1986 85 HP Force carb adjustment

[ronaldecole]

Can anyone tell me where the low and high speed carb adjustments are on a 1986 85 HP Force model 856X6M when you are in the boat looking at the throats of the 3 carbs. The Seloc manual I have -- (024-1) 1100 on page 4-20 fig. 31 shows a main fuel jet to the left of the carb and the idle mixture screw at the top of the carb but I am not sure of the relative position of that illustration. If I am standing behind the motor I see an adjustment screw on my left, so it doesn't quite match up to the Seloc.

The reason I am asking is because I am having a problem with the engine stalling on acceleration then hard to start. I believe it is fuel related since the electrical seems fine -- I've toubleshot the elctrical system using the Force troubleshooting guide and have a nice "blue" spark on each plug, along with new Champion plugs which are black when the engine is running.

The carbs were rebuilt by a marina last year for the same exact problem. I have been on the water 3 times this year without any problems then "bam" I was out last weekend and it started stalling and hard starting. I've been through the fuel system: the ball stays hard, I've already put a new diaphram in, rechecked all my hoses for snugness and leaks, checked linkage for binding and have been using fresh gas at the correct mixture and compression is good.

When I brought the boat back home that day it started right up with the muffs. But this is typical of what it did last year before the carbs were rebuilt - it would stall, not want to start in the water, but when I brought it back home it started fine.

Thanks, Ron Cole

 

[pnwboat]

Re: 1986 85 HP Force carb adjustment

There is no low or high speed adjustments that I'm aware of. Just idle mixture. Have you done a "link and sync"? The butterfly valve in all three carbs need to be moving in perfect unison, other wise you may experience poor idle and starting.

Plugs really shouldn't be black. I guess that's kind of subjective though. They should be fairly clean. Sounds like it may be running rich? Do you have pictures?

I'm not sure I would totally discount a weak spark. Try pulling one plug wire off at a time and see if the idle changes. If you pull one off and it has no affect on the idle, then I would suspect a problem with spark on that cylinder.

 

[john from md]

Re: 1986 85 HP Force carb adjustment

Check your plugs. These engines tend to foul plugs easily especially when you use the cheaper 2 stroke oil. Clean them or throw a new set in if they haven't been changed in a while and see what happens.

John

 

[ronaldecole]

Re: 1986 85 HP Force carb adjustment

Thanks for the feedback -- since I fried my starter trying to get it started again and again, I will get back when my starter comes in next week.