04 fe450 (Keihin) stalling when it gets hot

HI V,

Okay let's have some info, where do you ride? stock jetting ? boiling over?

You need to replace the coil wire if it's tracking like that. I don't think it's related to your stalling problem, but it's not a good thing.

Hi there BigV,
The spark plug wire should not be jumping a spark.I would address this issue asap and then see how your bike runs,also the pilot screw should not be a 4 turns out.1.5 is the norm.

I think you have more than one issue to deal with. As Dale stated more info is needed. At first blush I would say the coil wire needs to be replaced of course, the valves adjusted and the pilot jet could be leaned one size and put your fuel screw back to 1.5 turns out from fully seated.

When you remove the float bowl drain plug this gives you access to the pilot and main jet. The previous owner may have done some jetting. When the engine is cold it requires a richer fuel mixture. Once it warms up a leaner mixture is required. This is especially noticeable at small/partial throttle openings. To cure decel popping it is common to increase the pilot jet size, however if the valves are out of adjustment it will also cause decel popping mimicking a lean pilot circuit. The newer (04 & up) e-start bikes will still start with the valves quite out of adjustment. If you had a kick start only bike you would know right away if the valves needed attention as it would be very very difficult to kick start.

bigV said:

It's stock jetting (as far as I know - I cleaned the carb and all the jets, but never noted the sizes). The bike never boils over, just this stalling.

One more thing - when I was cleaning the carb, I noticed the previous owner crushed the drain plug - probably overtightened it, crushing the gap for the washer. I didn't have another at the time, so I sealed it with high-temp silicon.

Click to expand...

Do not use silicone seal as a gasket to seal any part of the carb, as it is readily dissolved by gasoline to form a very gummy substance.

The stock jetting is may be on the lean side.

Hi BigV

if you get a whack then something is wrong so get it sorted. full stop (period to yanks). as for jetting i think that you're lean (as per chas), the reason being that you turned the PS out 4 turns. as NSman says: 1.5 is about right. b;ocked jet|?

you'll find that when you do the electrics, the rest will go back to normal.

but THEE classic staller when warm is TAPPETS! (husabutt)

another one MAY be fuel vapourization. try and lean the carb to 11 'o clck for a ride.

regards

Taffy

When you check the jets be sure to check them all. That includes the Main Air Jet (MAJ), Pilot air Jet (PAJ), pilot jet (PJ), Main Jet (MJ), and the start jet (SJ). You also need to check which needle is in the bike and what clip position it is on, and that is measured by how many notches from the top the circlip is on. Remember, from the top! The main reason I'm asking for this info is that it is a used bike and you need to make sure what you have in there from the beginning. Oh yeah, see my gallery for the stock setting of the accelerator pump/

You might also verify that your floats are set correctly while you're in there.

Once you have provided us with all that info there are several of us here that will be glad to give you some advide as to how to proceed.

However, I will offer this observation in advance of your information based on what you have said so far. It sounds to me like you are getting a rich stumble off idle when the bike is warmed up. This symptom has plagued a few of us with the FCR carb, but, fear not it is cureable with a bit of work. If I had to guess I'd say that you are rich on the pilot circuit, that combined with the squirt from the pump is what's giving you that stumble. I have only had really bad problems, such as you describe at high altitudes. Above 10,000' density altitude.

The popping on decel can also be associated with having too lean of a needle setting, aka clip posiiton. It is not unheard of for someone to over compensate this lean needle condition with too large of a pilot jet, which would lead to your rich stumble off idle.

Get the info, real numbers please, and I'm sure we'll help you get things sorted before you know it.

another thing bigv

could be your plug is old and tired. suggest you try a 'posh' plug this time. try the iridium NGK's or like me, go for a nippondenso IXU24. do a search on the net.

regards

taffy

I know that everyone seems to have a different fix for this problem, and here is mine. I have an 06 FE450, and it had the same problem. After it was jetted quite close to perfect (note, it still had the hot off idle stumble), I rerouted the fuel line, removed the thermostat, and decreased the throw on the accelerator pump rod a bit. I have not had the problem since. I do notice a bit of lean reaction right off idle until warmed up, a couple of minutes. Not a problem. With winter coming on, I will reinstall the thermostat. This stumble is definitely a heat related problem, and only plagued me in rough slow going. I also would notice an improvement after a ten minute rest. As it is, this is the best running bike I have had in my life, and I'm an old fart! I still say that the correct solution is for Keihin to make an FCR carb with a right hand side fuel feed. Otherwise, a clever reroute of the exaust would help. Good luck!

The carb fuel lines do run close to the exhaust and a different set up is in the works I think.It seems to me that the carb position and frame design is really still from the days of the Dellorto carb.The FCR is a late edition to this 01 frame/exhaust set up and will not really be cured untill the next generation Berg...

buzzard

there is a very easy cure for your stumble and that is to lift the needle and lower the main jet to around 160. i bet you have far larger in it, right?

i run a 145 BTW.

regards

Taffy

nsman said:

The carb fuel lines do run close to the exhaust and a different set up is in the works I think.It seems to me that the carb position and frame design is really still from the days of the Dellorto carb.The FCR is a late edition to this 01 frame/exhaust set up and will not really be cured untill the next generation Berg...

Click to expand...

Wouldn' a little heat wrap around the pipes in this area be an easy remedy?

husabutt said:

nsman said:

The carb fuel lines do run close to the exhaust and a different set up is in the works I think.It seems to me that the carb position and frame design is really still from the days of the Dellorto carb.The FCR is a late edition to this 01 frame/exhaust set up and will not really be cured untill the next generation Berg...

Click to expand...

Wouldn' a little heat wrap around the pipes in this area be an easy remedy?

Click to expand...

If you are having this problem,there is no reason why wrapping the pipe will not work.

I have pondered wrapping the pipe, and have not done so for two reasons. One, the wrap would rub on the carb. Two, there is precious little space for air flow around the carb as it is, any other material in that area would decrease it. I have left my 450 as it is, and have not experimented further, because it runs superbly. I run at an elevation of 6000-9000', and am running a 178 main, 42 pilot, and am forced to admit I have never looked at my needle. I can go to places like Moab at 4000', or over the high passes at 10,000', and not rejet. Now I know I should, and would, if I was going to ride these areas for any extended time. My plug is a nice medium brown, my bike starts easily, and runs throughout the operating range very strongly. I will say that fuel milage is a bit less than my old 2000 FE501, which I attribute to the accelerator pump. I agree that the misfit of the carb is due to the frame being designed around the Dellorto. By the way, my 2000 FE501 had a similar heat related stumble, and I found that the Dellorto got pretty hot on slow going tight trails, the pipe was really close to the carb on that bike too. I have wanted to try "race gas", to see if it was less prone to vaporization, which is the culprit as I see it. The altitudes I run at are a contributing factor, as liquids vaporize at lower temps at higher altitude.

buzzard

what can i say? if i ran mine at altitude i would be on a 135 main. i left TT because you simply can't fight everyone who has been misinformed. i just want you to know that a 160 would be plenty for yours without moving the needle. the 35 or a 38PJ would be great. leave the needle wherever it is.

don't worry about the fuel, that's a phalasy. you shouldn't even be getting a plug colour with the kokusan ignition. your bike is very, very rich. so rich that to get it down will send you through coughs and splutters, different methods for startring the bike. it's simply too much to ask you to start that journey and for you not to doubt me. even the first jetting drop would see you misreading all the symptoms.

so i'll just leave you with the info. it's there for you ok?

this to me is the equivelant of someone running their fingers down a blackboard and there is nothing i can do about it.

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