OK, so I bought a 1989 black Max XR four 150. Compression is 125 across all cylinders I did the water pump and rebuilt the carbs and then fired it up. It started right up and idle perfectly.
I was not getting a tack reading and charging was nonexistent so I did my stater right away. It fixed the Tacc but not the charging so next I changed the voltage regulator/rectifier to the new upgraded all in one 20 amp. One from Buck shot racing.
Charging is better now 12.6 at idle and goes up to 13.2 around 4000 RPM
This entire time I am still having issues. The boat runs great to about 3/4 throttle and then it starts to bog down initially I thought it was fuel so I changed my fuel pump fuel lines and filters as well as the primer bulb
Even tried it with an auxiliary tank and a very short fuel hose to the motor. It was not the issue. I felt like ignition was slightly breaking down once you come off the throttle it picks back up
Tested the trigger and according to the manual, I’m supposed to have resistance and I do not so I changed the trigger aftermarket is only available. Put in the new trigger and the motor would barely start and ran like **** and would not shift out of gear without turning off, pulled the new trigger back out tested it no resistance so it’s also failed.
Put the old trigger back in out of curiosity. Motor ran good again, but still breakdown of ignition as what it felt like at high RPM
I changed four of the six ignition coils as they were older still no fix.
Need to know testing and where to look next I don’t really know how to determine which plug or coil is breaking down because it only happens at high RPM. How do I test it at high RPM And also how do I redo the timing on this motor? Could this all be trigger related?
I was not getting a tack reading and charging was nonexistent so I did my stater right away. It fixed the Tacc but not the charging so next I changed the voltage regulator/rectifier to the new upgraded all in one 20 amp. One from Buck shot racing.
Charging is better now 12.6 at idle and goes up to 13.2 around 4000 RPM
This entire time I am still having issues. The boat runs great to about 3/4 throttle and then it starts to bog down initially I thought it was fuel so I changed my fuel pump fuel lines and filters as well as the primer bulb
Even tried it with an auxiliary tank and a very short fuel hose to the motor. It was not the issue. I felt like ignition was slightly breaking down once you come off the throttle it picks back up
Tested the trigger and according to the manual, I’m supposed to have resistance and I do not so I changed the trigger aftermarket is only available. Put in the new trigger and the motor would barely start and ran like **** and would not shift out of gear without turning off, pulled the new trigger back out tested it no resistance so it’s also failed.
Put the old trigger back in out of curiosity. Motor ran good again, but still breakdown of ignition as what it felt like at high RPM
I changed four of the six ignition coils as they were older still no fix.
Need to know testing and where to look next I don’t really know how to determine which plug or coil is breaking down because it only happens at high RPM. How do I test it at high RPM And also how do I redo the timing on this motor? Could this all be trigger related?