Thanks

Gunnery Sergeant Ryan Hillard USMC

 

[tashasdaddy]

Re: 99 Johnson V-4 90 hp 60 degree

sounds exactly you are on the right track. but a carb cleaning and rebuild is in your future. these are basic steps, but your carbs are a little more complicated.

 

[Dhadley]

Re: 99 Johnson V-4 90 hp 60 degree

Just keep in mind that each carb not only delivers gas to each cylinder but delivers oil too. If there's enough trash / varnish to disrupt fuel flow, it's disrupting oil flow too. Pistons don't like that.

 

[rrhillard]

Re: 99 Johnson V-4 90 hp 60 degree

PART TWO.
I cant sit still until its fixed or broke.
I put a can of SEA FOAM in it. No joy but it will more than likely take a little while. While it was running I sprayed a little Synthetic throttle body cleaner in 1 carb at a time. All did the same ... nothing... excert the top left side. Moter reved up a little on each spray.

Thanks for the quick posts. When you say rebuild, are you talking all 4 carbs or the entire motor. Also where do I find the water pump to check it.


Once again Thanks.

Gunny

 

[JoLin]

Re: 99 Johnson V-4 90 hp 60 degree

The water pump is in the lower unit. It isn't a particularly hard job to do, but really tough without a step-by-step repair manual. A factory manual (reprint)can probably be obtained through a dealer as your motor is not that old. Otherwise, eBay. I'm also new to outboards and I have obtained 4 reference sources:

A Seloc manual (it's like Chilton's for outboards)
A factory repair manual
A parts catalog for your motor (invaluable for seeing how things fit together)
A factory owner's manual (the shop manuals are great, but the owner's manual tells you a lot about how to use the blasted thing).

 

[HighTrim]

Re: 99 Johnson V-4 90 hp 60 degree

When he said rebuild, he was referring to the carbs.

When you order your manual, get a factory OEM Service Manual, it will pay for itself the first time you do your carbs. Then it will pay for itself many times over once you tackle your impeller.

The following videos may be of assistance to you, good luck.

CARB REBUILD:

http://www.meegsonline.com/tmd/TMDsVideoChronicle2.wmv

WATER PUMP:

http://www.meegsonline.com/tmd/waterpump.wmv

www.themarinedoctor.com/videos/removecase.wmv

www.themarinedoctor.com/waterpump.wmv

BTW, spraying carb cleaner into the throat carbs is not cleaning them. They need to be completely removed, soaked in a bathing bucket, cleaned, and blown out with compressed air. If you do not have a compressor, there are aerosol cans that will work in a pinch. Be sure to thoroughally clean all jets/orifices. The seafoam will help, after you clean the carbs. Use it as a fuel additive, along with an annual decarb.