HELP!!!!!!Jumping idle83xj750 to 83xj650

I recently switched my 750 (90kmiles) motor out and put in my 650 (20kkmiles) when I turn the idle screw up to idle and blip the throttle it jumps in rpms and stays there for a bit before coming down
When I turn it down so I gotta hold the throttle to stay on I blip it and it does the same thing
It's got kn filters 4 into one with a custom exhaust with baffles
It had 130 jets but those were too big I switched to 117.5
When I ride it she rips but stopping when the motor is going full blast is scary
It's the 5th motor I've owned
I need help
Anything
I'll try anything

 

Both are yics
Also by a bit I mean 30 seconds
It's got dyna coils
The tdi from the 750
Oil cooler from an xj 900
fresh oil n filter
I used my intake boots from the 750
Hitachi carbs
I've been working on it for over a week now and its driving me bonkers any assistance would be greatly appreciated

 

did the throttle stick in 750 motor?

 

Its lean man. Check for air leaks. Does opening the pilot screws help the issue?

 

""It's got kn filters 4 into one with a custom exhaust with baffles""

I wonder if he is saying pods or the oval filters and not using air box?

 

He says "filters" plural so I am figuring Pods.

I worked at a Suz/Kaw/Tri dealership for a few years...I hated all the jetting problems I had to work on when customers fitted filter pods to their bikes. And of course, you couldn't tell them that it would never run right...but when they got the bill for 14+ hours of labor an 6 different jet sizes x4 carbs...they didn't want any part of it. I swore to myself that if I ever owned a bike with CV carbs...that I would not modify the intake tract!

EDIT- when you say oval filters, do you mean the "pods" that two carbs share? I see little difference between those and 4 separate units, have you in your experience?

 

It's 4 pod filters
Throttle doesn't stick
Carb butterflies open and close normally
Everything seems to move fine
The muffler is off a 03 Honda shadow 750 ran better than the one that comes with the 4into1 exhaust
So I should jump up in jets?
The mixture screws are jammed but they ran fine when on my 750
The boots are sealed don't think I got a manifold leak but I bought new gaskets for it anyways

 

You have air leaks . Throttle shaft seals or carb to head boots are leaking. Could be one or both.
I bet the idle jets are different between a 650 and 750 motor. Since you cant adjust the idle mixture you are probably running very rich. Seems to me you need to tear the carbs apart and fix the stuck mixture screws and check the pilot jet sizes.

 

Maybe air leaks. Pods make everything lean. Pods are the devil.

Put the factory airbox back on, and jet the carbs to stock 650 specs.

 

The idle jets are just about the only jets that are the same.

 

yes that is what I mean, no experience with them . we had a member attempting to use them but he hasn't been around for a while with an up date on his K&N set up

 

The 750 ran great with 130 main and stock everything else
The 650 and 750 pilots are the same I'm pretty sure too
The factory air box won't fit.... it's in a molded hardtail frame
I'm gonna put the 130 back in and try it also gonna spray it with water to see if I can find a air leak

 

lol don't spray it with water to find the air leak, spray it with carb cleaner/brake cleaner/contact cleaner/etc.

 

I got an intake boot leak
Do the
YAMAHA 78-81 XS1100 82 XJ1100J MAXIM
Boots fit the xj 650 or
83xj55 boots fit?
I can't find any online for the 750/650
Is there a better way to seal them to the motor besides the gasket?

 

Start a conversation with Chacal. He has what you need. The intake boots from the 650cc and 750cc YICS engines are the same. Be mindful of which boots go where; they ae not all identical.

The gasket is the preferable method for sealing the boots to the head, but they do occasionally require a gasket dressing to get a good seal.

 

I got the gaskets they aren't sealing what kind of dressing would you use? Ranch or bleu cheese
Also how do I start a conversation with chacal? The boots are good I've tried to get these gaskets on right 3 times
Thanks again everyone!!!!

 

Hover over your name at the upper right of the page header. Click on converstaions. Click on start a new conversation. Type in the relevent information.

Permatex Copper gasket dressing is my preference.

 

[QUOTE="k-moe, post: 507128, member: 11887"

Permatex Copper gasket dressing is my preference.
[/QUOTE]

I prefer Ranch...

 

Permatex Copper gasket dressing is my preference.
[/QUOTE]

+1...it's what I use also. Apply it to the non-engine side of the gasket only or it'll be a pita in the future trying to get them off.

Gary H.

 

Sync the carbs

 

Love that stuff. Has saved my butt a few times. Had a bike with a head that was a little less than flat, kept blowing gaskets and leaking coolant...no matter how much time the head spent on the glass plate, it just always leaked. A heavy coat of that stuff on both the head and the cylinder, as well as both sides of the gasket...let it dry...assemble...no more leaks. I use it a lot when I re-use base gaskets and such too. Great product.

 

81 Xj 650
Turns right on no problem
When i bring it to idle and ride it when i let off the throttle the rpms stick for a second before settling down slowly. Like if I have to let off to brake it wants to keep going. With no idle (screw backed all the way out ) I have the same issue until it settles and shuts off.
Got new intake boots and boot to head seals
Rebuilt all 4 carbs completely.

 

Did you break the rack and replace throttle shaft seals? Sounds like possibly a vacuum leak to me and throttle shaft seals are a common leak point

 

Is this a different bike, or one that you've posted about before (your engine-swap machine maybe)?
I only ask so we can have an idea of the history of the machine.

 

Kmoe yes this is the same bike got a xj550 I've been scooting on.
Yeah it's a 81 650 motor in a 83 750 frame. Yes I actually just did them had a bit of trouble with the shaft seals sealing but figured it all out well at least I thought I did. Yeah air leak is What i keep thinking too. The shaft seals are all new and all facing outwar. Is there anywhere else these carbs like to leak?

 

OK. I'll merge the two threads then.

 

Thank you for merging them .
Looking back at the thread I'm still in the same boat.
I took the rack a part and replaced the shaft seals had a little issue with them sealing but they seem good now. Hmm I guess it could be the boot to head. I'll pull the boots and seal them to The head again.
The idle jets are the same between the 650 and 750
The carbs are synced
I rejetted to stock and worked up from there to get it to run right . I've done a lot of jetting on these bikes over the years.
I got 4 pods
The air box won't fit in this frame or I'd already have it on.
I know it's an air leak I'm just getting discourged nothing has ever taken this long to figure out lol.

 

Should I drill out and replace the mixture screws? I just dont wanna make my issue worse

 

Drill the caps off if they are still there? Sure, but I'd test for leaks with carb cleaner first.
Are the enrichment plungers seating fully?

 

Please explain more about the issue with getting the throttle shaft seals to seat.

Do as Kmoe suggest, carb cleaner sprayed around carbs and boots while running to see if the idle changes. Not sure of a good way to keep overspray out of the pods.

Did you perform a running synch or just a bench synch? Colortune needs to happen, then a running synch... that is after you are sure your valve clearances are correct. And you are sure about your jetting for your pods.

 

At first the shaft seals were poping (letting air out) seemed to me that the eclip and washer weren't pushing against the seals on the outside carbs (which is why I replaced them in the first place) i placed a tiny oring that fits inside the v part of the seal and the popping stopped. I had taken them off and apart 4 or 5 times at that point.
I'm off tomorrow I'll grab some carb cleaner on the way home tonight I'll just be careful spraying so I dont get it into the pods.
2 of 4 mixture screws move I just have two jammed one's I've never touched any of them
I checked and the carbs are synced while running which could be my fault
I synced them the first time I was having these issues. The motors good i got new plugs filters before running it got the jets right before this issue came up or i guess became recognizable

 

Putting an o-ring into the seal V-noch will compromize the seals.
If the seals were popping out of their bores, then something is wrong and must be addressed.

Time for teardown and pics.

 

See that's exactly what I was thinking
Like I said when I put them together they all were popping I took em apart tried again and only the outside one's were popping (which they were doing before I put the new seals in.) I finnaly put an oring in the outside carbs after about the fourth time I took them apart.
The eclip and washer dont seal against the seal. Like it's super loose. Are you saying I need new shaft seals ? Cause that be my third set on these carbs lol

 

I'm saying we need pics to get a clear idea of how to help.

 

Ok ok sweet I'll have em apart first thing in the morning gonna test em with carb cleaner first. Thank all of you so much

 

So as I took them apart I realised the two inside carbs the butterflies wouldn't close fully (well to where the idle screw sets em not exactly closed) they were hard to move in general I took all the carbs apart cleaned all the internal parts butterfly valves therittlw shafts springs that weird spacer on the inside carb which to be honest were sticky and pretty dirty......Also I removed the orings and the outside carbs didn't pop. the two inside carbs were popping and when I took em apart #3 I didn't tighten corectly and #2 would jam about 1/4 of the way from the idle spot. I'm waiting on the rain to stop before I slap em on and test em Damn Florida weather.

 

Idle is crazy high. Nothing I do with the idle screw or sync screws changes it. Its way to high to check anything. Way way worse than before

 

That's the washer on the far left carb should there be a space that big between it and the body of the carb?

 

Could this be my issue? This is a brand new seal and it's kinda open on one side is that ok?

 

I thought you said that you cleaned the carbs.
In my book that means a full teardown and dip.
Your set does not look like they were dipped.

The seals won't seal if the parts that they mate to aren't clean and smooth.
Carb cleaning CAN'T be a half-done job.

 

He speaketh thy truth. Amen.

 

Where did you get the seals from?
That one looks like it's malformed. I think I see a blob of rubber connecting the two sides of the groove.

 

I got the seals from here i couldn't find anywhere else that even mentioned them. I cleaned the inside and your right I need to clean the outside of them all thoroughly.
Can someone outline the exact reasselbly steps on the butterflies I wanna make sure I'm doing it in the correct order.
Yeah that's what I was saying the seal seams a bit wierd on the shaft.

 

Sorry I've been gone my uncle died and my father got diagnosed with the same cancer that took his brother life has been lame I just wanna ride my bike again.
Anyone know a place or person that'll rebuild these carbs ? I can't figure this out alone.
Had a shop around town say 600 plus parts which is in my mind a bit much.

 

Sorry to hear about your uncle and father, what a rough road......600 is stupid crazy! Start a conservation with hogfiddles on here, from what I have seen and read, he can make your better than new.