3rd gear, 6,000 rpm = 90 mph?

[underdog57]

I put some screens in from parts carbs .
The float levels were off , so this time i went 26MM and rotated the carbs to cycle the needle valves . . The tangs are bent in a way that makes then seem unstable ...the needle valve kinda rides where the tang gets bent at quite an angle ....

Will throw them back on !!

Bob

[John]

Bend that tang so when they are full open, the needle won't get cocked. That will help prevet a flooding conditiom when you first fill them with fuel.

[skids]

Or if it is the 79, you should be aware that some of the rebuild kits has fiber washers that are too thin. Get some more (Lowes) and double up on them if needed.

Originally posted by John
Bend that tang so when they are full open, the needle won't get cocked. That will help prevet a flooding conditiom when you first fill them with fuel.

[underdog57]

Hey skids and John ,

I put them back together before i saw your posts . I did raise them to 26 MM . The bike runs a lot better . It idles down quicker .
Funny how I did the level check with the tube and they were in spec . they must of not been settled in place . I'll do that later again ...

I still get stuttering , but a lot less . kind of lugging it when that happens .
These carbs are off an XJ .

I'll try syncing and idle adjustment again .

It pops when I let off the throttle , it did not do that when it was rich (float rich) My guess anyways ...

Getting good at removing the air breather !!

On Pats Bike , From what it sounds , he might just need to do a real sync ... Eyeballing was pretty far off when I did the sync with the looped tube with trans fluid tool ...

Be great to have the real one as this is a bit tedious , but did do well . If the carb was off enough it would suck the fluid up .
I got by that buy shutting the bike down , turn the screw till the leval was reasonable . One pair was close to begin with ..

Will ride and keep messing with it !!

Bob

[trbig]

And just for grins....

This afternoon I checked... and 3rd gear at 6k rpm is right at 65 mph

Tod

[audijunky]

it may just be me, but it sounds like both of your bike are running rich. How do the plugs look. I had the high idle problem as well and it turned out 2 of my cylinders were running rich. Also a good sync would help. How many turns out do you have your idle mixture screws ? Both bikes have previous owners, so have you checked to see if the idle mix hole in the throat of the carb has bee drilled? This can cause a rich condition. I may be wrong but I think you guys are looking in the wrong place by looking for vacuum leaks. That would cause the bike to run lean/get real hot. Any one else out there to back me up on this?

[Incubus]

My bike is indeed running rich. The plugs are coming out sooty. That was one of the things I was having a hard time reconciling with the lean condition a vacuum leak would have caused. I also am running a UNI foam filter in the stock air box. My last conjecture was that it was getting too much fuel and, with the easier breathing of the foam filter over stock, the engine would race until I backed off the throttle so much that air flow was too low for it to run.

The hole in the carb bodies where the air needle jet lives looks to be stock. It is very small, anyway, much smaller than any of my drill bits. Just big enough to poke through the end of the dental pick I use for clearing out very small holes in the carb.

My air screws are turned 1.5 turns out. To lean it out I screw them in, right?

I discovered an anomaly when I tore down my carbs - again - yesterday. Wrong emulsifiers in three carbs. That is addressed, but I suspect I will still need to play with the fuel mix.

By the way, Tod, I believe the 90 mph, I don't believe the 6,000 rpm. I was flashing around cars too fast for my speed to have been anywhere around 65. They were like traffic cones.


Patrick

[randy]

Patrick,

Just random thoughts....

Are your carbs properly vented? two upper 'tee' hoses vent to the airbox. The ports in the airbox need to be clear of obstructions. If you've fitted a later airbox, those nipples need to be drilled out.

[DiverRay]

Patrick and Underdog,
The SYNC is a VERY important part of the set up. If one carb is out, it will pull every other carb up in the idle mode. On the '80 carbs, you have an "O" ring that seals the seat. I would be SURE it is NEW, and not torn. If in doubt, replace it. On both the '79 and '80, verify that the floats WILL NOT hit the side of the float bowels, as that may cause them to stick, and over fill the bowel. The float level is critical to the idle and high speen running of the bike.

[underdog57]

I'm Rich( carb)

I synced with the looped tube w/trans fluid home tool

Some how my floats seem to have settled too low after running it . I went for 26MM this time . Also rotated the carbs to try to get the needles to get situated . the tangs are bent at quite an angle
with float closed ...did not look how they sat open position ...

Put new float needle and seats in the 82 xj carbs , bike is the 79 special stock air box.

Needle seats are the same from mikes xs I'd guess .

After I reset the floats I bravely took a 1/2 hour ride .
It runs a lot better , idles down quicker , slight lingering rev .
I want to resync and adjust the idle mix screws next ...
The plugs looked a lot better , 1 and 4 were black before .
Not crazy about the tangs on the floats still ....

It still did break apart around 4K to 5k at the reset level.Seemed less though .

Ealier float setting (rich, rich) When it fluttered 4k to 5k I opened the enrichener and it still fluttered.Broke up rough ...

Another thing it does now with the lower fuel leval is it does the exaughst popping when you let off the gas and the engine slows you down . rich I did not notice that .... popity pop pop pop .ahem , you know what I mean ....The headers must make that pop more ...Stock 79 airbox no holes drilled yet ...

My idle screws are set a two turns out from light seat .
All the jets looked stock and not drilled , just gobbed with goo...
Cleaned and cleaned everything , new shaft seals etc etc..

I did not have time to try anything but look at plug color after the last float adjustment , but it was night and day differant looking plugs and running ...

Hope this helps patrick out too !!!
Thanks for all the thoughts on this !!

Bob
I should take off from work this is getting interestingly close!!

[DiverRay]

Underdog57,
Sounds as if you are close. I think you may be just a little off on the adjustments. Have you looked at the tech tips from the MAIN forum page? there are some about doing the final adjustments for the pilot screws. I followed that on my bike, and it helped with the creeping idle. I have a header, and DO get the de-acceleration pop.

[trbig]

By the way, Tod, I believe the 90 mph, I don't believe the 6,000 rpm. I was flashing around cars too fast for my speed to have been anywhere around 65. They were like traffic cones.

Just think..... two more gears!! lol..


I hope you get it lined out right.

Tod

[underdog57]

Hi Ray ,

Yes , looked in all tech areas over and over !!
Last time I synced and tried the idle setting . the idle screws seemed to do nothing . hoping its from floats too high .
Will go over re- sync and idle mix wednessday ...

It did seem to be a big deal with the new float height , and I hope they stay put this time ....

Put hi-test in last fill up , and have been putting a good dose of sea foam in . Working the bad RPM area with throttle up and down to try to see if it will help clear it up ....

Would like to get out of playing with the emulsion jet needle??

Will post results asap
Getting very excited , next set of carbs will be a walk in the park !!!

Thanks All great help !!
Bob

[audijunky]

underdog,
do you have any mods on your bike? you said something about headers? exhaust? do you have pods, or airbox? If you have an airbox do you have K&N filter? You said you have looked at the tech tips did you follow the jetting reccomendations for the mods(if any) you have?
The tang on the floats your talking about, That is the part that pushes the needle into the fuel inlet correct?
If your idle screws do nothing than they are probably too far out which would be rich at idle. If I were you I would set everything back to the stock settings except for following the jetting guides for any mods that may apply. Then adjust one thing at a time. I know that sucks, but thats just what I would do.Set your idle screws to 1 1/2 turns out. Also check the holes in the throat body for the idle mix screw to see if they have been drilled or not. I had to drill mine, and my idle screw is a 3/4 turns out.So you can see how I was running rich with the stock 1 1/2 turns out. If not drilled I would set them at 1 1/2 turns out and do a sync following the guide in the tech tips.
Good Luck

[underdog57]

Hi Audijunky ,
Thanks for the tips ...

Stock airbox and Winning Four into 1 headers ...Believe the filter is stock , no holes drilled in air box ....
I'd guess the idle screw bores are stock too ...Tiny...

All jets are stock xj carb ....
I'm going to resync and try the idle screws again , before modding
any jets . The floats were a few MM too low after the ride somehow. Since have readjusted . Huge differance .

I adjusted the new float to go full open the same distance as the originals with a limit tang .
The float Height tang I've been talking about is the one the float needle wire hangs on ...

The way it had heaps of over 5k power I wonder if I need to mod the jetting ?? Was xsilerating !!! Of course it was running float rich then . But it might be best to try WOT with the new float setting before jet mods??? The last float setting is in spec. also

If I knew what I was doing like a pro this would be done months ago ...

Bob