85 hp chrysler will not stay running

[mccubscout]

Hi all. New boat owner here. Need some help. I have an 85hp chrysler, 3 cyl, model # 856gh2k, ser# 1082. Motor would not run when purchased. Replaced ign switch, Battery and stater solinoid. Yahoo!! she ran great. We put her in water. Engine ran great..... steering did not. Repaired steering but when we went to start her she only started then cut off. Battery is good. Fire on all plugs. Gas to all carbs. When opened wide all cylinders seem to work. when in neutreal she cuts off. When i take plug wires off top and middle plugs there is no change in motor. When i take off bottom plug wire she quits. I switched plugs and wires only to get same result. help!

 

[roscoe]

Re: 85 hp chrysler will not stay running

Well since you already checked for spark and fuel, the next step is to check compression. A little $25 gauge will do. All 3 plugs removed, wires grounded, throttle at full. <br /><br />Maybe you can borrow a gauge if you don't have one.

 

[mccubscout]

Re: 85 hp chrysler will not stay running

we check compression when it would not start. THen it checked ok.

 

[eurolarva]

Re: 85 hp chrysler will not stay running

Does this motor have one or two carbs? If two carbs is the two cylinders that have no effect when you take the plug wires off providing gas for those cylinders? You mentioned when you removed one and two plugs there was no difference in motor performance however when you removed number three it quit. If you are sure those two cylinders are getting spark and compression is good I would take that carb apart and see what is wrong. Could be a stuck needle valve not allowing gas for those cylinders.

 

[CoachHolland]

Re: 85 hp chrysler will not stay running

The 85HP Force has three carbs. <br /><br />what eurolava suggested is right though. Check that and also you might also want to switch your cd module around and see if that is causing your problem. If there is a problem, you'll likely see a change in performance by pulling one of the other plugs.<br /><br />Are you just getting spark or are you getting *good* spark to all cylinders? Weak spark can be just as bad as no spark.