Does that mean you have to crank it a long time before it starts when the engine is warm?

Do you turn it off  and after it sits for a period of time like 10 or 15 minutes, it turns over at normal speed but takes a while to start?  Or is it sluggish turning over.?

Do you have to have the throttle wide open to get it to start when this happens?

Some people have thrown lots of money and about every part they could at the problem with not much luck on their gt40.

Here's a link to a pretty recent thread about longer starts when hot that's maybe not quite finished yet 

http:///www.correctcraftfan.com/forum/forum_posts.asp?TID=48524&PN=1&title=gt40-takes-longer-to-start-when-warm" rel="nofollow - link

The issue arises yes, after turning it off and it sits for a period of time.  10-15 min, or also maybe 2 hours.  

Turns over at normal speed; not sluggish.  Does not need to crank for a long time.  Starts, but runs rough (RPM oscillates low, high, low, high, low) then dies.  It usually takes a few tries of that, and if I shift into gear at the right time (when RPM high) it runs and keeps running.  I do not need to have the throttle wide open to get it to start.  After I get it running then all good.

You say it's not a serious problem but how do you know until you find the trouble? You could be flooding the engine with a leaking injector/injectors and washing those cylinder walls of it's protective oil film causing that cylinder to wear. Dropping it into gear with the rev's up could damage the trans as well. 

http://www.summitracing.com/parts/anm-cp7818?seid=srese1&gclid=Cj0KCQjwvvj5BRDkARIsAGD9vlLoDIfOjAnh3X9U6cVKDuOkQixIh7VkodVfqB5rPYrRbE3_su6BUsEaAu54EALw_wcB" rel="nofollow - http://www.summitracing.com/parts/anm-cp7818?seid=srese1&gclid=Cj0KCQjwvvj5BRDkARIsAGD9vlLoDIfOjAnh3X9U6cVKDuOkQixIh7VkodVfqB5rPYrRbE3_su6BUsEaAu54EALw_wcB

Gary,

Your link didn't work for me. Here's one I found at Summit but it's $50

https://www.summitracing.com/parts/anm-cp7838" rel="nofollow - https://www.summitracing.com/parts/anm-cp7838

Jeff,

As Gary mentioned, it's not a marine fitting. All it is, is a Schrader valve. 

Here's a link to Gordon's loping issues and what worked for him ...................... But not for everyone with the same symptoms

. http://www.correctcraftfan.com/forum/forum_posts.asp?TID=24848&PN=1&title=gt40-engine-loping" rel="nofollow - link

Dang, I was long winded....  ;)  Good thing about that thread is several of us were having similar issues, so a lot of test suggestions came out of it.  So a slew of things to try in that thread.

It seems from some responses that the inlet idle control valve may be suspect.  Even when I don't have the stalling, if often idles high (1300 RPM?) after starting, even when warm.  But for starters, is this the inlet idle control valve:

Can I just remove it (2 bolts + wiring harness) and clean with carb cleaner for a possible easy fix?  

If you remove the idle control valve and start the engine, it will idle I think somewhere in the 1300-1500 range (should be in my previous write-up) because all the air that the ICV was blocking is now flowing.  

Just FYI, I cleaned the snot out of my original one and didn't get any improvement (bad idle).  As I mentioned previously, when it was having the loping issue, to test, when it was loping bad, I shut it down, very quickly removed the ICV and started it again (within a minute or less).  I then used my finger to block the air to drop the idle from the 1300 or so down to 650 or so.  I got no loping when I manually closed off the air with my finger.

So I just bit the bullet and bought one hoping against hope it would solve it (everything pointed to it at that point).  I was estatic since that was it after all of that hassle.....  ;)

Note that when the engine first starts, it will initially idle high (over 1k), but should drop back down to normal idle within 5-7 seconds (haven't timed it, just seems that long).  That is normal.

Hopefully you clean yours and that solves it.  Mine ended up being bad, so cleaning didn't change anything.  But in the end, replacing it was the only way to absolutely confirm it was the problem.  But after all the testing, etc. I did, there really wasn't any other possible fault (and using my finger to control idle speed was a good indication the problem was the ICV.  After all the hassles with it, the time troubleshooting, etc., springing for a possibly not needed ICV was a no-brainer for me.....  ;)

Dang!!  That's clean!!!  I've only had my current GT40 for a year and a half but since I haven't had the loping issue, I haven't taken the IVC off yet.

Yea ever since Gary retired all he does is sit around and polish his parts  

Make sure you put it back in the middle of the boat where it belongs, not "backards" in the rear.

Wow!!!  I thought pulling the ICV out each time would be a bit of a hassle (although really easy), but pulling the engine after each outing like your picture?  Impressive!!!!