1998 50 HP SPL timing advance vs throttle issue

[Jdbenedi]

The motor has had issues fouling plug since we purchased it 2nd hand. Rebuilt the carbs and checked the timing and it was so far beyond ATDC that in order to bring it to 0-2 ATDC at idle we needed to shorten the control arm so short that now when we advance the throttle the timing advance hits a stop before the throttle advances to WOT. At the max we are reading 18-20 BTDC on the timing. In order to get the timing correct we had to shorted the control arm to be close to around 1-1/2" long

The motor has never idled better and it seems to be operating much better at the correct idle timing but we are no longer able to operate the throttle properly because the timing advance is reaching its upper limit. Any suggestions?

I am going to pull the flywheel tomorrow and see if someone messed up the timing control at some point. Has anyone ever seen an issue like this?

 

[racerone]

Timing on these motors does not go out of adjustment over the life of the motor.-----Unless an owner messed it up.------You only set maximum timing advance.-----Timing at idle looks after itself.-----OR idle timing is the point where throttle plates open.-------A proper manual will help you.-----Or run to a shop, explain what you did with adjustments.