we have a 1989 70hp johnson. just to start we posted about two weeks ago about our ongoing over heating issue and th motor going into slow mode. The motor was running great and has been runnign at normal temps even now. we thought we had bad gas again as we have had several doses of bad gas. so we switched to good new gas and it seem to run fine on muffs. put it int he water last night and it was a little hard starting but once it got started it idled ok and idled for probably 10 minutes until we got out of the dock and mantee zones. as soona s we hit the throttle it reved right up and ran fine. so we ran it at about 3000rpm for about 15-20 min and it ran great. we slowed down and it came down to idle and we pulled up to a fishing spot. we fished for about 45 min or so it was about 65 out last night so the motor cooled pretty fast. anyways after fishing we tried to start and again would not start. i took the cover off and while cranking i advanced the throttle and turned the manual knob on the primer to about half way and it started. the tach said it was runnign about 2000 rpm. there was a good amount of smoke and it deff was not running great almost like it missing a cylinder. above 2000 it smoothed right out. once above 2000 i had to turn the manual primer knob back to normal off position and motor ran great back to the dock again it idled to the dock and deff ruff but it did stay running long enough to get on the trailer. we pulled it out and went to clean the boat and flush the motor and it started right up on muffs and run at about 1600 rpm for about 5 min no prob. it would spit and sputter a little but not terrible but it would not idle any lower than that or it would stall.
now here is a list of stuff we have done to it within the last two months. we have rebuilt the carbs about 2 months ago with omc kits. as im sure you guys know there is not much to these carbs as they are needle less. about two or three weeks ago we removed the carbs again and cleaned them out at someones recomendation for another issue. I have replaced the carb linkage arm, rebuilt the fuel pump, replaced the primer selonoid top (oops) and diaphram, replaced the plugs, installed a fuel/water seperator,replaced all fuel line, i believe that is all we have done in relationship to fuel issues. on a side not we did removed the exhaust/water side cover and cleaned a ton of scale out and installed new omc gasket, removed head and cleaned scale out installed new omc gasket. and any other part i replaced i used all omc parts.
also forgot to mention that we have had several bad (water) fuel issues and did after the problem this weekend switch from our installed fuel cell which is in the front of the boat to regular portable 6.5 gallon marine tanks that are in the back of the boat.
now here is a list of stuff we have done to it within the last two months. we have rebuilt the carbs about 2 months ago with omc kits. as im sure you guys know there is not much to these carbs as they are needle less. about two or three weeks ago we removed the carbs again and cleaned them out at someones recomendation for another issue. I have replaced the carb linkage arm, rebuilt the fuel pump, replaced the primer selonoid top (oops) and diaphram, replaced the plugs, installed a fuel/water seperator,replaced all fuel line, i believe that is all we have done in relationship to fuel issues. on a side not we did removed the exhaust/water side cover and cleaned a ton of scale out and installed new omc gasket, removed head and cleaned scale out installed new omc gasket. and any other part i replaced i used all omc parts.
also forgot to mention that we have had several bad (water) fuel issues and did after the problem this weekend switch from our installed fuel cell which is in the front of the boat to regular portable 6.5 gallon marine tanks that are in the back of the boat.
