04 fe450 (Keihin) stalling when it gets hot

Taffy, I do not doubt the truth of your information. I will try going leaner on the main, in increments, and will let you know the results. I will say that I am still runing the spark plug that came from the dealer new, and it is not at all fouled or caked with debris. Also, the excellent folks at Motorcycle Specialties in Sparks, Nev, from whom I purchased the bike, had jetted it using the experience they have (alot), and were within one pilot jet of perfection(according to me). So, if it is that rich, wow, I cannot wait to see how it runs when correct. Thanks, I'll let you know. And I don't even have a blackboard!

For what it's worth....... And I don't mean to hi jack your thread here.

I found this set up for my 04 550 for high altitude riding. And by that I mean 7700' to 9000 or 9500' msl. That is 10875' to 13056' density altitude (80 degrees F, 29.92 Hg , 45 degree dew point).

DVT needle @ #4
175 main
45 pilot
1 & 3/4 turns out on the fuel mixture screw.
accelerator pump gap @ .115 (or 1/2 turn retarded)

This cured all my problems at high altitude with the rich stumble. I'm sure that I could probably go leaner on the main by a few steps but did not have the time to putter with it. The fuel mileage with this set up was excellent while averaging about 15 or 16 mph I got about 35mpg on a 37 mile loop. This was all pretty tight single track stuff.

eeewww baby!!!!! ggggrrrr! austin here. feel that resistance b-a-b-y!

i'm not saying anymore. i mustn't, i mustn't.

(bits fingers)

regards

Taffy

Last night I even dreamed about bloody jet sizes :lol: Can't wait to get my hands on it and try some of the suggestions.

Cheers
V.

bigV said:

Last night I even dreamed about bloody jet sizes :lol: Can't wait to get my hands on it and try some of the suggestions.

Cheers
V.

Click to expand...

Hope you didn't wake up with a stiffy.

Goodluck with the jetting. 8)

No, they don't excite me that much :lol: It was more of a nightmare!

Ok, gents. Just having a coffee break while working on the bike, so I thought I'd post the jet sizes etc.

First of all, I'd adjusted the valve clearances. A bit of a nightmare (first time I done it), broke one of the gaskets as the cover was stuck solid. Of course I don't have a spare one - so I cut one out of gasket paper and used high-temp silicon from both sides. Hope that's OK.

Valves were quite a bit out, I'd say (loose) - I tried using a feeler gauge, but gave up, it just wasn't worth the effort. I used the 1/6 turn technique. Hopefully it'll be OK. I tried it, the piston turns OK, rockers seem to rock OK , hopefully my valves will not meet mr. piston anytime soon.

Then I tackled the carb again. The high-temp silicon I used on the broken drain plug looked OK - didn't turn into the jelly stuff I expected. I have a new plug - but no bloody washer - does anyone know what it should be? I presume it should be a crush washer, slightly raised above the flat bit in order to make contact with the carb body...

The jets are: main 178 (stock), starting 85 (stock), idling 40 (stock should 38 ), needle position - clip on the lowest (7th from top) - stock is on 6th.

So, where does this leave me? Should I move the clip on the needle to the stock? I do not have any other jets handy, so I'd prefer to keep it as is, if possible.
Do I need to worry about the air jets?

Thanks
V.

but what is the code on the side of the needle? you should read OB then three letters?

IMHO you need to look up the doc and suss a few settings there!

sorry if you need to sort this but it's very important....

regards

taffy

Hi Taffy,
Damn, I never wrote it down. I think it had OB and V-something. Since I was eager to get it running again, I moved the clip to the default position (6th from the top) and cleaned and re-assembled everything, setting the mixture to the ideal 1.5 turns. I took it for a spin - the noise I attributed to the chain seems gone (I think that was the valve clearances - it that possible???). It was quite late, dark and cold, and I couldn't take it properly off road to get it really hot, but it seems better. It still stalled a couple of times, but in a different way (not like it's flooded off the throttle). I may need to adjust the mixture a bit. But considering it's on the default 1.5 turns (unlike 4 turns as before), I think that's a move in the right direction. I will not be able to conclude until I can take it properly into mud, which will be next weekend.
Changing the needle position also affected the bike's throttle response - but I can't decide if it's better or not - it seems a little more hesitant initially (still pulling strong enough, though), and a little better up the rev range. As I do leisure riding only, I don't really worry about that. One more point - as I was removing the carb, I noticed the rubber boot that connects it to the frame had quite a lot of oil in it - how does it get there - I didn't overfill the bike when I last changed the oil...Perhaps when I fell? Is that something to be concerned about?
Cheers
V.

until we have the needle code we don't know anything.

the oil is in the 'sock' from one of your falls.

regards

Taffy

Hi guys,

The needle is OBDVT. Now back to default (6th from top) clip position. I've not been able to "warm it up" properly (can't until next weekend), but it seems to run better, after changing the needle position and adjusting the valves.

Cheers
V.

bigV

i get the feeling you're not upo for this but here goes.

ok my recods show that april 2005 was the last time i ran my 400 similar to your bike and this is what i had.

it's a 400, it had th 501 headers (same as yours) mx tailpipe (yours is freer flowing later model FE so evens it up) lineaweaver LX2 cam (same as yours). 39mm mk1 keihin to your mk2 so same essentially.

150MJ
DMS needle on clip 2
35PJ
45PA (you don't have this so don't worry)
1.25 turns PS
75 starter

i now have a lineaweaver needle in and the needle straight falls between an S and a T and as you can see i ran a dmSSSSSSSS and you have a dvTTTTTTTT so you're ok there.

would you believe that your needle on clip 6 and mine on 2 were identical so now we have the same needle angle, the same needle taper start, the same thickness of 'straight bit' of the needle.

your PJ is a 40 to my 35. BUT THE MAIN DIFFERENCE IS THE MAIN JET. I HAD A 150 AND YOU HAVE A BUCKET WITH HOLE AT BOTH ENDS CALLED A 178.

even dale started out by recommending a 150 but bigburger got all frit up over something or other so dale played safe at 160 i believe. so there you have the answer as to why you have to rev it to get clean running.

get yourself a 160 and could even go lower IMHO if you were cautious. the problem for huseys is similar to that for the WR400s we used to set up on TT. if they were slightly rich you got an off-idle-bog but if they were VERY RICH they were ok again!!!!!!!!

so there i was with JD begging people to try 158s and they were getting bogging with 172s. for one of my posts there would be four that said 178/180 had cured the bog.

some nights i used to cry myself to sleep. :cry: :cry: :cry:

regards

Taffy

Taffy,

I much appreciate the time you're spending on this (and all the other guys). I'm phoning today and ordering a 160 main jet. Worst case I can always go back (getting good at removing the carb from that tight frame!).

Thanks very much, I'll let you know how I get on (hopefully they will have one and send it for the weekend coming).

V

big V

i don't know how you are for cash but sudco probably have a minimum order and you should really have got yourself a 155 and a 165 whilst you're there. if i was an american and i was happy with my jetting i would send you a few to try FOC and then buy the one you need.

IMO your bike won't run lean however it will be prudent if tyou test the new main jet with a bloody good thrashing in a straight line. a lean bike sounds thirsty - it's the only way i can say it! it just sounds dry from the exhaust.

ok that's the caution over and expect the bike to be ok. MJ testing is in 5th and especially 6th if you were to thrash the bike through the gears ok?

if you find it's like you've been given a turbo in the top three gears - i was right!

forget the low speed stuff at this point. glitches coughs and all that bollocks IGNORE them. this is MJ time.

if you have that right you should then set the PS so that you can pull wheelies in second in tickover. no hesitation just no to go. that simple. 0.5 turn either way will be enough i should think.

you should have disconnected your APJ anyway or reduced it to virtually nothing. that is a given i trust.

finally you need to try the needle up or down a clip. i suggest you ride with no rad flaps for all this - quick changes.

no tricks to the needle. i used to get it wrong all the time. that's why you should try up and down. the needle is for mid range so now you should have the MJ done and the needle.

you will now have to set the PS again probably.

one day we might even wheen you onto the 35PJ. very few use this jet. let's just call them disiples....

:wink: :wink:

regards

Taffy

Thanks Taffy,

I've asked Andy at ATC Motocross to get me one other jets as well (165; I'm kind of stuck for cash now, having to get new throttle cable, break pads etc.). I'll start with 160. I'm not sure I'll be able to tell if it's lean, hopefully I'll give me no problems. Looking for a turbo effect, that should be easy enough . With my gearing (14/52) I should not take off.

Pulling wheelies - last time I tried that I ended up in a hospital . Well, at least I realise I'm not the most gifted rider . I'll settle for no hesitation off the throttle.

What's with the APJ - tried to look for it here - something with the accelerator pump? How do you reduce/disconnect it? Excuse my ignorance...

See how it goes, I just hope to get all the bits before the weekend...

Cheers
V.

bigV said:

Hi guys,

The needle is OBDVT. Now back to default (6th from top) clip position. I've not been able to "warm it up" properly (can't until next weekend), but it seems to run better, after changing the needle position and adjusting the valves.

Cheers
V.

Click to expand...

Here's another perspective: the stock DVT needle has such a large diameter towards the tip that it blocks the main jet, no matter which one you choose to run. I never even started my bike with that needle. If you choose to run the leaner main jets that Taffy suggests, I would go with an "E" series needle, OCEMN would be a good starting point. The "E" series needles have less taper and are thinner, allowing them to work really well with leaner main jets. Combine that with Taffy's main jet suggestions (160), and your bike will rip.

As far as limiting the squirt time, the easiest way is to fit the AP diaphram from a Honda. I don't have the PN, but it is what I am running in my Husaberg. Limits the squirt to less than a second, and will work perfect with my recommended jetting.

EMN needle readily available from Sudco, they probably have the AP diaphram too.

Thanks John,

I've asked my supplier to price that needle as well, I guess it won't be to expensive, and I can give it a try.

Cheers
V.

having tested the two nnedles extensively and back-to-back i ought to warn you that there is a balance to be struck. the D series is a superior needle up to 1/4 throttle. that's woodlands, short squirty stuff, hops and wheelies etc. the E series needle is superior fron 3/4 throttle, from 5th gear onwards.

put it this way, i race and i swopped between the two okand finished with the 'D' series. can't agree with EMN that's the needle we ran in the yams and was where i started with in the huseys. the NNNNNNNNNN is too rich and needs to be around a Q. i ran EKQ. this is a yamaha needle and is anodised and tough unlike the keihin stuff which is brass.

anodised is OB and brass is OC coding.

so why the Q and not an S or a T i hear you say. the reason is (and john doesn't tell you this) there is a pivot point about a third of the way down the tapered part. if you bring the point in the tapered sides hit the parallel sides earlier. now stick the needle in the atomiser and it's on the straight part for a further 3-4mm. this means that you open the throttle and more air pores in but the needle hasn't started to 'thin' thus we have hesitation. (let's put it another way bigV, ever make a paper aeroplane at school? looked like concord right? well imagine the tapered sides going out earlier to look like a hang glider..... get it now? those long straight sides are the needle at idle and they should taper in AS YOU TOUCH THE THROTTLE!) so we compensate with large PJs and that means we run real soggy at 1/4 to 1/3 throttle - right where you want it.

there is nothing to chose between EM and EK but there is between the N and the Q.

john is right about the MJ difference. but i didn't tell you bigV that i run 148MJ with an 'E' series tip. so 160 is right for a D and 152 is right for an E. even JD accepted that 8 was the correct difference. dale recommended, as said a 150 for his E tip.

regards

Taffy

I know Taffy has done extensive testing on jetting, especially needles. We have many variables between our two bikes, mine being an FCR 41 instead on the 39 that I THINK Taffy is probably running on his 400, as well as my bike being a 550. The bigger bore bikes, especially with the bigger bore carb, DO run richer main jets, even with the "E" series needle.

I too have tested lots of needle combos, even the brand "X" aftermarket ones Taffy doesn't like. For my bike, and my application, the thinner "E" series is superior to the "D" series of needle, at any throttle position.

Flame away Taff.

no, i shan't flame away...it's a thin line twixt the two but they are seperable. i jusat want to win this debate that's all (LOL!!).

i've gone to 41mm about 5 months ago and it didn't chnage the MJ as i knew it wouldn't. also the 550 would need at the most about 5 less than mine on MJ.

i'd prefer bigV to go through the correct process and if he just takes a simple precaution he'll be ok. we had one scare here and i don't think it was dealt with too well. the rider panicked, admitted to not testing it (said that it was great in the yard, then it was probably crap in the yard) but given that i ran 150MJ on a near identical bike thewn i'm certain he'll enjoy the difference. 160 is real easy on it.

question will be, will he panic? will he try and work it out by doing the hard yards?

my records are littered with
150MJ C3
150MJ C4
150MJ C2

you get there in the end and it's very satisfying to get it right following your hunches.

i would never call my ol mucker JD wrong. it's just that lineaweaver and i have his number and dale has tried his products..... i'm telling you john, it's a good man who can hold a candle to me on jetting.

i still get INVALUABLE help from PMK on K-Talk. i joined the orange side and posted once. PMK said how chuffed he was to have me along as he had always used my jetting. now, anything i'd like to ask, he'll always help as he is a great sussie geek. or guru as we might call him.

that's greatly appreciated and makes it all worthwhile....

regards

Taffy