Just aquired a 120 hp Force. Serial # OE012673. From a little internet research, I think it is a 1993 model. There seems to be some conflict on some of the info I found but it seems to be a 1993 and not a 1995 as one chart indicated. There appears to be 6 models offered in that year and havent found anything that tells how to determine which one is which. Anyway it wont crank. Cleaned the carbs first, found a little trash but otherwise looked pretty clean already. All parts have good flow through them and the floats are clean and seem to be sealing off. Got it on Saturday and did not have anywhere to get carb kit on short notice. I swapped the needled valve from bottom to top because the top looked better and the bottom seems to be flooding out. The bottom two cylinders are getting a lot of gas. I can take the plugs out and turn it over and gas blows out of the bottom two cylinders. I cant see it blow out of the top two cylinders. When I turn it over gas runs out of the front of the lower carb. But the float seals off if I lift it up with my finger and pump the bulb on the gas line. I dont understand how the choke works on this engine, but it clicks when you push the key in. Also the temp warning buzzer is going off when the key is turned on, looks like it is bad. The wire right at the base of the sensor looks kind of shorted. Does this sensor have a kill feature to it? It doesnt appear too. Can I unplug it to shut it up for now? I seem to have good compression (tester walked off and will have to go get another) and do have blue fire on all plugs. Need to see if this thing is gonna run before we made the final deal on it. Boat was sitting up for a while and a friend bought it. The kid puts gas in it and takes off for the river. Boat cranks and runs for a short way and of course it needed water pump, so they shut it down and trolled back. He had an impeller installed and then the cranking problems started. It occasionally hits a little and will backfire some times. I checked the gas and found out it has some water in it, so I hooked it to a clean tank and cleaned carbs good. Got compession and gas and fire but no crank, what now???
ok compression is not good. First, do you check compression with other plugs in or out? with the other three plugs in, the top three cylinders only have about 55 lbs, with the plugs out they have about 65. the bottom checks at about 125. I think the boys must have run it too hot before they had somebody to put an impeller in it. It will still need a carb kit but I think its gonna be a little more complicated than that. oh and the serial number is the only number on the tag. How expensive is it gonna be to build this thing? Is it worth the trouble or would it be cheaper to find another motor? Is the manual good enough to walk us through a rebuild? I work on a lot of junk but boat motors with alot of electronics are not my thing. My husband is pretty good on autos but like me newer style boat motors not so much. Wish I had a manual for it. But dont want to invest in anything else until we decide if its worth trading for. Know an excellant Merc man but it takes him forever to get to one.