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Mariner 60hp bigfoot weird issues

T

trynhooker

Regular Contributor
Don't have the model# with me at the moment but here is the issue.
I rebuilt the carbs a few days ago, set idle/timing. The engine ran fine at customers house on the hose. I set the idle a little high so when he got it to the water he wouldn't have to adjust the rpm.

He launched boat Friday, idled fine he said, he left ramp, increased throttle up/down a few times, turned engine off/on, still idled fine and ran fine.

He said he went about 400 yds then the engine died and he could not get it running again without having some throttle applied (kinda like when your idle jets are clogged).

I went down today and the engine would barely run even when throttle was applied, and no chance of it idling own it's own. I adjusting timing and carb mixture screws but very little change if any. All 3 cyl's fire and have 92-95 compression.

I noticed the bottom carb had a fuel leak drip from the drain screw (main jet access screw), which it didn't have when I did the cleaning. Tightened up the screw and it would never tighten, and actually got to the point where the seal became squished out. Thinking maybe the bowl is cracked so taking a new one when I go down next time.
When watching the fuel leak from the drain screw, it also appeared to be milky colored.

I'm curious if this leak is causing the engine to be completely inoperable?
Also, I noticed when I got the engine to idle some with a little bit of throttle, and tilted the engine up past level, the rpm would increase. I believe that affect was from forcing the fuel in that bowl to be in the front of the bowl and possibly allowing air to be sucked in from where the drain screw leaks?

This is just a weird situation from my experience. Would appreciate some assistance soon if some of the more seasoned experts take a read here.
Thanks all
 
Forgot to mention in original thread. When doing the carbs I noticed the inlet needle's do not have the tiny wire clip to clip it on the float bowl. The end of the needle's are just flat. They also did not have magnetic tips like I have seen on a older Mercury either..
The needle I assume is just floating until the float height levels out and closes the inlet.
 
Here's your problem. (See photo.) The fuel tank got moisture in it and--thanks to stupid ethanol--the dreaded white gook (bottom of the jar) has formed. The only thing to do now is pump it out for no known additve will make that white crap burn.

Jeff
 

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Jeff, yea I kinda thought that also but when I did the work I was running the engine on the same fuel tank, 3 days later I had the problem described. Either way, I had to order a new fuel bowl for that bottom carb since it has the leak and the screw seems to not bottom out.
 
Recheck the float adjustment. Many of the Walbro carbs do not have the little clip on the needle, they just kinda stay in there and pressure (from the hinge, or gravity) does the rest.

It sounds to me, aside from the main jet leak, that the floats are a little out of whack causing an "extreme rich" condition (which would explain it "kinda" running with a bit of throttle.
 
Update on the idle issue.

I replaced the bowl on the bottom carb. Couldn't get the main jet out so I ended up making one..(used the old drain screw, ground it down, cut new threads and drilled the same size hole in it), worked like a champ.

Got the engine to idle fine and ran in gear at the pier, ran good.

Customer replaced fuel tank, fuel filter, primer bulb this past weekend. He took her out and said it idled fine but would not run WOT. Said it sounded like it wasn't running at full power. When he got back to pier, shut her off, then it wouldn't start or idle again without throttle applied?

One thing I noticed when I replaced the fuel bow...I was idling the engine without the breather cover on. I noticed a little smoke blowing out from the middle carb. When I would give it some throttle the smoke got stronger.

Appears that maybe the middle reed might not be seating fully, although there is no backfiring (common with reed failure).
Going to rebuild fuel pump when parts come in since he doesn't know when it was ever done (he just got the boat), and maybe resolve the WOT issue.

Any thoughts on the smoke issue, please advise..
Thank you

On a side note...The flat rate book says 6 hours for a reed job? That sounds like a misprint cos I can't see where it would take 6 hours of labor. Can anyone second check this in their flat rate manual? It's a Mariner 60hp 3cyl bigfoot.
 
Rebuilt the fuel pump today, it was the main cause of the rough idle..It wouldn't have last too much longer so it was good we changed it..

Engine idles fine now in neutral and in gear.

Still have the issue of smoke emitting from #2 carb. Ran around the lake about 30 min and engine will not run at WOT.. It does run decent at 1/2 - 3/4 throttle, but at full throttle it seems to bog down a bit.. I believe it is due to the #2 reed which is allowing the fuel mixture to blow back out of the carb, making the engine run on 3 cylinders but leaning out #2. Performed a complete sync/link again today also just to be certain that isn't an issue.
Customer is ordering reed parts to replace #2 reed assembly.

Please chime in if you have any suggestions about the #2 carb issue.
 
As I expected. Finished the job today replacing the middle reed..See pic...

Only bad thing is I didn't see the broken piece anywhere... Then again, someone else could have worked on the engine before I did and before my customer purchased the boat...IDK..IMG_0453.JPG
 
Hi Guys, I'm new to this boating thing just recently bought a secondhand 60 Bigfoot Mariner On a Gemini 400 commander semi ridged. The motor seems to be in great nick, it's a 1999 model.... No missing parts... I took her out a few weeks ago for my maiden voyage and she ran ok except for a few splatters which I assumed was due to her standing for sometime. Two days ago a did my own service just cleaning the carbs and replacing the spark plugs. I've bought and new fuel tank with fresh fuel. Now here's my issue with the ears on she runs perfect in neutral and in gear not go over 3000rpm for safety. Put her in the water today and in neutral she idles perfect up to 5000rpm but when I engage her she splatters and only goes up to a very flat 2200rpm. Put her back into neutral and she's up to 5000rpm. This spoilt our day.....

any advice out there............????

TBone71
 
My motor is a 1999 60 Mariner Bigfoot. Serial number 0P029811. When she is idling the revs can go past 5000rpm however I don't do it frequently as I know it's not good for the motor however when she is in the water then she won't go past 2200rpm. I have recently service the carbs and bought a new fuel tank with fresh fuel.
 
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