90 Hp Johnson losing prime, stalls after 5-10 minutes at low idle

[dhickey]

YES.

Or fuel pump.?

Was that checked?

[Doctrt]

Brand new plugs. A bit black, but fouled? I don't know. You be the judge.

[Ainsley]

What oil and gas are you using?

[Doctrt]

YES.

Or fuel pump.?

Was that checked?

And yes, new fuel pump.

[DRIFTER_016]

They do look a little fouled.

Has it been run only @ idle or have you run it mid to high throttle?

It could be a flooding issue if the float is stuck or you have varnish built up on the needle and seat.

 

Have you run any Seafoam through it?

[Doctrt]

What oil and gas are you using?

TCW-3 and Shell V-Power.

[Doctrt]

They do look a little fouled.Has it been run only @ idle or have you run it mid to high throttle?It could be a flooding issue if the float is stuck or you have varnish built up on the needle and seat.Have you run any Seafoam through it?

I've also run it at mid and high throttle. Again, it seems to run fine at those positions. I did notice that I can't always save it from stalling by pumping the bulb anymore. Sometimes this does seem to flood it as it will stall immediately. And yes, I've run seafoam through it once.

[irishfield]

Brand new plugs. A bit black, but fouled? I don't know. You be the judge.

 

Soaked in raw fuel... carb issue... float bowls overflowing

[DRIFTER_016]

Run some more Seafoam through it.

Use the shock treatment method.

1 can of Seafoam in 1 gallon of gas.

[Sinker]

Yeah, a good dose of seafoam should clear that up....

 

S.

[Doctrt]

Do you really think that would do it? Does it not need to be rebuilt?

[DRIFTER_016]

Best to try before you go out and spend all the $$$ to have the carbs rebuilt.

My guess is you have more than one carb.

My old 90 Merc has 3 carbs.

Gets kind of spendy to have 3 carbs rebuilt and synced.

Especially when a gallon of gas and $14 worth of Seafoam may fix the problem.

[dhickey]

Another option is to take the carb(s) off and soak it in fresh gas for about 24hrs then use carb cleaner to do a final cleaning and let it soak in for about 4hrs then hit it again with the cab cleaner. Wash it out with clean gas and install it .

If that doesn't help than bite the bullet and get it (them)rebuilt.

Edited July 27, 2013 by saltydawg

[Doctrt]

Best to try before you go out and spend all the $$$ to have the carbs rebuilt.My guess is you have more than one carb.My old 90 Merc has 3 carbs.Gets kind of spendy to have 3 carbs rebuilt and synced.Especially when a gallon of gas and $14 worth of Seafoam may fix the problem.

Sounds like a plan. I guess it can't hurt. How much do you figure to have the carb(s) rebuilt?

 

 

Another option is to take the carb(s) off and soak it in fresh gas for about 24hrs then use carb cleaner to do a final cleaning and let it soak in for about 4hrs then hit it again with the cab cleaner. Wash it out with clean gas and install it .

If that doesn't help than bite the bullet and get it (them)rebuilt.

How complicated is it to take off the carb(s)?

[dhickey]

Honestly if you have to ask that then don't do it.

They would have to be cleaned /rebuilt and synchronized.

 

$$$

A good marine mechanic can do it in a day 8-10 hrs.

[Doctrt]

Honestly if you have to ask that then don't do it.

They would have to be cleaned /rebuilt and synchronized.

 

$$$

A good marine mechanic can do it in a day 8-10 hrs.

Good advice. I've done a smaller engine before but this ones a little more important. Thx

[DRIFTER_016]

The difficult part is the syncing.

You need the proper tools to do the job.

[LesCulpJr]

Wow you've been all over the map here haven't you:) I work at a johnson/evinrude dealer part time and deal with these engines on a weekly basis.

 

First of all this is not an oil issue or a plug fouling one.

 

You have a fuel issue

 

Going back to your intial post. If after your engine dies you go back to the motor and the fuel bulb is FLAT or almost there. You have a venting issue. If I miss read that part of your post, my apologies... If your fuel bulb looks normal but you have to pump it up to keep running then you have an air leak in your system. Replace your fuel line

(don't buy an Attwood replacement fuel line)

 

You also gave mention to the fact that you tried a remote tank and experienced the same stalling problem... It could be that you have more than one problem here but they are all fuel related.

 

How long was the motor in storage before you bought it and was it stored properly? If you cannot answer this have the carbs serviced and sync'd. While they're at it have your mechanic test the VRO pump and ensure its working properly. This is a part that will fail over time. The quick and economical choice being to replace the VRO with an older style fuel pump and mix your gas from then on.

 

To keep an eye on your VRO simply observe the oil level in the res. from time to time and make sure its using oil.

 

Thats about all the advice I can give without having one of our mechanics look at it....

 

Keep in mind that gas today is only good for about 60 days after purchase. Always a good idea to stabilize your fuel if the boat sits around for any length of time between outtings... If by chance your motor was stored with untreated fuel you could have a bit of a mess in there.

 

If you are to try an do these repairs yourself please be confident that you can put them back together again:) lol.

I know our marina has started turning people away that come in with handfuls or boxes of parts and who bring in obsolete equipment And we know others are doing the same. We just can't devote the time to it and feel bad charging so much on equipment that simply isn't worth fixing.

That said.... You have a good motor there if you spend the money on it to have it fixed properly

[Fisherman]

LesCulpJr, on 29 Jul 2013 - 11:36, said:

Wow you've been all over the map here haven't you:) I work at a johnson/evinrude dealer part time and deal with these engines on a weekly basis.

 

First of all this is not an oil issue or a plug fouling one.

 

You have a fuel issue

 

Going back to your intial post. If after your engine dies you go back to the motor and the fuel bulb is FLAT or almost there. You have a venting issue. If I miss read that part of your post, my apologies... If your fuel bulb looks normal but you have to pump it up to keep running then you have an air leak in your system. Replace your fuel line

(don't buy an Attwood replacement fuel line)

 

You also gave mention to the fact that you tried a remote tank and experienced the same stalling problem... It could be that you have more than one problem here but they are all fuel related.

 

How long was the motor in storage before you bought it and was it stored properly? If you cannot answer this have the carbs serviced and sync'd. While they're at it have your mechanic test the VRO pump and ensure its working properly. This is a part that will fail over time. The quick and economical choice being to replace the VRO with an older style fuel pump and mix your gas from then on.

 

To keep an eye on your VRO simply observe the oil level in the res. from time to time and make sure its using oil.

 

Thats about all the advice I can give without having one of our mechanics look at it....

 

Keep in mind that gas today is only good for about 60 days after purchase. Always a good idea to stabilize your fuel if the boat sits around for any length of time between outtings... If by chance your motor was stored with untreated fuel you could have a bit of a mess in there.

 

If you are to try an do these repairs yourself please be confident that you can put them back together again:) lol.

I know our marina has started turning people away that come in with handfuls or boxes of parts and who bring in obsolete equipment And we know others are doing the same. We just can't devote the time to it and feel bad charging so much on equipment that simply isn't worth fixing.

That said.... You have a good motor there if you spend the money on it to have it fixed properly

[Fisherman]

never mind, computers fubar.

Edited July 29, 2013 by Fisherman

[aplumma]

We are still at the point that the carbs need to be cleaned and adjusted. A properly working float in the carb will allow gas to be pumped via the bulb and get hard without fuel running down the outside of the carb. It has a overflow vent that is visible from the front of the carbs after you remove the flame suppressor from the front. You can run seafoam or 2/4 but it will not get rid of a piece of debris or a damaged needle and seat on the float. Once an issue is identified fix that issue before you look for a possible issue to cure a problem. Fixing them one by one usually results in less wrong diagnosis and snowballing the path to repair with assumptions.

 

 

Art

[Doctrt]

Quick update. Fuel lines were all replaced as was the bulb (apparently it was the wrong size).. The mechanic felt that the carb was fine. I'm not sure how he came to that conclusion. It could be that he's trying all of the cheaper fixes first which I appreciate, but at the end of the day, I just want it fixed. I did run the seafoam shock method prior to bringing it back in, but with no change. The fuel pump was serviced, whatever that means and he felt there was a problem with the oil pump as well so that was also serviced. I know I'm not giving much detail but I don't have the work order yet. Long story short, it's working a thousand times better. I ran it wide open, no change. Still hauls. At a slow troll it ran without stalling for about 10 minutes on three separate occasions before I opened it up. It seemed to want to stall but it didn't. It shuddered a bit, almost like it was misfiring but didn't let go. When I felt the bulb, it was not close to hard, but when I pumped it, it no longer flooded out and stalled. I was told not to expect the bulb to be completely taut when running, but im still not sure about this. I didn't have a ton of time to run it but it seems that I'm almost there. I think I'm going to clean up the plugs before we head out this weekend in the hopes the misfiring/shuddering is resolved. I'll run it much more over the weekend and give it a real workout. At least I'm more confident that I won't be stuck out in the middle of the lake. Thanks a million for all the great suggestions and help. It's a real tribute to how great this site really is.

T

[BillM]

Time to buy a kicker!

[bare foot wader]

like I said, I have that same outboard, it'll shudder at slow speeds for extended periods, shudder but won't stall on me but I don't troll with it ever, it's not a trolling motor...my understanding (which may be wrong too, some mechanics don't agree with each other) is that at slow trolling speeds carbon and other deposits build up and causes the misfiring and shuddering effect you feel...it "loads up" and you need to run at high speed to blow/burn out the deposits...I was also told it'll decrease the life of your spark plugs....just what my shop tells me

 

glad to hear it's working better for you now, sucks to have down time in the middle of the summer

[Doctrt]

like I said, I have that same outboard, it'll shudder at slow speeds for extended periods, shudder but won't stall on me but I don't troll with it ever, it's not a trolling motor...my understanding (which may be wrong too, some mechanics don't agree with each other) is that at slow trolling speeds carbon and other deposits build up and causes the misfiring and shuddering effect you feel...it "loads up" and you need to run at high speed to blow/burn out the deposits...I was also told it'll decrease the life of your spark plugs....just what my shop tells me

 

glad to hear it's working better for you now, sucks to have down time in the middle of the summer

Thanks Barefoot. Maybe time for a trolling plate to slow things down cause theres no room for a kicker. I don't mind the downtime now, it's the fall that would have killed me!