78 johnson 9.9 not running right.

after cleaning the carb out (4 times!) i finally got this old engine running ok..then after a bit it slowly died.
i took it apart again and noticed the main jet has an outer tube and an inner jet..the outer one was way bent up as if someone had tried to get it out and mangled it. i carefully pried it away from the edge so it looked almost perfect..but not smooth. after trying it again it ran much better..but then after a couple of minutes it acted like it was out of fuel and started to die..revving it up barely got it going..but it would die again quickly.
i had taken apart the fuel pump and clean debri out of the fuel tank etc..noticed the gasket is getting cracked on the edge but it seems ok next to the seating surface. i know this fuel pump is not rebuildable..don't really want to spend the dough on one if i don't have to..i have replaced two pumps on other engines in the past to find they were not really bad.
the funny thing is at one point the motor started running faster like it had an air leak. i tested it by spraying carb cleaner around it and as i expected the only place that seemed to make it change rpm's was around the throttle linkage.
the gasket's seem to be ok.
the float is ugly as heck but not leaking.when i first started on this project i kept getting dirt in the carb and it would only run at high r.p.m...now that is solved but it seems i have to turn up the low speed from 1 1/2 turns to more like 2 1/2. it seems that after it runs for a couple minutes and dies if i let it sit and restart it after a bit it will run ok again for a couple of minutes..i did notice when it started slowing down twice i could hit the primer bulb and it sped up a little..but then died in a few seconds anyway.
i am wondering if the float could be the problem?
when i pulled the bowl it looked pretty full..but i dont know the specs on this carb..it might be off.
this has not seemed clear to me what the symptoms are..they dont seem to be consistant.
i could use some help on this before i start throwing tons of parts into it..i am thinking of getting a used carb off of e bay but they want too much for an untested carb.normally i would get a kit for it..but that high speed jet seems like it could be an issue and i dont have a tool to remove it..might look into getting one though.
thanks!
thanks.

Re: 78 johnson 9.9 not running right.

Here's a cheap ebay carb:
http://www.ebay.com/itm/EVINRUDE-JO..._Accessories_Gear&hash=item25769ca249&vxp=mtr

Looks like it needs a cam follower but just use your existing one.

Re: 78 johnson 9.9 not running right.

you may be losing spark as well...I'd check to be certain once the engine quits

Re: 78 johnson 9.9 not running right.

AlTn said:

you may be losing spark as well...I'd check to be certain once the engine quits

Click to expand...

it slowly dies.like it runs out of fuel. when it is doing that i have removed the carb and usually it seems to have plenty of fuel in it..but a couple of times it has seemed lower on fuel.
thanks for the input.

Re: 78 johnson 9.9 not running right.

You can elevate the tank above the engine and it will gravity feed the carb. If she runs right it will likely mean a new pump. Pay close attention to any possible air/fuel leaks as they will give you about the same symptom. Have you put a new needle and seat in your carb.? I would do the float at the same time. Might be worth while when you have it apart for cleaning. The fact that you pumped the primer and it only sped up momentarily makes me think it's not the pump as the carb. full should run a few minutes at idle before it's empty enough to stall. Best of luck. Rick.

Re: 78 johnson 9.9 not running right.

Rick. said:

You can elevate the tank above the engine and it will gravity feed the carb. If she runs right it will likely mean a new pump. Pay close attention to any possible air/fuel leaks as they will give you about the same symptom. Have you put a new needle and seat in your carb.? I would do the float at the same time. Might be worth while when you have it apart for cleaning. The fact that you pumped the primer and it only sped up momentarily makes me think it's not the pump as the carb. full should run a few minutes at idle before it's empty enough to stall. Best of luck. Rick.

Click to expand...

thats a good Idea Rick..i will try that with the tank. i have the feeling it is the carb..but not sure that is the entire problem.
the other thing that makes me perplexed is that after i took off the carb when it died the carb had plenty of fuel in it.
as to air fuel leaks,as i stated before i squirted the entire fuel system down to check for r.p.m. change and the only place that made any difference was around the throttle plate where it goes through the carb..that is normal.
thanks for the suggestions.

Re: 78 johnson 9.9 not running right.

i won the bid on that carb on e bay..32 bucks plus shipping..
i will post results when i get it and see if that is the only issue..i did order the gasket that was in somewhat poor shape in the fuel pump as well.