2009 yamaha F40 TLR question

[ragbul10]

I am currently cleaning and rebuilding my carbs and have a question one of you guys might be able to help me out with. I screwed out the cap covers of the pilot screws and removed those to help me get a good cleaning (now my third attempt on these carbs, Yamaha screwed the pooch on these) and I am wondering how far back off lightly seated they should be when I put them back in. The book says there non adjustable but through this forum I tapped the covers and removed them to try and clean them the best I can. I am ultrasonic cleaning them now and when I go to reassemble I need to know ball park how many turns to back them off. I know other yamahas I have are 1 1/4 to 1 1/2 but want to make sure.
Like always thanks guys.
Danny

[boscoe99]

Need the complete model identity of the motor.

Here in the USA there is no F40 carbureted model that was offered as a 2009 model year motor. The fuel injected F40A was offered in 2008. The last F40 offered here in the states was the F40BTLR/F40BMLH/F40BEJR. An F40TLR was last offered in 2006.

Maybe you bought your motor in 2009.

More than likely the idle mixture screws for you model should be set for two turns out from being lightly seated. Then plus or minus half a turn if needed for a better idle quality.

The idle jets in the F40B/F40TLR models are #38's. You can clean those carburetors until hell freezes over and still the motor more than likely won't run worth a crap. You can install the original jets, sized #40. The motor more than likely will still be a problem.

If you install #45 jets the motor will start, purr and run wonderfully well. Also, it is essential to use a vacuumate type device to synchronize the carburetors.

Oh, when you advance the throttle quickly do you see fuel spray out of the accelerator pump nozzle? That nozzle can be a bitch to get cleaned.

[ragbul10]

reply

Ok ya I have a vaccum synchronizer and have used it in the past and Im sorry on the F40, it is a 2009 carb model 40 horse. Is there another motor that uses the #45 jets to order them or do they make them for this motor. I have not noticed fuel spraying out either. I have attempted this now for the third time so maybe the new jets will be the way to go. I know these carbs are garbage but whatever I can do to get this thing up and running Im ****. I have them in an ultrasonic cleaner now and using compressed air but we will see if this time is any different. Ill keep you posted on what happens.
Danny

[boscoe99]

I still don't know what model motor you have.

Is it or is it not a four stroke model?

What country are you in?

We here in the US did not have a 2009 F40 carbureted model or 40 two stroke Yamaha available to us.

It might be useful to hear what are the problems that you are having. Hard to start, won't idle, won't accelerate, won't reach top end RPM, stalls when power is reduced or ???

[ragbul10]

sorry I got busy with other stuff but my model is a F40TLR 67CL1032102. Here is a run down of the problem. The boat ran great until one day running WOT it started bogging down and running like crap. Through this and other forums figured it was a carb problem because these motors carbs are garbage. I have cleaned the carb three times now in an ultrasonic cleaner and compressed air and it will idle fine all day long and starts right up. As soon as you put it in gear it vibrates bad and runs like garbage through all RPMs and will bog down and die if you put the throttle up half way. I don't know what else to try with this thing I know it is getting spark and it has fuel and everything else basic is fine so I am assuming the carb is still the problem. I don't know what else to do but am interested in changing out the jets to the larger size. Not real sure bout the sizes and such but do you know how I would go about getting the larger jets. Does another motor use the larger jets so I could order them or do you have a part number for them or what do you think I should do? This thing is driving me nuts.
Thanks
Danny

[boscoe99]

PM's sent to you.

[jpbrennan34983]

Danny, did you figure out what the problem is yet? , I have the 50TLRC and it is doing the same thing

[boscoe99]

Danny is MIA.

A 50 two stroke is a piece of cake compared to the dreaded carbureted F40 model.

[jpbrennan34983]

Boscoe99, would you have any idea why my 50tlrc would be bogging on acceleration, it doesn't do it all the time only at the worst time, like coming in a choppy inlet, I have changed all filters, fuel line and primer bulb. I wouldn't think it is the fuel pump if sometimes it is okay and sometimes not?

[ragbul10]

sorry no Im just busy with work but I got your PM and I am going to check into what you said Im not sure if I have the Y.E.S. or not I am going to call but no I have not figured it out. Bosc if I have to go the larger jet route what engines jet would you recommend that would be larger and hopefully solve this problem.
Thanks and sorry bout the delay.

[boscoe99]

Boscoe99, would you have any idea why my 50tlrc would be bogging on acceleration, it doesn't do it all the time only at the worst time, like coming in a choppy inlet, I have changed all filters, fuel line and primer bulb. I wouldn't think it is the fuel pump if sometimes it is okay and sometimes not?

My first guess would be something amiss within the carburetors.

Your motor is about ten years old now. When was the last time they were cleaned?

[TownsendsFJR1300]

+1 on the carb cleaning on BOTH posts/motors.

If the engine ran fine for 10 years, it doesn't need re-jetting now. There's crap in the float bowls or jets.

You can start by draining the float bowls and catch what comes out with a small container. Look for any debris, water droplets or cloudy fuel..

With the the ethonol in the fuel now adays, you need to run FUEL STABILIZER 100% of the time to keep the fuel from varnishing up the inside of the carbs.. "Gas Shok" works very well. Usually, its the main and idle jets that clog up.

You MUST pull and be able to visably be able to look thru the jets. Spraying carb cleaner alone into the jet while installed, may not work, then you get to do a "do over".

I'd also strongly suggest running Yamaha's "Ringfree". Its NOT a stabilizer but a fuel system and top end cleaner that works extremly well and very concentrated, (1 oz / 10 gallons).




Its actually recommended in the owners manual of my Yamaha manual..

[ragbul10]

townsend my motor is only about 5 with maybe 25-30 hours on it. I have pulled them off and cleaned them in an ultrasonic cleaner three times and blew compressed air and everything else and cant get it to run right. I know these carbs on the 40's were garbage from Yamaha. Folks on this thread and other forums say the same thing about putting the larger jets in to get it to run better. Mine runs fine at idle but when you start going up from there it bogs down and either dies or runs like hell. Im just looking for something else to do cause I am sure enough not buying new carbs for it. Not sure bout the other guy though.
thanks
Danny

[boscoe99]

Maybe Yamaha will buy you a new set of carburetors. Seek and maybe yee shall receive.

[TownsendsFJR1300]

townsend my motor is only about 5 with maybe 25-30 hours on it. I have pulled them off and cleaned them in an ultrasonic cleaner three times and blew compressed air and everything else and cant get it to run right. I know these carbs on the 40's were garbage from Yamaha. Folks on this thread and other forums say the same thing about putting the larger jets in to get it to run better. Mine runs fine at idle but when you start going up from there it bogs down and either dies or runs like hell. Im just looking for something else to do cause I am sure enough not buying new carbs for it. Not sure bout the other guy though.
thanks
Danny

Not to beat a dead horse, but did you pull both the main and idle jets out of the carb body? They must come out and unless you can see light thru them, it don't count.

(I'm assumming you pulled the float bowl before the ultra sonic cleaning)..

Another poster (forgot what sized engine he had) posted the same, cleaned it in an ultrasonic cleaner 3 times still wouldn't run right. I pressed him on wether he pulled the jets out of the body. Eventually, I found out, NO he didn't. Some of the jets have holes (very small) than run vertically or sideways thru the jet, NOT just straight thru. Those holes were clogged on his. After getting those verticle jets clean, ran like a top..

Have you used any fuel stabilizer in the fuel in the past? Please answer this, it is important..

Even with LOW hours on an engine, the ethonol fuel will go bad in as quickly as a month without stabilizer. IT will varnish up the insides and clog jets.

As noted above, IF the engine ran fine for 10 years, it won't need re-jetting. If the spark plugs are showing a lean running condition, NOT TAN, definitly replace the jets with some larger, richer ones..


I've never used an ultra sonic cleaner, never needed to... As long as I could get the jets out.

Ultra small carbs (weedaters, 25cc 2 stroke engines, etc), the Ultra sonic cleaner would come in handy as some orifices are so small, I use a hand held wire brush individual WIRE cut off the handle to clean those orifices(the stubborn ones at least)