Carb Rebuild Complete - Dies on throttle

[Carter Turk]

For what it's worth I have an 84 1150ES with 36mm carbs, Dyno Jet Kit and K&N Pods, with a Yoshimura Pro Series II pipe.

Stock Jetting was 120 mains on 1&4 and 122.5 on 2&3
Pilot 45.

I purchased the bike already set up for stage 3.

It has 135 mains that I believe are Mikuni's, not DJ, so the size is probably similiar to a 140-42 DJ Main. The needle is set in the middle clip. (maybe one more down) 47.5 pilots, 2.5 out on the air/fuel.

Don't know if he changed the Air Jet or not and I've never checked the floats. The bike doesn't get ridden much as it's sort of my wife's ride. It a little hard to start after sitting for a few months, but when running it seems quite happy.

I think a 45 pilot might help with stalling at or near idle. I can't remember if you mentioned a different exhaust or not.

[pete]

Oh the things we used to do with a bunsen burner! was not that long ago for me lol so I still remember..haha...
I'll give this a crack tomorrow. Found a great vid on youtube which gave good info on this.

Its a car but its still valid.

http://www.youtube.com/watch?v=xEZ0-uN0NA4

Mate it's been well over 20 years for me... ha!

Very handy video actually, and there's some related ones which show the blue a bit better also, handy to see for sure!

[oohsam]

Chucked in the color tune on every cylinder and adjusted the mixture settings to a bunsen blue on idle. Worked out well. Did some plug chops after that. The tip of the plugs were a little white. So I'm sure its running a tad lean.

Decided to give the 45 pilots a go for idle, just to see if it was better or worse.
Was no good. Basically only had to turn out the mixture screws 1/2 a turn out. Probably running a little too rich. On carb 3 when I wind the mixture screw all the way down the flame was still blue.

When I would hold revs at 1/4 and 1/2 throttle, the flame was yellow/orange so thats lean. Decided to up the main jets also.

Removed the 45 pilot, pt the 40 back in and put the 142.5 main jets in.
Didnt have alot of time to color tune all cylinders, just did #1 and #4 (easy access!).
#1 cylinder was good at 2.5 turns, and when I would hold the revs at 1/4 and 1/2 throttle, the flame was a bunsen blue on carb 1. On carb 4 the flame was between orange and blue. Very strange.

I'm not sure if im spose to resync the carbs with my carbtune now that I've rejetted ??
But it looks like carb 4 is getting more air than carb 1 so I may do that next. And then adjust the mixture on all carbs because the bike is a little hard to start now. It basically cranks fires up and then dies unless I give it choke (even when its warm) then it idles ok. but getting it started is not as easy. So i think its vacum and/or mixture...

Then we'll see what happens on plug chops.
i really feel like im getting somewhere now and I actually understand whats happening.
Really owe GSR alot!

[hampshirehog]

Yellow / orange is rich. White is lean. When you use a colortune to test anything other than tickover you have to pull a couple of plug leads or the bike will rev it's head off.

You will always get orange (rich) if you blip the throttle by the way (and the bike is close to being in tune).

[oohsam]

oh snap! ok. Had it backwards.
so i need to turn the mixture screws to ich then stop at the point where it goes from rich to blue...that would be spot on, too far and it would be lean.
maybe thats why im having trouble starting it!

will try tomm. morning, cheers

[pete]

It does sound like you're getting somewhere!

Also, don't make the same mistake I did. If you've only warmed her up by idling on the choke, then she's probably not warmed up right and none of your checks at idle will be accurate. You really need to take her for a 5 or 10 minute run to get her warmed up properly. That's why I ended up with +4 sizes on the pilots and running waaaaaaaaaay too rich...

[Carter Turk]

So the original post says nothing about an aftermarket exhaust. Are you running pods with a stock exhaust?

[oohsam]

OH i thought I mentioned it!

Yes I'm running a 4-1 that came with the bike

[oohsam]

For what it's worth I have an 84 1150ES with 36mm carbs, Dyno Jet Kit and K&N Pods, with a Yoshimura Pro Series II pipe.

Stock Jetting was 120 mains on 1&4 and 122.5 on 2&3
Pilot 45.

I purchased the bike already set up for stage 3.

It has 135 mains that I believe are Mikuni's, not DJ, so the size is probably similiar to a 140-42 DJ Main. The needle is set in the middle clip. (maybe one more down) 47.5 pilots, 2.5 out on the air/fuel.

Don't know if he changed the Air Jet or not and I've never checked the floats. The bike doesn't get ridden much as it's sort of my wife's ride. It a little hard to start after sitting for a few months, but when running it seems quite happy.

I think a 45 pilot might help with stalling at or near idle. I can't remember if you mentioned a different exhaust or not.

really appreciated that info, helped out quite a bit!

[oohsam]

By God, I think I've done it.

#40 Pilot (Stock)
#170 Air jet (stock)
#142.5 Main jet (not stock!)

I think its running a tiny bit rich in the mid-high range. Which is ok, because I can always go down to a 140 main if required. But I will do more testing to ensure Its running right.

When I hold the RPMS on the bike at 5k with the colour tune, the flame is yellowish/blueish. Its not all yellow but not all blue...So That tells me richy rich.
Also I get a tiny backfire/pop every now and then, so that would be unburnt fuel?
One other thing I noticed happens sometimes. When Im holding a constant speed, a pop comes from the air filter. I have no idea what that is?? Has anyone seen/heard this before?

But other than that, the bike is pulling hard (apart from when I was running out of fuel and started thinking i've stuffed something but just had to switch it on reserve tank!)
and It starts up with ease.
Took a little while to colour tune it. Each carb is running a little different (x number of turns on mixture screws) but as soon as the flame turns blue from yellow, i stop and that is the right mixture. See my youtube vid for more fun.

http://www.youtube.com/watch?v=RbU67WGHR1A

[hampshirehog]

When I hold the RPMS on the bike at 5k with the colour tune, the flame is yellowish/blueish. Its not all yellow but not all blue...So That tells me richy rich.

Disconnect your tacho. Put tape over the glass. Anything. IGNORE the rpm - you won't tune a thing in if you're looking at that. It's throttle postion and throttle position alone that you use.

Did you disconnect a couple or 3 plug leads when you were holding the bike at 5k? If you didn't then you were still on the pilot circuit - otherwise the RPM would have been well over 10k and you would have had the neighbours round complaining.

[pete]

Disconnect your tacho. Put tape over the glass. Anything. IGNORE the rpm - you won't tune a thing in if you're looking at that. It's throttle postion and throttle position alone that you use.

Did you disconnect a couple or 3 plug leads when you were holding the bike at 5k? If you didn't then you were still on the pilot circuit - otherwise the RPM would have been well over 10k and you would have had the neighbours round complaining.

I'm hoping I can get away without pulling a plug on the 450... if I do it at the right time of day it should be nice to hear her roar

Might still need to do it for 3/4 and WOT though

[oohsam]

The 5k was basically at neutral.
Correct me if I'm wrong, but if my 1/4 throttle is 5,000rpm in neutral, then its 1/4 throttle regardless.
My point being, The only reason we use throttle position is to ensure that we inform people to open it at throttle for the selected gear they have...therefore, 5k rpm @ 1/4 throttle in neutral, is the same as having 3k rpm in 2nd gear at 1/4 throttle....

I just use RPM as indication of how how far I am opening the throttle in Nuetral..

I didnt pull any plugs...I ran all 4 plugs, and yes it was hella loud, but quite nice.
My neighbours love me (i am the resident IT guy, TV tuner, and dvd connector) so they put up with my nonsense! lol.

one more thing, wouldn't pulling the plugs throw the vacum out of whack?
Just a thought.

[oohsam]

If you didn't then you were still on the pilot circuit - otherwise the RPM would have been well over 10k and you would have had the neighbours round complaining.

Why would it still be on pilot circuit if the throttle is open 1/4 in neutral?
Did I miss something?

[oohsam]

Oh one more thing,
I did a plug chop at 1/2 throttle earlier, plugs were a little wet. Not much, just a tad, so I will be dropping main jet down to 140.