1989 Yamaha 50ELF HELP!!!!

[ppidgursky]

The motor will start while holding the choke button, or using the warm up switch on or about the half position. When you let off the warm up switch, the motor bogs down, and will die out. If you catch it before it dies, and
apply the choke button, it will run fine. For some reason it will not maintain an idle.
The boat sat for a year and before it was "parked", ran like a champ (so I am told). I have drained all the old gas out, put new plugs, new batteries, and have cleaned all three carbs. I am stumped.
Any Help Would Be Great

 

[Ray Neudecker]

Re: 1989 Yamaha 50ELF HELP!!!!

You still have all of the symptoms of a fuel restriction. A bad fuel pump can cause these problems.
Many times cleaning the carbs has different meanings for different people. In my book,if you havent disassembled and soaked the carbs, replaced the bowl gaskets and reset the floats, you haven't properly cleaned the carbs.

 

[ppidgursky]

Re: 1989 Yamaha 50ELF HELP!!!!

Thank You for the response.

I will try to find a new fuel pump, but i have another question to go with this one.
Someone told me to try and choke out the carbs with my hand. When I tried that to each carb, the RPMs increased making it run pretty smooth. What does that mean?

 

[Silvertip]

Re: 1989 Yamaha 50ELF HELP!!!!

Using your hand on the carb is the same as applying the choke -- it richens the mixture. You have a fuel restriction problem. Try squeezing the primer bulb when the engine bogs. If it picks up the fuel pump is the problem or there is a restriction between it and the pickup in the tank. Make sure the tank vent is open. If all of this checks out, go back to the carbs and make sure every passage is squeaky clean.

 

[ppidgursky]

Re: 1989 Yamaha 50ELF HELP!!!!

Appreciate it.
I have a new fuel pump, carb rebuild kit on order, should be here hopefully this weekend.
I tried squeezing the primer when its running and it did no good. The primer bulb was stiff and when I squeezed it it did not help.
I am going crazy here. What would be the best product to soak carbs in, or would canned gum out work?

 

[mikesea]

Re: 1989 Yamaha 50ELF HELP!!!!

Be sure to TOTALLY disassemble the carbs and soak them in a carb cleaner.Be sure all plastic and rubber parts are removed before soaking.After cleaning all the cleaner off,with soapy water ,have a can of aresol parts cleaner and blow through all passages.These Yamahas are notorious for carb probs.after being set up for a while

 

[ppidgursky]

Re: 1989 Yamaha 50ELF HELP!!!!

Thank you. I will tare into them this weekend. I will let you know what happenes. I appreciate all the advise..

Keeping my fingers crossed.

 

[ppidgursky]

Re: 1989 Yamaha 50ELF HELP!!!!

Alright, here we go.
I cleaned and rebuilt the carbs and replaced the fuel pump. It seem to have fixed the low idle stall, but uncovered a couple other things. 1st, when I try to accelerate, the motor will bog down. I have to pull back and wait a few seconds before it will kick in. When it does it works well. Sounds to be a air mixture issue to me. Correct?
2nd, the motor runs at an idle then will sound like it cuts out for a spit second then catch back up. If you can hear it, listen to this (http://www.geocities.com/ppidgursky/engine.wav).
Its not the greatest of quality but you'll get the jist of it. (The reving of the engine is me trying to duplicate the sound.)
When it makes the cutting out sound, the motor actually kicks a little. It does it somestimes alot, and sometimes every so often.
I took the boat to the lake and she ran good otherwise.
Again, any help would be greatly appricated.

 

[rodbolt]

Re: 1989 Yamaha 50ELF HELP!!!!

its still running lean, do the carbs yet again.
that kick is called a lean sneeze and is the lean mix burning off in the crankcase but its contained by the reeds.
the passages are very small and clog very easily, did you swab out all the fuel lines with a sstring and a patch using carb cleaner? if not its possible that same nasty gunk that was in the fuel bowls is flaking off the inside of the fuel lines and creating isssues.
double check all the float heights and pilot air screw adjustments as well.

 

[ppidgursky]

Re: 1989 Yamaha 50ELF HELP!!!!

OK, The float hights. Do you measure from the edge of the carb to the top of the float, or to the middle of the float. I have reading online and I have read both ways.
And I will try cleaning again.

I appreciate the help.
Thank You

 

[rodbolt]

Re: 1989 Yamaha 50ELF HELP!!!!

did you actually remove the pilot air and pilot fuel jets as well as the main jet and emulsion tube to carefully clean them and the passaages?
did you use new rubber discs on the plates? did you use new2 or good used rubber plugs in the pilot fuel hole?
by memory I cant see your carbs, but I have done more than one set .

 

[ppidgursky]

Re: 1989 Yamaha 50ELF HELP!!!!

When I did the rebuild, i replaced the all gaskets, air mixture pilot screws, jets, float and assembly, rubber stopper under the float, and the o ring on jet. The only thing I did not do is the large brass "jet"(for lack of the correct term) and I did not use a string to wipe out the fuel lines. I did spray these two parts with gum out, but I did not wipe them out.

 

[rodbolt]

Re: 1989 Yamaha 50ELF HELP!!!!

did you remove the pilot fuel jet and main jet and emulsion tube ?

 

[karlster]

Re: 1989 Yamaha 50ELF HELP!!!!

Just to echo what Rodbolt is saying. I had my carbs torn apart repeatedly looking for a bad idle cause. The problem was a filthy emulsion tube. It might seem stuck at first but a gentle tug on it should free it up.

Karl

 

[ppidgursky]

Re: 1989 Yamaha 50ELF HELP!!!!

OK, I have been able to follow you guys up to now. What/where exactly is the emulsion tube, and the pilot fuel jet.
I replaced the needle and the tube it sits in. But the emulsion tube...I am not following.

 

[karlster]

Re: 1989 Yamaha 50ELF HELP!!!!

On my carb, the emulsion tube is behind the main jet. I unscrew the main jet and behind it is a brass tube roughly 1/4" diameter with small holes drilled crosswise through it.

Once you get it out it is easy to clean with a fine piece of wire, compressed air and an appropriate solvent.

Good luck
Karl

 

[ppidgursky]

Re: 1989 Yamaha 50ELF HELP!!!!

Well, I tore into them again. I found the emulsion tube. And like you fellas said it was pretty nasty. Mine is under the float next to a black rubber plug. I scraped some crap off and you can actually see the brass again. I am going tomorow to get carb cleaner to soak them. Any suggestions on a brand or type?
I hope this does it. I am new to the hole boating thing and I'll tell you, This will discourage a fella. Hopefully there will be some good weather this weekend so I can hit the lake. I let you all know how the cleaning goes.
Thanks again for all the help. You guys have been more incitful than the seloc manual.
Peter

 

[rodbolt]

Re: 1989 Yamaha 50ELF HELP!!!!

just beside the main jet you should see a rubber plug covering a hole, remove that plug. down that hole is the pilot fuel jet. remove that jet and carefully clean it and the passages.
that is the pilot(idle) fuel jet.
if a rubber plug is missing it wont idle or run correctly.
its a shop funny to walk by and lay a used plug on the worktable after a tech has assembled the carbs to the engine .

 

[ppidgursky]

Re: 1989 Yamaha 50ELF HELP!!!!

I was wondering what the was under the plug. I tried to remove it but it was stuck pretty good. Is that adjustable like the air mix screw or is it stationary.
I am going to wlamrt later this evening for the carb cleaner. Hopefully we can get this wraped up.
Thanks again.
Peter

 

[ppidgursky]

Re: 1989 Yamaha 50ELF HELP!!!!

OK, I am back. And still frustrated. I tore them apart again. I scrubbed and soaked everything I could. Got them back together, put them on the boat and truned the key......
Ran good and strong for about 30 sec. and then the Idle dropped and she cut off. I adjusted the air pilot on all three and found a happy medium. There is no hesitation when I hit the accelerator, but when I back off the idle it slows and dies.
I checked the seloc manual and they say the rpm at idle should be between 750-850. I got her to smooth out by adjusting the idle. She will run good at 1000 rpm. I also read about the float hight.
It reads "Hold the mixing chamber in the inverted position, (as it has been held during the past few steps). Measure the distance between the top of the float and the gasket surface of the mixing chamber. This distance should be as specified in the Carburetor Set-Up Specifications charts".
I found the spec for the "Float Drop Setting" it is .55"-.63" (14-16 mm).
Since I replaced the floats during the rebuild I am wonder if the measurement got scewed. How do you adjust the hight, if possible?