82 450E Jetting Help Needed - Don't match what's available?

[JohnESuspekt]

on mine, im running pods and factory exhaust with the VM22/210 main jets. ive went through 130,135, and im now at 137.5 but i still feel its running a bit lean as it is a bit sluggish on the throttle and its still hanging a bit. my buddy just got a pack of 140s for his and im gonna try that and we'll see. bike bandit sells them in 4 packs of 1 size for about 10 bucks

 

[Guest]

on mine, im running pods and factory exhaust with the VM22/210 main jets. ive went through 130,135, and im now at 137.5 but i still feel its running a bit lean as it is a bit sluggish on the throttle and its still hanging a bit. my buddy just got a pack of 140s for his and im gonna try that and we'll see. bike bandit sells them in 4 packs of 1 size for about 10 bucks

Hmmm... I think that number is wrong, VM22/210 are definitely pilots, not mains, what size pilots did you end up with? The mains should be the N102/221...

I'm thinking once I get it on the road and get an idea of how it's running, I will find a cheaper place to get jets (probably from the US) and just buy half a doze different sizes or something so I can swap them out without having to wait and buy more locally. At $8.50 a pop here that will add up real quick...

I got the jets today, but unfortunately circumstances dictated that I got about 30 seconds to look at them, although I put some fuel in the temporary tank before that to see if it would leak and left it in for about 20 minutes leak free which is great.

The VM22/210's certainly look externally like they'll be a direct replacement and it looks at a quick glance like the centre hold is the same diameter as the 17.5's, but it has the extra holes down the side. Bit hard to compare accurately in 30 seconds so I'll just have to wait and see whenever I get more time.

On a similar note I think Saturday may be a no go again too, not really surprised about that as it seems to be the way it goes these days.

 

[JohnESuspekt]

sorry you're right, heres the main
http://www.bikebandit.com/mikuni-small-round-main-jet-kn102-221-4-pack?mg=3597&t=1

 

[Guest]

sorry you're right, heres the main
http://www.bikebandit.com/mikuni-small-round-main-jet-kn102-221-4-pack?mg=3597&t=1

Cool, I'm no more insane than when I started then

Will keep Bike Bandit in mind when I get to the real jetting part as that's a good price even if I only need 2 of the 4.

 

[Guest]

Ok, so first off seems there was a miscommunication last night and it looks like tomorrow's bike work is on!

And therefore to catch up, the temporary fuel tank hung up for the test last night which passed:



And the jets:



I tried every which way to get a good comparison pic of the old vs. new but the camera I'm using just won't focus properly up close enough and I'm nowhere near skilled enough to put it in manual mode and manually focus it and all that stuff. Photography is not in my skillset I'm afraid...

However, I at least now know that they definitely fit, and I can see a very small difference in the hole diameter, and it also has those holes in the side as well.

For the start tomorrow though, I'm going to try again first off with the stock pilot jets.

The reason for this is that I've now made two changes since last time, one to change the fuel outlet for the tank, and the second to adjust the float height. I will set the mixture screws back to 2 turns out as well and that will be my starting point. I don't want to change too much as I want to know which change actually made it run.

I've put the larger mains in though as the mains will definitely need to be increased.

My parts from Boulevard didn't arrive this week, so no new intake boots for tomorrow either, although I'm pretty sure they're not introducing any air leaks.

 

[Guest]

:dancing:







So it works! Either John's tip on the temporary tank setup did it or the float height did it, I suspect the tank...

Either way, it runs with the stock pilots in there.

I'm kicking myself because I left the mixture screws at one turn out like they were and didn't adjust them at all, and I also realised today that I haven't degreased and lubed the advance assembly, and I think it stuck a bit a couple of times.

Anyway, you'll see in the video I have a hanging idle and adjusting the idle screw brought it down, which I'm thinking is due to the lean running, but I also suspect some leaking of the intake boots around the carb mouths, so the new boots should take care of that.

Anyway, that's where she sits for the moment, and I've been able to drop the oil and filter and check the stator and R/R as well, so for now that will do nicely

 

[Big Rich]

That's some great news Pete! Congrats!!!

You're gonna be going into overdrive on this now......

 

[Guest]

That's some great news Pete! Congrats!!!

You're gonna be going into overdrive on this now......

Cheers Rich!

I really hope I can, itching to get stuff done now.

$$$ and time are going to be the hard bits of course...

 

[KEITH KRAUSE]

Those Clymer's books are junk. Trust only the factory manual. In todays world there's always a way to get the factory info.
The difference in float level from factory to Clymer's is over 4mm! The Clymer's being much richer. I do have to admit that the factory amount you said (over 26mm) seems very high.
I think the pilots you have now are the correct design. There should be tiny holes along the sides.
The stock pilot jets may work well if you assist them with richer mixture screw adjustments. If up to 4 turns doesn't help then you know the larger 17.5 will be needed as after approx' 4 turns the screws are out of the effective range, maybe a little sooner. Whatever you do, be sure the mixture screws are set using the highest rpm method. You should be able to hear the rpm's. When the pilot circuit is mixing well the rpm's will max out. Of course that assumes the throttle assembly and cables are working smoothly and the cable is properly routed and slacked. It also assumes you are adjusting for highest rpm with the correct base idle rpm.
You also just brought up possible intake leaks which must be fixed first or checked. No point adjusting screws or anything until basic maint'/ prep' tuning is done first.
You're getting there.

 

[Guest]

Those Clymer's books are junk. Trust only the factory manual. In todays world there's always a way to get the factory info.
The difference in float level from factory to Clymer's is over 4mm! The Clymer's being much richer. I do have to admit that the factory amount you said (over 26mm) seems very high.
I think the pilots you have now are the correct design. There should be tiny holes along the sides.
The stock pilot jets may work well if you assist them with richer mixture screw adjustments. If up to 4 turns doesn't help then you know the larger 17.5 will be needed as after approx' 4 turns the screws are out of the effective range, maybe a little sooner. Whatever you do, be sure the mixture screws are set using the highest rpm method. You should be able to hear the rpm's. When the pilot circuit is mixing well the rpm's will max out. Of course that assumes the throttle assembly and cables are working smoothly and the cable is properly routed and slacked. It also assumes you are adjusting for highest rpm with the correct base idle rpm.
You also just brought up possible intake leaks which must be fixed first or checked. No point adjusting screws or anything until basic maint'/ prep' tuning is done first.
You're getting there.

Cheers Keith, yes to all of the above!

My parcel containing the intake boots cleared Australian customs on the 9th so they should be here today/tomorrow I would imagine, and that will solve my potential intake leak.

The reason I thought I had one was when I shut it off I heard some strange noises coming from the carb area and when I looked I could see some moisture on the edge of the left carb boot which was bubbling like air bubbles coming to the surface rather than boiling bubbles. I think the moisture was some of the rubber grease I used to get the carbs in and out.

The need for the rubber grease is the other reason I'm replacing them.

Everything you say regarding mixture is pretty much what I've gathered through lots of research here and I'm kicking myself for not playing with the mixture screws this time. I did the highest RPM method years ago when it was on the road and it was great, I definitely should have done that again...

As to the float height, yeah that's a huge difference and I'm so glad I got that factory manual now. I still expect to have to lower the float height again once it's on the road given it will be richer than stock, but for now I just wanted to make sure everything has been covered off getting it to run right.

I think it will be a little while before I get to run it again now as I want to get a bunch of other things done towards finishing it and getting it registered.

 

[Guest]

Just a quick one here, I did my valve clearance checks and only had to change one, but I've put the 22.5 pilots in and put the mixture screws 2 turns out ready for whenever I get to kick it in the guts again.

 

[GsRocket]

Pete, have you figured out your jetting yet? I have a 1981 GS 450 ive been working on for the past year or so with moderate success. I'm also currently working on carb/jetting and have ended up with a 22.5 pilot, 144 main, float height is at 23mm, needle with 2 shims, and my air screws seem to need to be at different turns out(right at 1 1/4and left at 2). I have K&N pod filters and stock exhaust.
Currently i can get it to start and it seems to run fine(better and smoother than ever actually) at all throttle positions. then abrutly will stall after a minute or two... Also seems to take a few seconds to actually start up and get to idle.
i have 138 and 142 jet sizes for main, another shim for the needle, and my stock pilot. any advice would be appreciated i'm planning on tearing the carbs down this weekend
Right spark plug shows lean, left shows rich. also my mixture screw is an air screw not fuel.

 

[Guest]

Pete, have you figured out your jetting yet? I have a 1981 GS 450 ive been working on for the past year or so with moderate success. I'm also currently working on carb/jetting and have ended up with a 22.5 pilot, 144 main, float height is at 23mm, needle with 2 shims, and my air screws seem to need to be at different turns out(right at 1 1/4and left at 2). I have K&N pod filters and stock exhaust.
Currently i can get it to start and it seems to run fine(better and smoother than ever actually) at all throttle positions. then abrutly will stall after a minute or two... Also seems to take a few seconds to actually start up and get to idle.
i have 138 and 142 jet sizes for main, another shim for the needle, and my stock pilot. any advice would be appreciated i'm planning on tearing the carbs down this weekend
Right spark plug shows lean, left shows rich. also my mixture screw is an air screw not fuel.

Hey mate unfortunately not yet. I'm currently getting her ready for the safety certificate which means I'll be able to get her registered and on the road, so I should know how it's jetted in the next few weeks.

If you have the stock exhaust and K&N's, I'm really surprised you've had to go up in pilot sizes as everything I've seen and read indicates you should only need to play with the mixture screws in that scenario.

Have you done a full carb dip and clean and replaced all the O rings from www.cycleorings.com? If you haven't, I'd highly recommend it as it sounds to me like you may be working around some blocked or partially blocked fuel passages.

Also, with the stalling, if you take the fuel cap off does it solve the problem? If so, it's likely the little breather hole in the filler neck is blocked.

Just some thoughts from what I've seen along the way anyway...

I'll definitely update this thread with how my jetting is looking once I get her on the road again and start tuning.

Oh, and also, I'd highly recommend chucking an introduction thread into the GS Owners forum so everyone can say hi and BassCliff can you give you your mega welcome. And feel free to chuck some pic's in there too because we all like pic's

 

[GsRocket]

Tried the gas cap removed with no change
Dipped my carbs before i started jetting about a month ago, but i'm cleaning them again today and checking all the passages.
Initially before i did jetting i had the K&N's taped up(restricted) and it ran but was far from peak performance, with it untaped it wouldnt even start so i started changing jets. first i did the main and needle, but my idle was still extremely rough, and also it would occasionally stall after a minute or so at 3/4 throttle, seemed like lack of gas and spark plugs confirmed this
So i decided to up the pilot(for the idle) and the main(for the high end throttle). The kit i got from 6sigma initially didnt have a pilot, but after review he said i would probably need it and sent a 22.5 and also the larger 144 main(both for free.)
From what i've been reading though i'm thinking my pilot should probably be like a 20 and my main should be a size or two higher still. We'll see if the stock pilot will suffice for now though.

BTW got some pics up in the intro thread, check 'em out

 

[Guest]

Wow ok... no rust in your tank or anything like that? Or a restrictive inline fuel filter maybe? It just sounds unusual to have to do any of that with just the K&N's... the needle doesn't surprise me though as I believe they're quite lean "out of the box".

And did you do the O rings? They're rather critical...

Just thinkin' anyways...

And yeah saw your pic's, looks like a good start there

 

[GsRocket]

Wow ok... no rust in your tank or anything like that? Or a restrictive inline fuel filter maybe? It just sounds unusual to have to do any of that with just the K&N's... the needle doesn't surprise me though as I believe they're quite lean "out of the box".

And did you do the O rings? They're rather critical...

Just thinkin' anyways...

And yeah saw your pic's, looks like a good start there

Well there are a few rust spots visible inside the tank, and as far as inline fule filter you mean the petcock? i seem to be getting plenty of gas from the tank to the carbs.
And by orings you are referring to the mixture screws? i can't think of any others ive seen.

Speaking of mixture screws the OEM diagram shows an air screw, and then the "mixture screws" are just simply listed as a screw. Would i also need to adjust the air screw? and do you have any idea(or pics) where its located because the OEM pic is not real clear.
Also the mixture screws would be controlling fuel flow at idle correct? so if i had mine 3 turns out and the plugs are still white i would think i need the 20 or 22.5 pilot and the stock is just too small

I put everything back together with stock pilots and it did not want to run yesterday, throttle was sluggish and nonresponsive. but today it started right up and ran amazing. i road it(hauled ass) around my neighborhood for about 15 minutes to make sure it would stay running. There were some pops now and again which i think is because of excess fuel? but after tuning the mix screws in a little more it went away. So i decided to hit the open road and give it some truly open throttle. however about a mile or two out there was a loud pop out the exhaust the the bike stalled everytime i pulled the clutch in until i stopped. It wouldnt start again after that

I'm sure i'm doing something wrong but i can't figure out what. No one else seems to have this issue with jetting, where it runs fine and then you get it out there and it dies on you. I would think its too lean because of the plugs but i thought the super loud pops were from a rich mix

Might need to start a new thread soon....

 

[Guest]

Well there are a few rust spots visible inside the tank, and as far as inline fule filter you mean the petcock? i seem to be getting plenty of gas from the tank to the carbs.
And by orings you are referring to the mixture screws? i can't think of any others ive seen.

Speaking of mixture screws the OEM diagram shows an air screw, and then the "mixture screws" are just simply listed as a screw. Would i also need to adjust the air screw? and do you have any idea(or pics) where its located because the OEM pic is not real clear.
Also the mixture screws would be controlling fuel flow at idle correct? so if i had mine 3 turns out and the plugs are still white i would think i need the 20 or 22.5 pilot and the stock is just too small

I put everything back together with stock pilots and it did not want to run yesterday, throttle was sluggish and nonresponsive. but today it started right up and ran amazing. i road it(hauled ass) around my neighborhood for about 15 minutes to make sure it would stay running. There were some pops now and again which i think is because of excess fuel? but after tuning the mix screws in a little more it went away. So i decided to hit the open road and give it some truly open throttle. however about a mile or two out there was a loud pop out the exhaust the the bike stalled everytime i pulled the clutch in until i stopped. It wouldnt start again after that

I'm sure i'm doing something wrong but i can't figure out what. No one else seems to have this issue with jetting, where it runs fine and then you get it out there and it dies on you. I would think its too lean because of the plugs but i thought the super loud pops were from a rich mix

Might need to start a new thread soon....

Hmmm... ok I'm definitely seeing why you're getting confused... I'm not exactly a guru at this but I can definitely see some weirdness there...

If the plugs are white, I'd agree it's lean.

Is the popping during acceleration or deceleration? I thought popping on deceleration was a lean condition.

The 80 - 82 450 carbs don't have an air screw that I'm aware of, just the mixture screw. Winding it in (clockwise) makes it leaner, out (anti-clockwise) makes it richer. So, when you say you wound it in and it ran better, that actually made it leaner...

However, when you say you're giving it some throttle etc., that mixture screw is irrelevant, that's all needle or main depending how open the throttle really is.

Very generally speaking, closed to quarter throttle is pilot jet + mixture screw, quarter to three quarter throttle is needle jet and jet needle, and three quarter to full throttle is main jet. Of course they all influence each other as well but that's the simplest way of looking at it.

By an inline filter I meant in addition to your fuel tap's filter, but if you seem to be getting plenty of fuel then I guess that's not the issue...

Here's a couple of references I'm using in addition to all the stuff on BassCliff's site:

http://www.motorcyclecarbs.com/Jetting_Rules_of_Thumb_W43C551.cfm

http://www.motorcyclecarbs.com/Throttle_Chop_Method_W328C551.cfm

The other thing here is you may be chasing two different issues... perhaps you have an ignition issue along with a fueling issue?

My best suggestion right now is to start a new thread so you can hopefully get some more experienced heads in the mix...

 

[GsRocket]

So as an update i had it running again with good throttle response at all positions. however occasionally on decel it would make one very loud pop, not constant popping on decel like a lean mix makes. i rode it around for awhile like this before i started messing with the mix screws again and then it wouldnt run. i'm starting to think that this pop is essentially harmless(at least that it has nothing to do with jetting) and is due to the fact that my exhaust has two nice sized holes rusted out on the bottom. any thoughts?
Iv'e read a few others like this and i might get the mac 2-1 a little sooner than i thought if this is the case

 

[Guest]

So as an update i had it running again with good throttle response at all positions. however occasionally on decel it would make one very loud pop, not constant popping on decel like a lean mix makes. i rode it around for awhile like this before i started messing with the mix screws again and then it wouldnt run. i'm starting to think that this pop is essentially harmless(at least that it has nothing to do with jetting) and is due to the fact that my exhaust has two nice sized holes rusted out on the bottom. any thoughts?
Iv'e read a few others like this and i might get the mac 2-1 a little sooner than i thought if this is the case

Aaaaaah! I reckon you could be onto something there!

Those holes will have a definite impact. Not sure if they will cause the popping or not but I suspect they would at least contribute to it.

If I was you I'd be doing something about that to make sure your whole air/fuel system is in a known state before trying to perfect the fueling. As those holes get larger it will put your AFR out more and more...

 

[GsRocket]

Ok, here is my final solution.
My jetting is pretty close to where it needs to be, i could probably still go up one or two on the main. The real culprit was my dam manifold orings. They were completely flattened and stiff as a rock so i was leaking air through the manifolds the whole time. Also contributing was my petcock that was flowing at probably 60%. now that i have those two fixed it runs like a beast. If you can pull it off jetting is definately worth it. I'm positive my 0-60 went down by 2-3 seconds from where it was before and even my top end is higher(not sure how much since it stops at 85 but its very noticeable)
Thanks for the advice and if anyone every has rich jets but lean conditions ask them about the manifold o-rings it will save alot of headaches