"72 65ESL won't gradually throttle up

[Chaz1]

My 1972 65hp ESL won't throttle up with a little throttle increase at a time. It idles fine and will usually take off if you "punch it". Sometimes it hesitates before taking off if you punch it, but usually takes right off. Once it gets up and planes out you can back off the throttle and it's fine. There's just that dead spot just above a fast idle.

Now if you try to gradually throttle up, it bogs out. I'm thinking a possible fuel pump problem. Any thoughts are greatly appreciated.

 

[jay_merrill]

Re: "72 65ESL won't gradually throttle up

Mine does the same thing but at a higher rpm. It has a spot at about 2/3s throttle where it sort of "takes off." It doesn't run badly at any point but there is a definate surge at the point where I am talking about. Its almost as if "a 4th cylinder" had kicked in. I've never been able to figure out just what causes this but I am thinking it may have to do with the way the timer base advances the spark.

 

[Chaz1]

Re: "72 65ESL won't gradually throttle up

No Jay, what I am saying is that my motor dies if I try to slowly throttle up from idle. It just quits. The only way to keep it from stalling is to go from idle to WOT . There is no way to gradually increase the throttle. I can't go from idle to say....1/4 throttle or 1/2 throttle. It's WOT or kaput!!!! And like I said, once I "punch it" and it takes off and then I can back it down to whatever engine speed I want. Frustrating.

 

[tashasdaddy]

Re: "72 65ESL won't gradually throttle up

Chaz1, sound like you need to linc n sinc. your motor. timeing and carb not working together.

 

[Chaz1]

Re: "72 65ESL won't gradually throttle up

Is this someting that I could do myself or should I take it to the shop. (50 miles away to the closest marine shop willing to work on the old girl

 

[jay_merrill]

Re: "72 65ESL won't gradually throttle up

Check page 4-12 of your service manual for the procedure to sync the carbs - its entitled "SYCHRONIZING CARBURETOR AND DISTRIBUTOR LINKAGE"

If you don't have the manual, PM me with an email addy and I will scan/send the page to you.