1984 Force 125 Carb Sync

[ljshein]

I feel stupid becasue I have the seloc book and I've read it several times but I just can't seem to get this right.

Is there any decent documentation that explains exactly how to sync up the carbs on a 1984 - 125?

I've cleaned the carbs and replaced the needle valves, I've followed the instructions on lining up the linkage and the needle valves but it's still not right.

The idle is inconsistent at best. Either I set it up to 1100 RPM and it's stays but I feel like I'm slamming the transmission or I set it lower and it stalls once it's warm.

Between 1500 & 2500 RPM the engine vibrates and sounds like a giant vacuum cleaner.

Above 3000 RPM all the way up to 5000 RPM, smooth as can be.

any push in the right direction would be a big help!

thanks!
Jeff

 

[Frank Acampora]

Re: 1984 Force 125 Carb Sync

From what I've heard, don't feel stupid: Seloc is crap. Get the factory manual or a Clymers manual.

Couple of hints: RPM should be 700 in forward gear, in the water. Any less and it will be unreliable.

with the engine in neutral. set the idle stop screw to about the center of its travel. Then see if the 2 marks on the throttle cam line up with the black roller on the carb. If they do not, remove the ball joint on the tower and set the rod so they do. The black roller is on an eccentric screw, if it does not touch the cam, loosen the nut slightly and turn the screw until the roller just touches. Now, loosen the screw on the aluminum carb tie bar and let both carbs close. Then tighten the screw. Now, both carb butterflies should be closed. Move the control to full throttle and se if the butterflies are substantially horizontal and equal--they should be.

Now it is time to check timing. with the boat in the water, at wide open throttle check to see that timing is 30 deg before TDC. If not, stop the engine and adjust the link right under the flywheel. DO NOT ATTEMPT WHILE ENGIN IS RUNNING! To do so invites painting the engine red and joining the 9 finger club. Shortening the link retards the timing.

Once the timing is correct, set the idle stop screw for the proper idle RPM. Now, it is time to adjust those famous idle mixture screws. Start with 1 1/4 turns out from lightly seated. Gradually lean them out 1/8 turn at a time until the rpm which should have been rising, drops off. Then richen them until the engin sags. The correct setting is the average. DO not under ant circumstances lean past 3/4 turn out less that that is begging to melt a piston. No matter how the idle is, stay at least between 3/4 and 7/8 turn out from lightly seated. If you accelerate slowly, It has been my experience that every Chrysler and Force engine I have gets very rough right around 1500-2000 RPM then smooths out again--seems to be the nature of the beast.

That should get you somewhere close to where you want to be.

 

[ljshein]

Re: 1984 Force 125 Carb Sync

Frank,

Thanks for the excellent advice. The month of April was not great for boating here in Atlanta so I haven't been paying attention to the board. I was back out this past weekend. I found the bottom Carb was leaking really bad around the fuel bowl gasket so as soon as the parts come in for that, I will most definitely follow your excellent advice.

Thanks!
Jeff