Rochester 2bbl bogging under load

[freelunch]

Re: Rochester 2bbl bogging under load

Yea, it is a new problem. I recently had the cylinder head off for hardened exhaust valve seats and a valve job. My boat is an 18 ft sea ray bowrider tri hull. I never had this problem before the head came off. However, the installation was done competently and I doubt that is the issue.

 

[FreeBeeTony]

Re: Rochester 2bbl bogging under load

Are you sure all 6 cylinders are firing?
Are the valves adjusted properly?

 

[Haut Medoc]

Re: Rochester 2bbl bogging under load

You might have mentioned that you had the head off a little earlier in the post.....
A vacuum test might reveal something......​

 

[freelunch]

Re: Rochester 2bbl bogging under load

The valves are backed down from zero lash to specs and it was done with the crank in the proper place.
I can double check the fire on all the cylinders i suppose. . . ugh, i can hardly remember when having a boat was fun. . .

 

[FreeBeeTony]

Re: Rochester 2bbl bogging under load

I would re-adjust the valves while running at normal operating temp......just a hunch.

 

[roadrash]

Re: Rochester 2bbl bogging under load

I have the same problem with my 3.7 at the moment. Just put a tune up in her and it runs fine with muffs but under power starts to bog on plain. so dwell meter time tomorrow.

 

[roadrash]

Re: Rochester 2bbl bogging under load

I couldnt get my boat dialed in matter what. Had the same problem, ran good on muffs but not good under power.Finally got fed up and called some one i trusted in the business. Turns out that theres a switch(im sure some one knows the name of it on here) that cuts 2 clynders out on my 4 cylndr when shifting. bad switch. problem solved, rammed around this afternoon, no more glithches.

 

[snlgraham]

Re: Rochester 2bbl bogging under load

Yep, I had the exact same issue with the cut out switch. I have the rochester 2bbl carb. I rebuilt it(messed up the float). I checked the dwell. I checked fuel. I checked everything, so I thought. I had the carb and timing so out of adjustment that I couldnt get it running. Was the stupid little cut out switch. Or in my case the throttle cable that moves the switch was not working properly. I am sure someone here can tell you how to bypass this switch so you can verify if that is the problem. I am not a pro but I am sure a pro would check to see if the cut-out switch was good.
Good luck.....I had to take mine to a shop. Man that hurts.

 

[snlgraham]

Re: Rochester 2bbl bogging under load

Maybe it is called the "interupt switch" not the cut-out switch?
What-ever....

 

[freelunch]

Re: Rochester 2bbl bogging under load

Yea youre right, the shift interupter switch and the throttle position switch both can stop the ignition from operating at the coil as they hook up to the negative terminal on the coil. However, to locate the problem I ran a hot lead from the + terminal on the batt to the + on the coil, then ran my distributor wire to the - coil hookup. With this configuration those switches are bypassed. Then I tried remote cranking it and still didnt have any luck.

 

[sabastianunf]

Re: Rochester 2bbl bogging under load

I would listen to haut and bondo. If you didn't have problems with it before the work was done on the head I would look at it. Also if you had the carb off while the work was being done to the head and the fuel was drained out then it could also be the problem.