Engine stalls

[sfmaster]

I got a 85hp yamaha. It stalls at sart up and while running it stalled on me and turned off. It starts up after a few minutes, but I need to choke it a few times while shifting to foward it runs a few then stalls until it turns off. Any idea whats causing this? I changed the spark plugs and it wont stay in idle it turns off. Nay help will be appreciated.

 

[99yam40]

Re: Engine stalls

without any info on the motor I would say that you need to pull and clean carbs.
Is that enough Nay help?

 

[sfmaster]

Re: Engine stalls

Thanks for the reply and I apologize for the mininum information. My engine is an 1993 yamaha 85 horse power two stroke. My first encounter with the problem was on my way back to the dock. The engine slow 3200rpm when usually I'll bring it up to 4300. It wouldn't speed up. I slowed it down then speed up again. I did it for a few times and the speed picked up to 4300 and ran fine. When on wake it would turn off and I had to kleeep hitting the choke to keep it running. The day took my kids out and I had to keep hitting the choke in order to get it in gear (forward). When I reached the resume speed sign I picked the spped and it didn't even make it to 3000 rpm, it stalled and turned off. The engine turns on but if not throttled it'll turn off. And when I get it to run , using the choke, it doesn't pick up speed and shuts down. I changed the sparks and water seperator. I even change out the fuel line and pump out. I cleaned out the feul filter, it was dirty and seemed to have sand like particles. and looked a bit like slime or white milky substance. Could it need a carb job? Thanks!:redface:

 

[99yam40]

Re: Engine stalls

Still no model #

definitely needs carb job and the tank should be cleaned if you found that kind of stuff in the system also add a 10 micron external water/fuel separator/filter

 

[sfmaster]

Re: Engine stalls

The model number is C85TLRR. I add a 10 micron external water/fuel separator/filter. Today I took off the fuel pump, weird as it sound, i saw particles inside and flushed it out with carb cleaner I put it back together and started it up. Took time, i guess due to the carb cleaner. it turned on and idled fine . I throttled it to 21 rpm and didn't turn off. I turned it on and off a few times and seem to work fine. I tried again after a few minutes and it started to act up again . wouldn't hold in idle. I primed it, and air and gas ws coming out of the fuel pump, not much, but noticable. Could I have a bad fuel pump? Or this a way to check that the fuel pump is working as it suppose to?

 

[99yam40]

Re: Engine stalls

There should not be anything coming out of the pump except to the carbs. Also never put carb cleaner on rubber or plastic parts unless it says it is safe to do that on the label. Sounds like you tore something and pump is bad

 

[sfmaster]

Re: Engine stalls

My next move should be replacing the fuel pump, right? :redface:

 

[99yam40]

Re: Engine stalls

My next move should be replacing the fuel pump, right? :redface:

Unless you pull and find something that can be fixed without replacing the whole thing, it may be easier to just replace but who knows

 

[sfmaster]

Re: Engine stalls

Okay. I'm going to get the feul pump and install it today. I'll post the results. thanks!:redface:

 

[wellsc1]

Re: Engine stalls

In any event, keep fixing it until it's right. DO NOT take it out anymore, or chance really breaking it.

Particles may already be in the carbs. I would clean the carbs and the fuel tank in addition to fixing/replacing the fuel pump.

 

[sfmaster]

Re: Engine stalls

The fuel pump I ordered won't make it in until Monday. So I took another gas sample and found it has water and junk in the bottom of the glass sample I took. Tank is filty. I definately need to clean out take. Also while pumping the primer to get gas out, the hand pump stayed compressed a few times as if line was clogged. Would it be a good idea to get fresh gas in few gallon can and try running the engine to see if it runs okay? Since I have the weekend free and the fuel part won't arrive until next week. What you think?

 

[sfmaster]

Re: Engine stalls

Today my buddy and I cleaned out the tank replaced the water filter seperator with a new filter and check the gas again. The gas was perfect, clean. We did find that the fuel connetor (female) was not working properly and was replaced with a new one. Engine starts now using choke then idles fine. But , when I put in forward and reach 25 rpm it seems to lose fuel pressure and turns off. When I try to turn it on again it hesitates to start. I need to play with the choke in order to get it to idle. I haven't changed out the fuel, its still the old one. Could it be the fuel pump causing the engine to turn off when it reaches 25 rpm?

 

[sfmaster]

Re: Engine stalls

:redface: my last try here! I installed a new fuel pump today, results are the same. Idles with help of the choke. When I get it to run it won't even go over 25 rpm. It loses power , shuts down. Takes time to restart , then happens again at 25 rpm! Any last suggestions or help here, pleaase!

 

[krisnowicki]

Re: Engine stalls

carb job time...

 

[sfmaster]

Re: Engine stalls

Thank you! krisnowicki

That's what I'm going to do. I will post the results. It might be a few days. I called a mechanic and he's charge me $125.00 for the Carb job. I think thats a reasonable price. He will also de compression check, fuel line check etc.

Once done I'll post the findings from the pro. The boat is on it's way to the shop today.

 

[sfmaster]

Re: Engine stalls

Oh yeah finally! Problem solved. It was the carbs. They were filty, super filty. I had them cleaned out and compression check. My 1993 85hp yamaha compression check resulted in 117 each. Wow! the mechanic couldn't beleive it! Anyways, lesson learned >> clean gas tank , replace or install water seperator(a must have), gas filter replace. Their was so much build up in the carb, it was unbeleivable that it even started up. Well, thanks to all for the help. I will hopefully go fishing this weekend with the kids>>

Happy boating to all!

 

[cousinabe]

Re: Engine stalls

good news!

does that motor sit for long periods of time?
you may want to run your final outing with stabilized fuel so it gets in the carb before you store it.
i use star tron with great success. it would keep the lingering fuel in the carbs from gumming up during lay up.

 

[sfmaster]

Re: Engine stalls

cousinabe,

well, I live at Florida so my boat doesn't really sit more than two months without running it. But can I still use star tron everytime I gas up or is it receommended as a monthly type treatment.

Thanks!