Why does V6 150hp 1991 blackmax bog down and stall on acceleration?

[Moretoyman]

Just taken boat on lake after new plugs and tune up. Set idle and max timing according to manual . Soon as in she hit the water it wouldnt idle fast enough. Sped up idle and then it bogged down and stalled after it reached about1500 rpm. I noticed that i had to make a lot of adjustment to reach the 21 degrees BTDC setting recommended for cranking max timing . the trigger link rod is correct length but i had to adjust the stop screw signifigantly to set crank timing at 21degrees. Now the link rod end is half way across movement gap with engine at idle. All settings were done with water supplied by hose muffs. Is stalling and bogging down a symptom of mtoo much retardation or could this be a fuel problem. A couple of fellow boaties who watched me start and stall several times until i idled it back to trailer opined that this was due to bad spark plugs but I dont think so cos i just replaced and tested them all.
Any advice would be welcome.

 

[Faztbullet]

Re: Why does V6 150hp 1991 blackmax bog down and stall on acceleration?

Sounds like you didnt disconnect the idle stabilizer or arm was not fully pulled to rear when you set max timing. The idle timing is really a starting place and doesnt need to be spot on. Also the roller gap if to tight (I set all my customers V motors at 3/16 gap) and weak fuel pressure can cause this. Go back thru the sync and link as something is off..

 

[Moretoyman]

Re: Why does V6 150hp 1991 blackmax bog down and stall on acceleration?

yep I think that it could be not pulling the arm back properly but im going thru the whole rigmarole again in a couple of days time and will post the results. Idle stabilizer was dis and re connected but how reliable are they? do they regularly give trouble. anyhoo thanks for yur advice

 

[Faztbullet]

Re: Why does V6 150hp 1991 blackmax bog down and stall on acceleration?

Disconnect it and throw it away, been many a mota popped by these acting goofy.

 

[Moretoyman]

Re: Why does V6 150hp 1991 blackmax bog down and stall on acceleration?

Thanks very much for your input, its what makes life a lot easier for thickheads like me.
Redone sync and boy was the max timing out of adjustment. Set up as per wkshp manual and disconnected permanently the idle stabiliser. You say you set roller at 3/16 gap but that seems pretty large, not a typo is it, manual says just touching and i,m thinking you set it larger to allow timing to move just prior to carb throats opening . Muffs on first thing in morning to set initial idle and then of to the lake to test out and final adjust all settings.
Ill post results in next few days. Once again thanks for your advice.:happy:

 

[Faztbullet]

Re: Why does V6 150hp 1991 blackmax bog down and stall on acceleration?

No typo.....

 

[Moretoyman]

Re: Why does V6 150hp 1991 blackmax bog down and stall on acceleration?

took to lake and reset idle and max timing in water also set cam at 1/8th gap .Max timing needed less advance to not bog down. drained fuel as it was a coulpe of months old and adjusted carb idle mixture. Its now set to idle at 800rpm in forward and neutral and accelerates well without bogging down . So thanks to you advisors i,m of to do some well earned fishing and maybe have a few beers. CHEERS.