Hello,
I have a '79 100 HP Johnson V4 on my boat. It generally runs well but sometimes it's a bit finicky. Yesterday I think I had a clogged fuel port about 15 minutes into a trip around my lake. It was at wide open throttle and the RPM's dropped off then came most of the way back up but the motor ran rougher then it should have at 2500 on down to idle. I ended up checking everything. Took the carbs apart and cleaned them out. Checked for plug issues just in case I fouled out a plug. Even a compression test. All seems well with it right now on the hose but all this got me to thinking.
I have a "parts" motor I picked up on Craigslist last year for cheap. It is a 1988 Johnson 88 SPL and it is nearly complete (missing the motor internals). It has the newer primer style carbs (also slightly bigger venturi's). I have the intake manifold if that is different from mine as well as the front plate and cover which are different but I think I am missing the fuel pump and primer solenoid as well as most of the hoses that feed the tiny injection ports. I also have a cracked fuel inlet on one of the float bowls so that will need to be replaced.
Is this a worthwhile upgrade? My motor generally starts fine (unless I touch the priming bulb) but does seem to flood easier than I think it should. I would love better throttle response off idle and more air at wide open wouldn't be bad either. I have ran the larger carbs off the 115's before but took them off because the bushings were shot causing all sorts of air leak issues. Those 1 3/16 carbs ran nice above 4000 RPM but started and idled like crap.
If I do this is there anywhere where I could get a picture/diagram of the fuel hose routing?
I've got pics if needed.
I have a '79 100 HP Johnson V4 on my boat. It generally runs well but sometimes it's a bit finicky. Yesterday I think I had a clogged fuel port about 15 minutes into a trip around my lake. It was at wide open throttle and the RPM's dropped off then came most of the way back up but the motor ran rougher then it should have at 2500 on down to idle. I ended up checking everything. Took the carbs apart and cleaned them out. Checked for plug issues just in case I fouled out a plug. Even a compression test. All seems well with it right now on the hose but all this got me to thinking.
I have a "parts" motor I picked up on Craigslist last year for cheap. It is a 1988 Johnson 88 SPL and it is nearly complete (missing the motor internals). It has the newer primer style carbs (also slightly bigger venturi's). I have the intake manifold if that is different from mine as well as the front plate and cover which are different but I think I am missing the fuel pump and primer solenoid as well as most of the hoses that feed the tiny injection ports. I also have a cracked fuel inlet on one of the float bowls so that will need to be replaced.
Is this a worthwhile upgrade? My motor generally starts fine (unless I touch the priming bulb) but does seem to flood easier than I think it should. I would love better throttle response off idle and more air at wide open wouldn't be bad either. I have ran the larger carbs off the 115's before but took them off because the bushings were shot causing all sorts of air leak issues. Those 1 3/16 carbs ran nice above 4000 RPM but started and idled like crap.
If I do this is there anywhere where I could get a picture/diagram of the fuel hose routing?
I've got pics if needed.