New to this forum stuff, so here goes. I have a 93 Johnson 35 Jet that was recently giving to me. This is only the second boat I've owned so I'm still wet behind the ears on boat matters. First let me give you some back ground on my problem. It started about 4 weeks ago while fishing. The engine ran fine all day until time to go home. On the final start up for the day the engine did not sound or run right. I could only get half to three quarter throttle out of it all the way back to the dock.
When I got home I changed the plugs and wires and decided to try it out on the river. There was no change. I then began messing with the throttle linkage and carbs. Still no change finally I stopped at a boat shop and asked the mechanic. Within 10 minutes he had it diagnosed as a head gasket. So I ordered a new head gasket and I ordered a Clymer repair manual for guidance. I put the new head gasket on and readjusted all the throttle linkage to the specs in the repair manual.
I took the boat out for a test run and the engine started hard. This was also the case before head gasket problem. Once I got it running I put it in gear and put out of the no wake area then open her up. I would only get half throttle then it would flatten out, no more power. So I took it back to the guy who helped me before. He checked the timing and said it was in time. Pulled the Fuel pump and inspected diaphragm, it looked fine but was missing the gasket between pump and block. Put gasket in and tried it out with the same results. Mechanic recommended rebuilding carbs and pump. So I ordered the kits and rebuilt them with the help of a relative who is very mechanically inclined. I replaced all fuel hoses from tank to carbs and even the primer solenoid hoses. We hooked the engine up to a garden hose to dial it in somewhat before going to river. The engine was still hard to start but was able to get it to idle pretty good. So with timing light, spray bottle with fuel mix, repair manual, and tool box we headed to the river.
Backed in to the water started engine as usual playing with the primer bulb, choke and fast idle to get it to fire off. Finally got it running and adjusted idling by the manual. We took it out and it was still flat past half throttle. Hooked timing light up and found engine to be out of time. So we adjusted to Manual specs and tried it again. Engine ran outstanding all kinds of power but still have the hard starting and idling issue. We worked on the idling for about an hour and each time we got it adjusted right the engine would somehow change its idle and we would start over again and again like theirs an air leak somewhere. The engine is running rich and I can't figure out why. Sprayed fuel mix into each carb individually and engine would flood out. Pulled plugs and top one was black and wet. The bottom was not as black and wet. Primer bulb does get soft within about 6 to8 hours, don't know if that is normal. Could the primer solenoid be the issue? I'm sorry for this being so lengthy; just don't know what else to do. Here?s a recap of everything that?s been done to the engine.
Compression test good
Timing set
Carbs rebuilt
fuel pump rebuilt
all new fuel lines and filter
linkage set by manual
spark good
new plugs and wires
fresh gas in clean tank
When I got home I changed the plugs and wires and decided to try it out on the river. There was no change. I then began messing with the throttle linkage and carbs. Still no change finally I stopped at a boat shop and asked the mechanic. Within 10 minutes he had it diagnosed as a head gasket. So I ordered a new head gasket and I ordered a Clymer repair manual for guidance. I put the new head gasket on and readjusted all the throttle linkage to the specs in the repair manual.
I took the boat out for a test run and the engine started hard. This was also the case before head gasket problem. Once I got it running I put it in gear and put out of the no wake area then open her up. I would only get half throttle then it would flatten out, no more power. So I took it back to the guy who helped me before. He checked the timing and said it was in time. Pulled the Fuel pump and inspected diaphragm, it looked fine but was missing the gasket between pump and block. Put gasket in and tried it out with the same results. Mechanic recommended rebuilding carbs and pump. So I ordered the kits and rebuilt them with the help of a relative who is very mechanically inclined. I replaced all fuel hoses from tank to carbs and even the primer solenoid hoses. We hooked the engine up to a garden hose to dial it in somewhat before going to river. The engine was still hard to start but was able to get it to idle pretty good. So with timing light, spray bottle with fuel mix, repair manual, and tool box we headed to the river.
Backed in to the water started engine as usual playing with the primer bulb, choke and fast idle to get it to fire off. Finally got it running and adjusted idling by the manual. We took it out and it was still flat past half throttle. Hooked timing light up and found engine to be out of time. So we adjusted to Manual specs and tried it again. Engine ran outstanding all kinds of power but still have the hard starting and idling issue. We worked on the idling for about an hour and each time we got it adjusted right the engine would somehow change its idle and we would start over again and again like theirs an air leak somewhere. The engine is running rich and I can't figure out why. Sprayed fuel mix into each carb individually and engine would flood out. Pulled plugs and top one was black and wet. The bottom was not as black and wet. Primer bulb does get soft within about 6 to8 hours, don't know if that is normal. Could the primer solenoid be the issue? I'm sorry for this being so lengthy; just don't know what else to do. Here?s a recap of everything that?s been done to the engine.
Compression test good
Timing set
Carbs rebuilt
fuel pump rebuilt
all new fuel lines and filter
linkage set by manual
spark good
new plugs and wires
fresh gas in clean tank