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

[pete]

Emailed iwt.com.au to get the four jets ordered, fingers crossed this is what I need.

More fingers crossed my new intake boots get here this week. I'd really like to get them on while the carbs are off.

[KEITH KRAUSE]

I'm a little lost on your pilot jet situation. Not sure what you have or if the actual length/design of your present pilots is correct.
It DOES sound like lack of fuel at closed throttle position. Incorrect pilot jets would certainly do that.
Just to mention, I assume the diaphragms are in good condition? A classic symptom of damaged diaphragm(s) is the bike will idle but not accept any throttle or die if forced. Generally, the bike will still idle longer than what you describe so I'm leaning toward a fuel starvation problem.
My guess is no better than anyones about the needed pilot and main jets and I have no experience with how your pipe flows. If the pipe DOES flow as well as a quality aftermarket pipe then I'd start with a pilot jet that's 2.5 (1 step) richer. I'd allow 5 to 7 full sizes up (increase 25 to 35) for the main jets.
You also need to richen the jet needle position. You typically spend the most time operating on the jet needle circuit so that's important. Richening them 1 position is typically the minimum you need. Might need to be richer but test at solid 1/2 throttle position to find out. Check performance and check the plugs too.

[pete]

I'm a little lost on your pilot jet situation. Not sure what you have or if the actual length/design of your present pilots is correct.
It DOES sound like lack of fuel at closed throttle position. Incorrect pilot jets would certainly do that.
Just to mention, I assume the diaphragms are in good condition? A classic symptom of damaged diaphragm(s) is the bike will idle but not accept any throttle or die if forced. Generally, the bike will still idle longer than what you describe so I'm leaning toward a fuel starvation problem.
My guess is no better than anyones about the needed pilot and main jets and I have no experience with how your pipe flows. If the pipe DOES flow as well as a quality aftermarket pipe then I'd start with a pilot jet that's 2.5 (1 step) richer. I'd allow 5 to 7 full sizes up (increase 25 to 35) for the main jets.
You also need to richen the jet needle position. You typically spend the most time operating on the jet needle circuit so that's important. Richening them 1 position is typically the minimum you need. Might need to be richer but test at solid 1/2 throttle position to find out. Check performance and check the plugs too.

Thanks Keith, you're making lots of sense!

I posted the only Google reference I could find earlier in this thread that apparently says the actual pilots I need so getting those should be ok. I'm going to go 2 sizes up though to 22.5 given various things I've seen around the place and given that I know this pipe will breathe a lot easier than the stockers did. I got it made by a local exhaust mob here (Tranzac) that have a great reputation and you'll see a fair few Aussie bikes with Tranzac exhausts on them, so it should be a quality pipe.

The diaphragms appear ok, no rips or cracks or holes and the slides seem to move ok etc. and everything I can see indicates they should work.

The needles in these are adjustable and I have raised them one notch as a starting point already also.

At this point the aim really is to just get it to a point where it seems to run well so once I get it actually out and on the road I've got a good point to start from so I can then do proper tuning and get it running well.

I called the guys at iwt.com.au today to see what was happening as I hadn't heard back from the email I sent, and they just got back from Philip Island with a 9 ton truck of stuff to unpack, so hopefully I should hear tomorrow which means there's still a chance of getting some jets for the weekend.

[KEITH KRAUSE]

OK. Good luck with it.
I still think 2 full sizes up on the pilot jets will be rich. At the typical lower rpm's and throttle openings regulated by the pilot circuit, there's not so much change in flow that you need that much more fuel in the mixture. It may help to minimize decel' popping but I'd guess you'll see some puffs of dark exhaust when blipping the throttle off idle and the longer it idles the more it will build up. Less mpg is possible depending on your riding habits and maybe a stumble as you take off? Not trying to be negative. The bike may handle it without obvious issues but you can let us know and we'll all learn.
I just hope you get pilot jets that have the correct design.
Check the jet needles at 1/2 throttle. For pods and pipe, 1 position richer at the LEAST is necessary and I'll guess it may need to be set richer. Chop off and see what the plugs look like after testing performance.
Also, do you know what size main jet is in the DJ stage 1 kit for your 450?
The main jet in that kit is designed to run with the stock airbox LID OFF, correct? What exhaust is intended for use with that main? Just trying to get an idea of correct main jet size and if you know the above info then it would help to determine how much larger the main needs to be with pods vs airbox with the lid off. I still believe an increase of 5 to 7 full sizes larger is good but might be able to narrow that a little with more info. I've never personally jetted a GS450 before.

[pete]

OK. Good luck with it.
I still think 2 full sizes up on the pilot jets will be rich. At the typical lower rpm's and throttle openings regulated by the pilot circuit, there's not so much change in flow that you need that much more fuel in the mixture. It may help to minimize decel' popping but I'd guess you'll see some puffs of dark exhaust when blipping the throttle off idle and the longer it idles the more it will build up. Less mpg is possible depending on your riding habits and maybe a stumble as you take off? Not trying to be negative. The bike may handle it without obvious issues but you can let us know and we'll all learn.
I just hope you get pilot jets that have the correct design.
Check the jet needles at 1/2 throttle. For pods and pipe, 1 position richer at the LEAST is necessary and I'll guess it may need to be set richer. Chop off and see what the plugs look like after testing performance.
Also, do you know what size main jet is in the DJ stage 1 kit for your 450?
The main jet in that kit is designed to run with the stock airbox LID OFF, correct? What exhaust is intended for use with that main? Just trying to get an idea of correct main jet size and if you know the above info then it would help to determine how much larger the main needs to be with pods vs airbox with the lid off. I still believe an increase of 5 to 7 full sizes larger is good but might be able to narrow that a little with more info. I've never personally jetted a GS450 before.

Mate it's all good, I really appreciate the input and it doesn't come across as being negative

I'm not sure what the DJ stage 1 kit involves as I've never heard of anyone on here using one, but I believe it's designed along the lines of what you say with intake changes only.

I honestly expect to end up with different pilots and mains to what I'm ordering this time, so these first ones are really just a way to try to ensure it's got enough fuel flow.

I can't see me checking needle height and mains this time around as I still have yet to get it warmed up enough to do that important first oil and filter change and check the stator and R/R.

On a related note, I did a couple of other things last night.

First I moved my temporary fuel tank's outlet from here:



To here:



John picked up it was less than ideal as it has to syphon the first bit, so this way it's purely gravity feed. I'm still confident it was flowing through there due to my mouth full and float bowls full of fuel, but definitely better this way and I'm glad he pointed it out.

I also rechecked my float height because I didn't have the factory manual when I set them initially and figured it was sensible to do it as the carbs are off, and glad I did!



They should be 26.6mm for 1981 onwards, I believe the Clymer still has the 1980 spec's in it which are 22.4mm...

The camera batteries went flat so I didn't get to take a better pic but float height is now right:

[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

[pete]

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

[pete]

sorry you're right, heres the main
http://www.bikebandit.com/mikuni-sma...ck?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.

[pete]

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.

[pete]

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......

[pete]

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.

[pete]

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.