1990 90 hp Force idle/gas problem?, please help

[evil^^]

Hi, I just recently boat a 1972 Chysler 15" Tri-hull with a 1990 90 hp Force motor. I'm new at boating and just boats in general. I paid very little for the whole setup, so I don't mind putting some work into it. Last night when I was at home I replaced the spark plugs and put the muff on at started it right up, idles okay, put it into gear and it went. When I get to the lake, I start it and it has a rough time idling, and will just die somtimes. If I start it quick and put it into gear and give it gas it will go. I had it pushing the tri-hull about 30 mph last night. I noticed after going around the lake if started to lose a little power. When I got to shore I tried to start it agian and it seemed like my battery was dead. If had enough power for the trim, radio, and lights. You couldn't even hear a clicking sound from the motor. about 30 min. later it started no problem. Basically I was told to take the carburator off and clean the float bowls, b/c they may be gummed up. I have read the forum and hear positive and negitive things about the force motors. I'm not sure how long the boat has sat, but I put new plugs and new gas in it for starters.

Thanks for all you help.

Tony

 

[bowhuntrrl]

Re: 1990 90 hp Force idle/gas problem?, please help

Sounds like you partially seized the motor due to overheating.It cooled down from sitting and unstuck itself. DON"T RUN IT ANY MORE OR YOU WILL DAMAGE IT !!!! The first thing you need to do before sinking any money into it is to do a compression check. If all cylinders are 125-145 psi and within 10 lbs hi to lo, then you can do some work to it.

First thing is a water pump kit. If it has been sitting, the impeller will be brittle and possibly broken. Next, get a fuel pump diaphragm. Lastly, take the carbs off, drop the bowls, clean out the gum and varnish from any passages that you can get at. Check the needle and seats for binding.

I just did all of the above on a Force 50 that had been sitting 5 years with no use. I was rewarded with it starting quickly, idling smoothly and pumping water nicely.

You should also change the gear oil in the lower.

You're going to need a manual, so order a Clymer.

 

[evil^^]

Re: 1990 90 hp Force idle/gas problem?, please help

It does circulate water okay. My stepfather took the carbs off tonight and found a plastic piece that was cracked, could that have been my problem? He is going to pick a new one up and replace it, I will ask him to get a impeller also. I haven't check compression yet, but would i have got the motor to go 30 mph with low compression? If the motor is partially seized is there any real fixing it then?

Thanks for your help

 

[bowhuntrrl]

Re: 1990 90 hp Force idle/gas problem?, please help

It's the partial seizure that I'm worried about ruining the compression !!! How do you know that it was circulating ?? Does it have an overheat alarm and have you tested it to see if it works ?? On the muffs, it's very hard to tell since these only have a mist coming out the 2 holes on the back of the motor anyways. It's not worth ruining the motor over the cost of an impeller or water pump kit. Mine needed the whole kit because the pump body was pitted. make sure to check your body and plate also. Sometimes you will get lucky with a partial seizure, that's why you really need to test the compression to determine where you are at.

 

[evil^^]

Re: 1990 90 hp Force idle/gas problem?, please help

If the compression is low what should i do next? I'm just getting as much infomation about my situation before I go back to work on it. When I ran the boat in the lake water squited out of the 2 hole in the motor. I will double check that, maybe it when out the last time I ran it. Thank you

 

[Frank Acampora]

Re: 1990 90 hp Force idle/gas problem?, please help

Tony: That engine should push a 15 foot boat at about 36-40 with 2 people in it. So at only 30 it is telling you something is wrong. Before you do anything, do diagnostic tests--Compression, spark , fuel delivery and water delivery. Assume everything is set incorrectly, get a Clymers manual and set everything to factory specs. Then if it still doesn't perform, start to troubleshoot.