2003 F40TLRB Rough Idle

Great site...

I just bought a 13ft whaler with this on it and had to clean out all 3 carbs which were gummed up from sitting for 2 years with stale gas. It idles rough and there doesn't seem to be any idle mixture adjustment on this so I'm assuming that the idle jets control it ?? I had to thoroughly clean those out as well but since the openings are so small, I'm wondering if I will just have to replace all 3 with new ones.

Thanks

MikeL

[boats.net]

We soak them in carb cleaner and use compressed air to clean.

[captflossman]

Did you re-sync the carbs with a vacuum gauge?

Carb Synch

I didn't mess with any of the adjustments assuming they were probably correct to start with. The tach only shows 20 hours or runtime.

[captflossman]

If you pulled the carbs off of the motor then chances are that you are way out of sync. The mixtures are probaly off a little and that will make that motor spit and shake very bad in idle. I have a 03 f60 and I did the same with a carb rebuild figuring that if i didn't touch the adjustment screws that it would be alright. It ran like crap after and i had to hook it up to a vacuum gauge. You should be able to rest a quarter on top of the cowling when in idle and it should stay there.

I didn't mess with any of the adjustments assuming they were probably correct to start with. The tach only shows 20 hours or runtime.

Thanks Capt. I finally received all of the paperwork and it turns out the carbs were rebuilt for the same reason several years ago by a shop. I'm going to order 3 new pilot jets and see what happens. If that doesn't resolve it, I'll pursue the synchronization. I'll have to locate a vaccuum gauge setup first.

[captflossman]

Here is the one to get.

http://www.casporttouring.com/store/...OD/MorganT/243

This synchro works awesome and is very fast and accurate. Just plugs in to all cylinders while running and adjust idle from master carb at bottom of motor. Then just slowly adjust all other carbs to measure the same. Best one on the market.

f40 idle problems

the backordered pilot jets finally arrived and I swapped them out. Made a noticeable difference but it still doesn't idle like my 9.9 4 stroke. Will have to purchase a vaccuum gauge setup. The one referenced above looks great for $100. Saw a reference to yamaha yu-44456 vaccuum mate synch gauge in one of the posts by boats.net. How much are these? I'm probably only going to use it once or twice but if I have to spend $100 for something that works correctly, so be it

f40 idle problems

the backordered pilot jets finally arrived and I swapped them out. Made a noticeable difference but it still doesn't idle like my 9.9 4 stroke. Will have to purchase a vaccuum gauge setup. The one referenced above looks great for $100. Saw a reference to yamaha yu-44456 vaccuum mate synch gauge in one of the posts by boats.net. How much are these? I'm probably only going to use it once or twice but if I have to spend $100 for something that works correctly, so be it..

Thanks

MikeL

[captflossman]

I assure you there is not a more user friendly and accurate vacuum gauge on the market than the afore mentioned. It has four separate meters so you can measure vacuum pressure and make adjustments while running. Just set up bottom carb until you get to desired rpm at idle and then just sync the others to match. Very easy and no mercury.