Chrysler 75hp dies at high RPM then cures itself...

[Chris P]

70's Chrysler 75HP model #T750H91A. 3 cylinder, electronic ignition. Bear with me as I'm throwing everything I think pertinent out here:<br /><br />The last 2 seasons, I pull the boat out of the weeds in the spring, connect the hose, start 'er up and she purrs just fine. Put it in the lake and idle perfectly away from the access, no prob's. Open her up after about 5 minutes (no wake near access) and I get power for a minute, then dies like a no fuel situation. After a couple restarts and stalls under power, we're back in biz. Replaced all fuel lines, bulb, fuel pump last year and still had prob once more, then fine. This year, same problem first time out and took way more time to smooth out. Second time out, I'm being towed back to the landing as it never ran right. Suspect overheating, t-stat is fine, replacing water pump just in case, but never get a buzzer. Anything else to check???

 

[Terry H]

Re: Chrysler 75hp dies at high RPM then cures itself...

chris...The first thing I do to troubleshoot a 2 stroke outboard is pull the plugs and make sure there is fuel getting to all cylinders. Then, on the stbd side of your motor where fuel line attaches there is a plastic cover with a filter screen inside that needs checking and cleaning periodically...if that's ok pump the bulb when you are idling, if that kills it you need to pull the carbs and replace float valves and maybe floats...if not, pump the bulb when it starts to die, if that helps, check the fuel tank for venting, or possible fuel pump. I am assuming that the compression and spark are ok, and you have a fuel delivery problem...either too much or too little...just a Thought

 

[Chris P]

Re: Chrysler 75hp dies at high RPM then cures itself...

Hey thanks...had checked all carbs for fuel supply & the filter is clean. But have never tried squeezing the bulb @ idle. I do get lots of fuel in and around the airbox/intake/whatever one should call it. Any other quick carb tests I should perform?

 

[Terry H]

Re: Chrysler 75hp dies at high RPM then cures itself...

You can pump the bulb when not runnin and see if any gas comes out in carb throat...that would mean needle and seat not working properly...Choke it when warm and idling...should shut down...just a Thought

 

[Chris P]

Re: Chrysler 75hp dies at high RPM then cures itself...

OK - finally got the cooling system reassembled. Anyone besides me love trying to wrestle that lower unit back onto a 75 horse? Next time the whole thing's going upside down...it's a Chrylser, so I can't make it any worse, can I??? Anyway, when idling, squeezing the bulb has no effect on motor. Choking does kill it. BUT, when pumping the bulb, it never gets to the point that I can't keep squeezing more fuel through. No matter what, I can always pump more fuel into the motor, running or not. Does that indicate float probs? This thing does sit over the winter with old fuel/oil in the carbs and I just learned what de-carb meant earlier this week. As stated above, this has usually been an early season-only problem.

 

[chads15]

Re: Chrysler 75hp dies at high RPM then cures itself...

The Chrylser's are great motors. Force are good.. they are all good if you take care of them. But im leaning on a sticky needle seat or float problem in your case. I would say rebuild the carbs. Its quick, easy and cheep. Its due anyway.

 

[KCSmith0708]

Re: Chrysler 75hp dies at high RPM then cures itself...

I have a '88 Force 125HP on a 19' Bayliner Capri. Here's a few simple and inexpensive things to do.<br /><br />Recently it started to hesitating and cutting out at WOT. I cleaned the carb's with Sea Foam Deep Creep spray then replaced the fuel pump Diaphragm and gasket ($4.70) which took about five minutes. The original Diaphragm had stretched out and was not delivering the fuel at higher RPM's. Runs great and it was simple. Try this before touching any carb or timing adjustments, and do invest in a manual.<br />Best Regards, Kevin