I have been working on my 1990 40HP johnson for some time now.
To date, I have rebuilt the carbs, and gone throught them twice.
I have correctly set the floats, & sinc.
I termirned that the VRO was over oiling at idle, and converted it to a pre-mixer.
I determined that the DCI was double firing at idle sometimes and replaced it with the updated unit.
Here is my current issue, the engine will idle great now, but seems to misfire around 2500 RPM or more. I checked the plugs, and they look great, and identical. On the previous trip I determined that I had mis-adjusted the advance. The engine was idling great all day trolling, but it on one cyln.
I reset the advance at idle. On my next trip, it idled on both cylinders, but had the same issue above 2500RPM. It kind of sounds like it's running under water. This time I checked the fuel flow, it was not fuel starving. But when I got home I found the advance cam was broken. I broke it while installing the new ignition and bonded it back togethter. It failed on the 2nd trip.
My question is How can I tell if the CDI is in SLOW mode. It might be defective. I did pull the bn wire on the last trip, no help. When I got it home I fired it up on the hose, it was idling OK on both cylinders, I checked the timing, it was off. Then I noted that the cam was broken. The new part will be here in about a week. Is there anyway to prevent SLOW the mode? Will tying the brown wire to +12V prevent it? It sould be unrelated, defective, or an EMI problem. This problem did not exist prio to the CDI update, but I'm not sure the timming was set, & the advance working on the last two trips.
Thanks
To date, I have rebuilt the carbs, and gone throught them twice.
I have correctly set the floats, & sinc.
I termirned that the VRO was over oiling at idle, and converted it to a pre-mixer.
I determined that the DCI was double firing at idle sometimes and replaced it with the updated unit.
Here is my current issue, the engine will idle great now, but seems to misfire around 2500 RPM or more. I checked the plugs, and they look great, and identical. On the previous trip I determined that I had mis-adjusted the advance. The engine was idling great all day trolling, but it on one cyln.
I reset the advance at idle. On my next trip, it idled on both cylinders, but had the same issue above 2500RPM. It kind of sounds like it's running under water. This time I checked the fuel flow, it was not fuel starving. But when I got home I found the advance cam was broken. I broke it while installing the new ignition and bonded it back togethter. It failed on the 2nd trip.
My question is How can I tell if the CDI is in SLOW mode. It might be defective. I did pull the bn wire on the last trip, no help. When I got it home I fired it up on the hose, it was idling OK on both cylinders, I checked the timing, it was off. Then I noted that the cam was broken. The new part will be here in about a week. Is there anyway to prevent SLOW the mode? Will tying the brown wire to +12V prevent it? It sould be unrelated, defective, or an EMI problem. This problem did not exist prio to the CDI update, but I'm not sure the timming was set, & the advance working on the last two trips.
Thanks
