High idle after running? Secondaries sticking?
 

I've been struggling with my idle climbing to 1100-1300 r's after running the throttle. I've been having to shut the engine off and restart to get it back into gear. It seems to me like it has to be the secondaries sticking open a little, if i push down on the rod the idle slows. I'm not sure how to correct this though? not much of a carb guy so be patient but should i bend the rod coming for the primary to help put more pressure on the secondary shaft to help close? If the rod binding internally and need to be disassembled? Any other correction for this symptom? Thanks in advance guys

Oh, it a 950 Holly btw.

Could also be that your air screws are set too rich, and you have the idle set to compensate. After running at higher rpms the engine cleans out and is running leaner, and your idle stays high until the rich mixture catches back up to slow it down.

I would try leaning out the air screws some, you will have to turn the idle down after adjusting. Get the air screw to the point where it runs clean but does not hesitate when you give it gas, if it stumbles you have went too lean. Make sure you run it at 1500 rpms for 30 seconds after each adjustment to check, all of which should be done on a warm engine.

The first thing I did was bring the idle down by adjusting the idle screw because it was consistantly running high and then turned out the 4 air/fuel screws a 1/4 turn so it would not stall when going into gear. this seemed to work for a little while but now im back to a climbing idle. So i watched the secondaries when bliping the idle and i looks like they are closing all the way but i see fuel dripping in and when i would manually put pressure on the shaft my idle would come back down, which is why i believe the secondaties are sticking a little or something? Just not sure if im correct or if they are, how to i fix?

I have the same problem with a Pro Systems 950. After running hard in real rough water, I have to blip the throttle to get it to come down, sometimes it takes a few blips to get it to drop. Mine seems to stick at the same point as yours, I'll come into the harbor and it will be idling at 1300. I'm going to pull the carb this fall and check the blade alignment and return spring.

My engine was just rebuilt and was tuned on the dyno and ran great but after a few runs in the boat i have this issue. I always used to have to blip the throttle a few times (old motor, same carb) and it would come back down but not it doesnt at all, no matter how may times i blip the throttle. Actually blipping the throttle can make it climb even more.

i have seen many times where the cable needs to be adjusted to push the carb against the idle screw.

fixx
 

sounds like too much cfm and fuel for your engine,,,whats the cid?are you using a crossover with out a thermostat?..

+1.

Make sure when the throttle cable itself is fully closed at the helm, there is no slop at the carb linkage. You want it to kinda force the throttle linkage closed. A few turns of the cable adjuster at the carb would do this.

Also, blast the linkage springs clean with carb clean, then a light coat of grease on the linkage and accelerator pump cam may help.

+2 Good tip, will be checking my cables

thanks for the replies, I'm gonna check my cable, lube the secondary shaft and also put another lap on the secondary spring and see what it does, go from there. Appreciate the advice.