Stalls in gear

[Kev144]

Hey guys, not much of an outboard repair guy as we work with I/O's mostly.

I have a 88 Blackmax 150 merc. It has the suitcase type cowl. Anywho, it will start up fine and sometimes will idle fine without the fast idle on. As soon as you put it into gear it sputters and then quits. Like its running out of gas or flooding itself almost. It also smokes like a you know what which makes me thing its also getting alot of oil? Does this sound like a fuel issue to you guys? I'm thinking about having a O/B mechanic that i know look at it as i dont have all the time in the word. But im heading back up this week end to check it out first. If you have any tips, please let me know.

Thanks

Kevin

 

[Kev144]

Re: Stalls in gear

FYI...Boat has ran excellent for about a month and a half (recently purchased). WOT at about 5800 RPMs. 70 mph. When going in gear, if i give it throttle quickly, it will go and run fine unless i slow it down to an idle in gear. I have tried adjusting the idle on it but that didn't do anything going into gear. Just seems like its flooding itself or not enough fuel. Not too sure.

 

[Kev144]

Re: Stalls in gear

bump!

 

[CraigC]

Re: Stalls in gear

Hmmm, you said it will "sometimes idle fine" so I'm reading that as it has an idle problem most of the time? Does it make a difference in neutral vs in gear then...or is it strictly when in gear?
Either way I'd suggest you start with the basics - clean the carbs and run a compression test. Sounds like it runs good on top, could be as simple as dirty carbs, or it could be uneven compression - or both!

You're also saying it smokes A LOT, but if it's running good quality oil that shouldn't be the case. That motor is oil injected so this may sound dumb, but did someone premix fuel in it as well? That would give you the kind of smoke you're talking about, and would most likely cause idle problems (among other things) but could possibly be running ok on the top end. Check that out too.

 

[Kev144]

Re: Stalls in gear

When it's cold it wont idle properly with out the fast idle. Once warm it will idle fine with out fast idle. If i give it a bit of throttle it will stay running and will run fine. (not that i want to run it with a problem). It's just when going slowly in gear at a idle (trolling speed) it quits. It just spudders and quits as if tyou had run out of fuel or too much. Having it all checked over by a buddy either today or tomorrow. Will post results

 

[hkeiner]

Re: Stalls in gear

Perhaps your idle speed is set too low. The link and sync procedure for setting low idle speed is done with the motor idling while in gear. If idle speed is set with the motor idling out of gear, then it will idle too slow or die when put in gear. Just a thought....

 

[ncryders]

Re: Stalls in gear

Not to step on your thread... but, I have a 1986 90hp merc having the same problem. Runs great out the hole and top end... but idling in gear, she chokes out. Please let me know what you figure out.
Thanks
Paul

 

[Kev144]

Re: Stalls in gear

FYI it turns out i had a very weak switch box. I had 130 PSI accross all 6 cyl. Switch box was weak causing low spark or something and when putting into gear under load it didnt have enough power to run.