J200TXESM 90mod bogging down as it runs

[MagnumGill]

New to this forum:
I have a J200TXESM 90 model that has given me fits.
Acted like it was running out of gas;
changed bulb and line, nope,
replaced VRO, nope
replaced power pack, nope
replaced stator, nope
reglued 2 loose flywheel magnets, nope
The only thing i have not replaced is the vacuum switch on the VRO and the trigger.
It cranks up fine, runs good but has a random skip on hose or in water.
Timing is 18-20 at WOT. 4-6 at idle.
Compression is 76 on all 6 cylinders. I know its low but it ran 5000rpm and 42mph with that same comp before all this started happening.
I need to get a good service manual for this engine, any certain one to get that will show testing components the best?

thanks,
Michael

 

[Bosunsmate]

Re: J200TXESM 90mod bogging down as it runs

Hello
Thats a painful post to read, so many expensive parts replaced and no success.
You could try running it at night and see if its arching from anywhere causing the miss.
How oftens the miss?
Im not sure about service manual sorry

 

[MagnumGill]

Re: J200TXESM 90mod bogging down as it runs

It has been a painful and costly 6months trying to figure it out with 5 different "good" mechanics in the mix. I've had boats all my life and never had one to stump me like this.
I'm in the process today of bypassing the OIL part of the NEW VRO pump and use a 6gal aux tank. I think it may be the switch that is one the vro that senses the vacuum and telling it to go into "Slow Mode" when it dont need to. Redone the oil lines primed and all as instructed with no luck.
Any other ideas are welcome...

Michael

 

[Bosunsmate]

Re: J200TXESM 90mod bogging down as it runs

One other idea, low compression can affect fuel pumping so try priming manually with bulb to see if that helps

 

[MagnumGill]

Re: J200TXESM 90mod bogging down as it runs

Yep, the low compression has been on my mind but it baffled me because it ran great for a while after I got it with that same compression.
However, I may have got a fix for it, X my fingers. I a 6gal with premix to the pump, took the oil line off and caped it, took the vacuum switch out of the line and undid the wires. It ran great for at least 20-30 min on the hose. Didnt have the spitting and cutting out like it did before. I think it has to be that switch trying to put it in slow mode but it's not giveing an alarm but ever now and then.
Going to the lake in the morning, will let you know.
Any more suggestions are welcome.
Thanks
Michael

 

[MagnumGill]

Re: J200TXESM 90mod bogging down as it runs

Well took the vacuum switch out, connected fuel line streight to vro, disconnected oil line from vro and plugged it, got my 6gal tank with premix, ran all that and 4 more gals and she ran better than she ever has. Got 44mph at 5200rpm. from what I hear that's about as good as it gets with this WellCraft Walkaround with a 200hp. Looks like I will be mixing my gas in my big tank now. I know it's safer but really wanted the vro to work. I just dont like mixing 85 to 100 gals with oil at a time.

 

[Bosunsmate]

Re: J200TXESM 90mod bogging down as it runs

Thats good news and good to hear what 76psi can do to