Trouble with a 15hp Johnson

[Dockside]

I have a 1983 15hp ran great and now it with runs for 3-4 seconds and shut off every pull? I can only start it at full throtle?

Pulled the carb, looks ok? fuel is good, got spark.....

Any ideas?

[Reelax]

Maybe a clogged carb jet?

[fishmaster176]

Did you rebuild the carb.? Sounds like it gets a little, but not enough to keep it running. Have you tried priming with a squirt can to keep it running? If it's an older engine, it could be having a fit on the ethanol. It raises hell with the inner parts of the old carbs. I have vintage snowmobiles and it's a nightmare to keep them running. Constant carb. cleaning and fuel pump issues. If the plugs are dry when it shuts down, then it needs more fuel. If they're soaked, the float(if it has one) may be stuck. Or the needle may be stuck.
Hope I haven't confused you more.
Good Luck.

[Gecha (Gerry)]

the description of your problem is definitely pointing to a lack of fuel.
Like others have mentioned, clogged jet would be #1 on my fix list.

[Captain Paul]

I have a couple of johnson motors and have had trouble with the gas tanks before drove me crazy trying to figure it out I would try anoyher tank and hose

[vtfishin]

I had a simliar issue earlier this summer, but mine ran a little longer...ended up being a fuel pump. With mine, if I raised the tank and or kept pumping the bulb every 5-10 minute I could keep it running...
After installing a new fuel pump it was night and day but I thought it was running a little rough and a tank of jet cleaner got me running smooth again.

[Dockside]

Jets are fine...changed lines......NO GO. Starts for 15 seconds then shuts down?

Buld is hard and pumping it does nothing?

Laid my 1978 25hp Johnson to rest last week. I don't think I can take another loss for team Johnson emtionaly


I do have 2 great running Mercury motors that are going strong! I guess I am "Back in Black".

[Reelax]

I would take carb cleaner and spray directly into intake while turning her over before you lay her to rest... If that don't work... try ether.... (Draggonballs says it gets him lots of buisness when I tell people to do that)

[dragnballs]

Matt,I said that it gets me a lot of buisness when it is done in efi's but with the age of Ben's engine it should be fine,vut I will say that if the fouling is due to the gel that is created when water and ethinol mix.... carb cleaner will not touch it but thanks for the plug buddy