texasippian
Cadet
- Joined
- Sep 12, 2019
- Messages
- 12
First time posting, so I will try to make some sense of what's going on with my motor. It's a 91 Johnson 150 (TJ150SLEI) crossflow that I purchased July 3, 2019. I was told it was a great running boat (guy had video from June of him running it) and it cranked and ran fine on muffs.
I get the boat home, fix it up how I want it for bass fishing, launch it in the lake, and the boat idled fine but would not accelerate past 6mph (2k rpms). Eventually, the boat would just die every time I put it in gear. I immediately tried to contact the seller and guess what?!?! No response.
The first thing I did was remove all three carbs, clean all jets with carb cleaner and used a piece of steel wire to go through the jets. I changed all gaskets in the carbs, adjusted the floats per the specs in the FACTORY manual. Still, no improvement.
Next, I drained all fuel and added premium fuel with ethanol treatment added. No better. I also did a de-carbonizing procedure and replaced the plugs afterwords, no change.
Noticed that the previous owner had an electric inline fuel pump in place, not sure why, but I removed it, and retro-fitted to the dual fuel pump set up (pre VRO). Verified that after I connected new fuel pumps that they were working, still, no better.
Compression is between 84 and 87 on all cylinders. Which I know seems low, but per the manual as long as they are not varied greater than 15 psi, it should be fine. I have not done a leak down test, as I do not have the equipment.
Two of the ignition coils look like a rat had chewed on them, so I replaced them. I have two more coils with some damage to the housing, but have not replaced. However, I have checked them all and they are 'ohming' out within spec. Should I just change them anyway? Plug wires seem to be ok, but if I replace coils, I will replace wires too.
I also checked the flywheel and found the key was busted to heck. I replaced the key (OMC) and torqued the flywheel to spec. Verified timing was still correct (at idle). Still not running right.
I am getting spark to all cylinders, have checked my idle timing and adjusted, performed link and sync procedure, and am in the process of troubleshooting the CDI system step by step. I have verified that my peak voltage readings are within spec on the charge coil and sensor coil (timing base). Ohmmeter test are also OK. I am now checking the power pack, and when looking at the output to the ignition coil it says it should be 175V or higher, I am only getting 110V (I am quite certain the battery is fully charged) at all 6 'orange' leads going to the primary post on the coils. COULD A FAULTY POWER PACK BE THE CAUSE OF THE ENGINE DYING WHILE UNDER LOAD?
I am at my wits end. I have done about all I am capable of (except change all of my small fuel lines going to carbs/crankcase). Could it be an issue that maybe I am getting too much air due to a leaky fuel line? Head gasket leaking? Any help is greatly appreciated. This forum has been a massive help so far, but I am throwing a hail mary and hoping you guys that are much better than this can help me. Thanks a ton for reading this incredibly long post.
Respectfully,
Ryan
I get the boat home, fix it up how I want it for bass fishing, launch it in the lake, and the boat idled fine but would not accelerate past 6mph (2k rpms). Eventually, the boat would just die every time I put it in gear. I immediately tried to contact the seller and guess what?!?! No response.
The first thing I did was remove all three carbs, clean all jets with carb cleaner and used a piece of steel wire to go through the jets. I changed all gaskets in the carbs, adjusted the floats per the specs in the FACTORY manual. Still, no improvement.
Next, I drained all fuel and added premium fuel with ethanol treatment added. No better. I also did a de-carbonizing procedure and replaced the plugs afterwords, no change.
Noticed that the previous owner had an electric inline fuel pump in place, not sure why, but I removed it, and retro-fitted to the dual fuel pump set up (pre VRO). Verified that after I connected new fuel pumps that they were working, still, no better.
Compression is between 84 and 87 on all cylinders. Which I know seems low, but per the manual as long as they are not varied greater than 15 psi, it should be fine. I have not done a leak down test, as I do not have the equipment.
Two of the ignition coils look like a rat had chewed on them, so I replaced them. I have two more coils with some damage to the housing, but have not replaced. However, I have checked them all and they are 'ohming' out within spec. Should I just change them anyway? Plug wires seem to be ok, but if I replace coils, I will replace wires too.
I also checked the flywheel and found the key was busted to heck. I replaced the key (OMC) and torqued the flywheel to spec. Verified timing was still correct (at idle). Still not running right.
I am getting spark to all cylinders, have checked my idle timing and adjusted, performed link and sync procedure, and am in the process of troubleshooting the CDI system step by step. I have verified that my peak voltage readings are within spec on the charge coil and sensor coil (timing base). Ohmmeter test are also OK. I am now checking the power pack, and when looking at the output to the ignition coil it says it should be 175V or higher, I am only getting 110V (I am quite certain the battery is fully charged) at all 6 'orange' leads going to the primary post on the coils. COULD A FAULTY POWER PACK BE THE CAUSE OF THE ENGINE DYING WHILE UNDER LOAD?
I am at my wits end. I have done about all I am capable of (except change all of my small fuel lines going to carbs/crankcase). Could it be an issue that maybe I am getting too much air due to a leaky fuel line? Head gasket leaking? Any help is greatly appreciated. This forum has been a massive help so far, but I am throwing a hail mary and hoping you guys that are much better than this can help me. Thanks a ton for reading this incredibly long post.
Respectfully,
Ryan
