High Idle

I finally have my boat to where it runs again after a long summer of working on it as usual. However, my idle speed will not go below 900 rpm or so. I've rebuilt the carb, made the adjustments, and have the timing set at about 12 btdc at 900 rpm. I figure that should be close at the spec is 10 btdc at 700 rpm. I hooked up a vacuum guage and I am getting 18 in Hg steady at this rpm. If I go any lower, then it surges and dies. I checked for vacuum leaks around the carb base and found none. It was running rich, but I found that the accelorator pump was slightly actuated at idle, so I adjusted that. I do have a mild cam in the boat, but 900 rpm still seems a bit high. And yes, people shake their fists in the no wake zone. I've had this boat for over a year and have never seen it idle below 900 rpm. Any ideas? Maybe the tach isn't accurate. The idle sounds fine, but the guage shows high. I am at a loss with this issue.

My boat is the same (cam w/incresed compression and no idea where the timing should be set)....after getting her running, we experimented with the timing (while running in the lake with and without a load) till it started smoothly and accelerated without knocking. Sorry, can't remember which way we went!

Let us know what happens and good luck.

Does it have a PCV valve? Defective?

I was having high idle probs too...after going through a bunch of ajustments(carb,timing and ignition) I found a vacume leak...problem solved! I found the leak by blowing cigarett smoke arround the carb spacer...it sucked it right in at one spot.I now idle at 600 rpms and it is as smooth as a babies behind!

When mine was fast... I was told by the lake patrol to slow down...so I know what you mean!

If your idle is too fast...it will take a toll on the tranny...it should be smooth going into gear ...it would be best to find a fix!

It's actually smooth when it goes into gear. Maybe my tach isn't accurate. Oh well. It will be a mystery that I can live with.

Running at 900 is about what mine likes to idle at. With the cam it needs a little more rpm at idle. A couple of suggestions for the no-wake zones, go a lot slower by going in and out of gear and I have also changed my prop to bring down the rpm's on top end bbut it also help the idle speed by having a slightly heavier load on the drive-line due to the increased pitch dropping the rpm down more.