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Hi,
I bought a 13 ft whaler with a 1990 Evinrude 50 2 weeks ago tomorrow.

When I went to test drive the boat it would not plane. The PO said it did have a low idling problem but other than that it should have ran fine. He had a marina come by and work on it. They kept it for a couple of days and rebuilt the lower carb as it was gummed up they said. This still did not fix it and then they said they found the issue-it was a condensor grounding out.

I took the boat home and ran it the next day. It still did not want to idle in neutral but otherwise it ran fine.

Last Sat I took it out again and this time the boat idled fine but would not plane, until I held in the choke/fuel injector. At that point it planed fine and ran fine as long as I held in the choke . After about a min or so it ran fine without the choke though the idle issue returned. It ran like that for about 4 hours till I went home.

I am off tomorrow and want to work on it while i have free time.
A friend says I should replace the fuel pump and the fuel lines/inline fuel filter. Do fuel pumps act like this when they are going bad ? Thanks.


(changed abbreviated year to full 4 digit year for clarification)

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Betting it is the other carb. I had similar issues with a 90 hp 2 stroke Yamaha. Problem was migrating from one cyl. to another,[ 3 cyl. 3 carbs]. You can check by pulling plug wires one at a time. I completely explained this to the Yamaha dealer before and also when I dropped the boat off. Three weeks later they called to say they had replaced the plug caps, which I had requested, but had never alleged was the real problem.

I asked if they had water tested the boat and was told that it was happening that morning. I requested they call if any issues as it was 150 miles one way to get the boat.

No call so I left in time to get there before 5PM closing time. Arrived to be told "the lower carb needs to be rebuilt". It took me 15 minutes of haggling to get to speak to the mechanic. As soon as I did, I asked if it made any sense to only do 1 carb. "Well once they are off it only takes about 15 minutes each to do the rebuild"
Rebuild kits are about $15 each.

When I asked the service tech why he was only planning to do one, the answer was "well I thought you were in a hurry to get the boat back".

Probably a good idea to get rid of fuel and use fresh.

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Makes sense to rebuild the carbs. The primer (what you called the choke/fuel injector) basically squirts fuel in downstream of the carbs, so it's good news that it ran OK when you used it - that means your fuel pump is likely OK as it is able to pump enough to keep you going.

You do not want to run the motor in it's current condition - running lean is bad. Get the carbs rebuilt, or do them yourself, and you'll likely be good to go!

Tim

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Hello supersport75, going through the carbs will be your best recourse (as mtown mentioned). Sounds as if your fuel pump is working but, if it has been on the motor for some time it might be good insurance to replace with new.

I suggest searching you tube or other web media for information regarding your carbs disassembly/assembly tips. Consider a shop manual if you haven't already for your 50hp. Having a notion as to the adjustment position of the air/fuel mixture screws will be the key and obviously proper fuel float adjustment as well. Keep note of the throttle linkages' current setting.

I too went through a similar carb rebuild with my Yamaha 90 sometime ago. I thought there was a problem with fuel circuit, turned out to be a bad temperature sensor mounted on the cylinder head. The sensor sent the motor into a "Safe Mode" condition with controlled rpm which in turn made me think it was the carbs. Even my local boat repair shop missed the sensor issue.

Hope you get it straightened out...
Best,
Angel M.

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Thanks guys. I decided to do the stuff I know how to do myself so today I changed out some of the fuel lines and filter. I said some because my engine has a plastic fuel rail and one of the nipples broke off when changing the line.

I ordered a new one but in the mean time I have some friends trying to build me a new one so I can enjoy the long weekend.

I did talk to the shop where I got the parts today,,,and like you guys, they though it was the carbs or trash in the system because it is an intermittent issue. Well I know trash was part of the problem because when the first shop took the carb apart there was black gunk in there that we think were fuel lines breaking down.

anyway if the carb needs rebuilding I think I am going to let a shop do that for me....Thanks...

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If possible ask if you can see the carbs taken apart. You will not believe the tiny port that allows the fuel from the bowl to pass into the throat. This is why it takes almost nothing to clog.
I am still to chicken to attempt a "rebuild" on my larger outboards carbs. I have done this on a 4 hp outboard and a 10 HP generator. Both times it was the tiniest jet clogged, a sewing needle and 2+2 spray took care of the problem.
I am currently trolling craigslist for a junk motor so I can perform this and other tasks without risk of Oh S%#@ moments.
Good luck and please keep us informed of your results. It is a big reason this site is so popular.

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Thanks I know Hondas have tiny tiny jets and I learned to never leave gas in it :)

Well some of my facebook friends did come through and between them and what I did I made a temporary fuel rail. As I was putting it back together I found another fuel line that feeds the choke was getting soft where it connected so I was about to replace it when i just *touched* it and another even smaller nipple fell off! Not sure when OMC started using Mexican plastic parts but I am paying for it now. Part is cheap but of course had to order it so there goes the boat for the weekend again. But one of my friends said it is better to find out now while it's sitting in my yard rather than later out in the middle of the bay and I guess he has a point just a bit bummed out that I have really only had a chance to use this boat 1 time since I bought it 2 weeks ago.

I bought a new switch panel to replace the 40 year old one and it fits but darn it, the positive side touches the steering mechanism inside the console so I am going to have to go from a 6 switch to a 4 switch and build some kinda of frame so there is no hole in the side of the console. Oh wait getting off topic here , wrong section for wood questions! Have a great weekend....

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I have had problems with 3 different Yamahas for kickers with idling and top end problems. All were 4 strokes and all had problems with junk in the carbs. I took the carbs apart numerous times, scrubbed them with mixed success. They ran better but but not great. The F15 and F9.9 were too heavy for the boat, the F6 was just right.

I remembered that I had an small ultrasonic cleaner from Harbor Freight. I used that with some dilute Simple Green. When I started the US, there were plumes of gunk that came from every single hole in the carb, despite all of the scrubbing I had already done, some holes were too small to clean. After a minute in the US machine, i rinsed and then dried the carb with compressed air. After reinstalling, they all ran like a champ. Just make sure you get them rinsed and dried quickly. You don't want corrosion in the carbs.

I've made a real effort to run ethanol free gas, use Stabil, and run the engines out of fuel when they will sit for a long period of time.

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Sorry to hi jack, but you wouldn't happen to still have the F9.9. I have been looking for a choke assembly for mine for 6 months.

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I am trying to find a good shop to clean the carbs if it comes to that , I just don't want to try that myself at this point. I may do the fuel pump myself if I can find a how to video.

Here is a dumb question: I know you must drain the carbs on a 4 stroke as my manual for my little honda kicker says so. But I have 2 friends that have been helping me with this boat and they are giving me completely conflicting advice as far as this evinrude (2 stroke)goes. One says I should NOT run it dry as it will make the engine run lean and the other says I should run it dry (for the winter). I know a 4 stroke would run lean too so I am thinking friend # 2 is correct.

Once I get these fuel issues resolved I don't want to go through this again.

On a good note, I got the bow lights working last night, just got to figure out how I want to switch them. Stern light will take longer..I found out they used part of an old arcade game as a mount for the stern light if you can believe it!

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Do not run any multiple carb motor dry - results in one or more cylinders running lean, or in the case of 2-strokes, running without lubrication. Instead use a fuel stabilizer on your last trip of the season, then once you get home, fire it up on the muffs, fog the motor down and drain the carbs via the drain screw.

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I wouldn't run the carb dry on the 2 smoker... I'd definitely look for ethanol free gas and treat it with Stabil and fog the engine.

The multi carbs are very complex mechanically and waaay beyond me. You be best served by finding a real mechanic to work on it. I'm sticking to single carbs on the little motors and lawn mowers. I think carburetor translates into "the Devils Work" in German...

Just winterized my F6 today. Sad to end the summer. Still have to do the F90 and F225 in a couple months.

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Thank you that makes sense

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The problem is I don't know any anymore. The one that I knew was good has retired.

A friend just messed up my fuel pump trying to put in the kit and he is going to try get him out of retirement at least long enough to fix the boat, so maybe things will get a bit better soon..I hope :)

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I had a similar problem with my 1992 evinrude 50hp though it idle ok it would throttle up when not under a load but would not throttle under load except when playing with the choke.
I did a carb rebuild but it didn't fix the issue, finally I found that rollers in the throttle/timing linkage had vinyl sleeves that were missing. This apparently through carbs out of sync with the timing. Replaced the sleeves with clear thin vinyl tubing and WOT throttle was now possible.

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Thanks I will keep this in mind if when it's back together and it is still not working right.

I may have a mechanic if it comes to that. My friend was able to contact our old mechanic and he passed on a name of someone he trained. He also said not to waste time trying to rebuild the fuel pump just get a new one so I should have that coming in from amazon tomorrow. But he also said these are long stroke motors and are problematic and always gave them fits. I hope he is wrong about that.

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Just a FYI:

Evinrude has redesigned the fuel manifold. It is no longer made of cheap plastic but brass. Heat should not be a problem anymore. I am going to try and post a link with a picture of what it looks like now:

https://scontent-dfw1-1.xx.fbcdn.net/...7977_o.jpg

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The new parts made a difference! Got to test boat yesterday and it now planes fine and now actually idles though it still has a low rpm miss. After my friend had so much trouble with the fuel pump, I was worried I wouldn't be able to rebuild the primer pump , but it came out just fine.

I am going to try and rebuild the old fuel pump myself just for the learning experience.

Thanks for all the help.