I have a 1991 90hp v4 crossflow that I cannot solve.
I added a video to help understand the problem.
A few months ago i bought this motor. The compression readings are from 115psi to 108psi. Hasn’t changed since I purchased it.
While out one day it picked up some tree bark from logging activity and partially covered the intake. The alarm was removed from the controls, and the motor overheated.
I brought it home and ran it in the tank. It was tough to start up but it did. I then checked the coils and turns out 2 had an open loop and 2 were lower in the 200-400 ohms on the primary. I decided to replace all four coils.
The motor turns over but after 10 seconds it starts to surge. I placed my hand over the carbs and there is nothing blowing back towards my hand.
I then checked the spark on all four cylinders and it’s a nice blue spark.
Since I dont have a dva, I resorted to swapping out the power pack. I did this after testing resistance on the stator and the timing base. All within spec.
While testing the stator I discovered that the rectifier had blown up from the over heating. I replaced that, and that is working properly.
I then took apart my carbs and cleaned them twice. Still nothing. I then used propane and carb cleaner on gaskets that maybe have a vacuum leak, still nothing. I tested the fuel pump and that is good.
The link and sync is good.
Any suggestions?
I added a video to help understand the problem.
A few months ago i bought this motor. The compression readings are from 115psi to 108psi. Hasn’t changed since I purchased it.
While out one day it picked up some tree bark from logging activity and partially covered the intake. The alarm was removed from the controls, and the motor overheated.
I brought it home and ran it in the tank. It was tough to start up but it did. I then checked the coils and turns out 2 had an open loop and 2 were lower in the 200-400 ohms on the primary. I decided to replace all four coils.
The motor turns over but after 10 seconds it starts to surge. I placed my hand over the carbs and there is nothing blowing back towards my hand.
I then checked the spark on all four cylinders and it’s a nice blue spark.
Since I dont have a dva, I resorted to swapping out the power pack. I did this after testing resistance on the stator and the timing base. All within spec.
While testing the stator I discovered that the rectifier had blown up from the over heating. I replaced that, and that is working properly.
I then took apart my carbs and cleaned them twice. Still nothing. I then used propane and carb cleaner on gaskets that maybe have a vacuum leak, still nothing. I tested the fuel pump and that is good.
The link and sync is good.
Any suggestions?