Totally messed up Jets

So i pulled my carbs again today. Its going to be raining for the next three days, so hey, why not. And I'm checking my Jets and Re-setting float levels cause there is popping in my exhaust. When I first pulled apart the carbs I guess I was stupid and never asked about the jets. Figured "Hey, it runs, why mess with it?" Check this out...

Main Jet #1
110
Pilot Jet
365

Main Jet#2
107
Pilot
40

Main#3
I <i>think</i> its a 110. Thats the one thats messed up
Pilot
40

Main#4
107.5
Pilot
365

So I need order new Main jets. Do you think I should stick with the stock 107s? or go up a size?

Pretty messy... What do you guys think? Could this account for my many turns out on some of my pilot screws? And possibly the popping noise at 3K RPMS?

-StreetLegalKid

 

I think what I'm going to do is move the main jet 3 to 4 so it'll semi-match the others and see how she runs. Still going to adjust floats. Wish me luck!
-SLKid

 

Oops! Typo My Jets are as follows

Main Jet #1
110
Pilot Jet
365

Main Jet#2
107
Pilot
40

Main#3
I <i>think</i> its a 110. Thats the one thats messed up
Pilot
365

Main#4
107.5
Pilot
40

So I'm going to switch Main and Pilot with 3 and 4, see how she does

 

Ok, checked all my Floats. Dead on 17mm all four. So, i dont think that was the prob. I did some reasearch and it looks like the 110s and the 40s came from a 650 engine. the 365 and the 170s are stock XJ700 jets
I keep finding a TON of mismatched parts in my carbs. Its ridiculous.
So i took the 110s and the 40s on the ends cause they're larger, and those cylinders tend to like to run on the rich side anyway. And placed the 170 and 365s in carbs 2 and 3, cause those are the "pilot" carbs I guess you could say. 1 and 2 are married pretty much and 3 is the real determiner of what your bike is doing. You "main" carb i would say. So... lets see how she rolls now.. Crossing fingers.
-SLKid

Still gonna buy new jets though.
Lol, and sorry about my posts! Its kind of a "keep myself on track" method by writing everything down. My own personal monolouge. lol.

 

I doubt it's ever going to run right without the right jets.

Not sure, but I think with the mixtures being different for each cylinder, you run the risk of warping the head with the uneven temps.

 

I'm sure she wont sir. I am purchasing new jets as soon as Chacal gets back to me. I'd like his expert advice on either going with stock jets or uping them a MM or two. We'll see what he says and as soon as I get the parts in the mail they're going in. And then back to syncing and tuning.
A warped head does not sound like a good time btw...
-SLkid

 

I think (and i could be entirely off base here), but didn't the midnight maxims run different jets between 1&4 and 2&3. I know thats where my carbs came from and they have odd jest - similar to yours SL. It's been running top notch like that for atleast 10+ years, so I wouldn't worry about warpage.

 

Exactly Ace,
Chacal will know for sure but I'm pretty sure the 700n or X ran different jets on different cylinders.
It should be in your manual.

 

The Chacal Bubble Bursting Hour, brought to you by.........

Yamaha, in a mutually beneficial partnership with the Hitachi Corporation.


Float HEIGHTS don't matter. Fuel LEVELS do.

Yours should be 1mm +/- 1mm using the procedures and methods outlined in the service manuals using the "clear tube" method.....


As far as I know, and it's somewhat debatable becuase different factory sources reference different figures, but the only bikes that use different sized jets in different carbs is the XJ650 Turbo models (at least, in our era of bikes).

The 1984 XJ550 model....which, though technically one of our little XJ's, is so uncommon as to not really count....actaully used three different sized jets amongst it's four carbs.

 

Should probably invest in a manual

 

We wet tested the last 550 carbs on a jig I made to hold carbs in my shop. We used washer fluid "Like Big Fitz Does" and nailed the float levels. Even at 17mm you can't rely on that. The floats could be bent or something. It worked great and the member is going to fire his bike up soon and post picks of what and how we did it.

 

That'd be cool MN. I think i should jsut go ahead and do a clear tube test.

I think mixing up the jets had an adverse effect on my Bike. I rode her to 711 today to get gas, and when i got back I was gonna check her plugs. So I fill up and go back out to start her up. She was trying SO hard to start. I had the choke completely closed and held the starter button for like 3 seconds before she started.
The switching of Jets is letting too much gas in for her to start??
I'm not sure what I should switch them to after this. Hmm..
-SLkid