j70tlcca hesitation/bog/stall off idle

[horiconducker]

I have run out of ideas so i thought i would post up on here. Motor had not been ran in five years. Has good compression 113- 115 psi on all three cylinders. I deleted vro by blocking off oil line on motor, replaced water pump, thermostat and rebuilt carbs with kits off of iboats. Did a complete link and sync according to oem manual. I have 2 problems, but im pretty sure they are connected and both fuel related. I have idle set at 700rpms in water and it idles ok, i think it could be smoother, it shakes a little at idle, but idles for 10mins. (my twin v4 crossflows are smoother at idle then this motor). On the lake If i advance the throttle to 800-900rpms it starts losing rpms and stalls within 15 seconds. After it stalls i have to use the primer to restart it. When it starts losing rpms i can keep it going with the primer, but its a fine line between flooding and running. My other situation is that it will bog and sometimes die out when doing a holeshot like pulling a skier from idle 700rpms. If i can get to it quick enough before it stalls primer will bring it back to life and away i go. If i advance the throttle to 1000rpms or so holeshot is great then.

 

[horiconducker]

Re: j70tlcca hesitation/bog/stall off idle

I have cleaned the carbs twice and soaked them overnight. I ran wire through all orfices and passages including the idle pickup tube. Floats are set parallel to carb body and pass the blow by test when inverted. Has brand new fuel tank lines and fittings. Other than these problems it runs great up to 5800rpm. i apologize for the length post. I am almost certain it is a fuel problem, i just dont know where to look anymore. thanks in advance for any insight ducker

 

[horiconducker]

Re: j70tlcca hesitation/bog/stall off idle

Any ideas? I did a little more trouble shooting today, I hooked up a clear hose on the fuel pump outlet to see if i had any air leaks, but i had none. I also noticed while running on the muffs today the idle would jump around a little bit, 100rpms or so, would go up for 10 seconds or so then back down. Was not really a pronounced sneeze, I have heard that on another boat i have.
With it running on the muff and intake off i plugged off the idle air bleeds one at a time, motor reacted the same with each orfice plugged, the rpms would drop some but would continue to run. This thing is really starting to frustrate me. thanks ducker

 

[horiconducker]

Re: j70tlcca hesitation/bog/stall off idle

I got to screw around with it again today. Spraying carb cleaner around to locate air leaks i noticed when i sprayed on the bottom side of carb where it mounts to intake rpms would drop indicating a leak. Was a little puzzled since i just put new gaskets on, but i went out and got 2 new sets of gaskets and doubled them up, but i still have an air leak there, any ideas how to seal it up? This is the only thing i can seem to find that is causing my lean condition. thanks ducker

 

[bigrockets]

Re: j70tlcca hesitation/bog/stall off idle

You may want to check for a hairline crack in the carb body where it mounts on the bottom side of that carb. After you installed the new gaskets did it still react to the carb cleaner spray by dropping RPM's?

 

[horiconducker]

Re: j70tlcca hesitation/bog/stall off idle

Yes even with the new gaskets on doubled up all three carbs still dropped rpms when sprayed with carb cleaner on the bottom side.

 

[horiconducker]

Re: j70tlcca hesitation/bog/stall off idle

Took the carbs off and checked for cracks, none found. There is a ring that is cast into the flange on the carb im assuming to help seal, it seem to be slightly thicker on the top where i have no leaks thinner on the bottom where i have the leak. I was thinking about sanding that ring down or off, but worried it might only leak worse then?