200 venom idle and runability

[Johnnyl30y]

I recently traded for a boat with a blown 1995 johnson 200hp venom motor. I did a powerhead swap and have struggled to get it running 100% right. The idle is very inconsistent but usually sputters out and dies. It sometimes struggles to get on plane, and only once I have got it to hit 5700 rpms and felt like it was running like it should. Things I have done in the last few weeks: swapped powerhead rebuilt carbs, installed new reeds, replaced regulator, replaced 2 recirculation valve ripples (check valves weren't working), compression check varied from 99-108 across all cylinders, new spark plugs, new fuel pump, all new fuel lines and primer bulb, removed anti siphon valve at tank. I may be forgetting something, but that about covers it. The intermittent issues are driving me nuts. 5700 rpms and 57 mph one day (got right up on plane), 4900 and 50 mph the next. Idles pretty good one day, not the next. Always starts hard first time off the trailer. Any ideas of anything I've missed would be much appreciated!

 

[racerone]

Pushing the key in and holding it in while cranking for cold starting ?-----Does spark jump a gap of 3/8" on all leads?-----Water in fuel ?

 

[Johnnyl30y]

Fuel is good, been through multiple tanks same response. I do hold the key in on cold starts. One weird thing on that, that I've noticed. It seems the starter motor wont stay engaged for long usually. I tried the reeves method to set the max advance on the timing and couldn't fo it for that reason. I will re-test spark for 3/8" next.

 

[Johnnyl30y]

So I do have good spark on all cylinders. One thing that i don't understand though is I cannot get the wot spark advance set to spec. I have the adjustment screw as far as it can go and am still 4-5 degrees too retarded. I'm guessing this may be why I'm only hitting around 48-50 mph and not getting on plane very quickly?

 

[dingbat]

So I do have good spark on all cylinders. One thing that i don't understand though is I cannot get the wot spark advance set to spec. I have the adjustment screw as far as it can go and am still 4-5 degrees too retarded. I'm guessing this may be why I'm only hitting around 48-50 mph and not getting on plane very quickly?

Have you checked the location of the timing pointer per the manual?

Done a complete link and sync?

 

[racerone]

Spark maximum advance is set for life of the motor.----Normally needs no adjustment.----Make sure it is correct.

 

[Johnnyl30y]

Have you checked the location of the timing pointer per the manual?

Done a complete link and sync?

I had to make my own pointer. The original was damaged during the powerhead swap. So I made one, mounted it, and found TDC by the book. It does not line up with TDC on the flywheel markings, so I made my own mark. I have done the link and sync to this point, that's why I was checking the timing.

 

[Johnnyl30y]

Spark maximum advance is set for life of the motor.----Normally needs no adjustment.----Make sure it is correct.

I had to do a powerhead swap, and transfer and mix and match electrical components from the two motors, thats why I am trying to reset it now.

 

[dingbat]

So I made one, mounted it, and found TDC by the book. It does not line up with TDC on the flywheel markings, so I made my own mark.

 

[racerone]

Checked the flywheel key??