Idles between 5000 up to 7000 rpm. HELP

hello, thank you for looking at my post.

Here's is what's going on. Also if you need anymore information just ask

I have a 1982 xj650. It has a little over 30,000 miles on it.

When I start the bike up it reeves right up to 5 - 7,000 rpms. When I touch the throttle it does nothing with the rpms.

It also seems I'm not getting any fuel whrn the petcock is on the on position.


I'm assuming I have a vacuum leak somewhere.

I've sprayed all the carb boots with cleaner and I'm not getting any change in rpms or sound. Where else should I be spraying to check for vacuum leaks.

Also I tried adjusting the idle screw with no change in Rpms. And checked the choke cable and throttle cable for slack and clearance. They seem to be fine.

Any help would be greatly appreciated

 

is the throttle linkage on the carb moving properly?

what work was done on the bike?

 

Any difference if the choke is on or off?
Was the bike running well recently? Or is this a recommissioning effort?

 

@XJ550H. Thanks for asking
Yes. the throttle linkage moves properly.

The carbs was recently rebuilt. Before it was leaking gas into the airbox. Fixed that by cleaning and rebuilding carb.

 

@Stumplifter thanks for replying

I do not notice a difference with the chock on or off. It jump to 7000rpm. Right away when I start it.

When I first got it. It ran for a few miles. Than started to leak gas. So I pulled the carbs cleaned and rebuilt it. From what I've been reading in the forum it could be a vacuum leak.

 

Did you replace the throttle shaft seals when rebuilding the carbs?

 

Did you do a good bench sync when you had the carbs off? Are you sure there isn't a linkage issue? Disconnect the throttle wire at the carb and see if that makes any difference.

 

Did you maybe hook the cables up incorrectly? Wouldn't be the first time that a throttle cable and choke cable were swapped.

 

@TheCrazyGnat. I did not replace the throttle seal when redoing the carb. Do you think that's where the leak is?

 

@tabaka45
I will try disconnecting the throttle tonight and see if there is any difference and report back

Thanks for replying

 

@kmoe I will check on that tonight and report back. Thanks

 

I think it is a possibility, I would spray around them to see if there is any change. I would definitely try the other items mentioned above. The complete lack of throttle response seems to point to something besides just a vacuum leak, although it could be part of the problem.

 

So update. I took the throttle cable off and the bike ran the same. I put throttle back on and then took the choke cable off. The bike isn't revving up to 7000 rpm. I have it to idling 1500 to 2000 rpm or even less. I still really have no throttle I'll open it wide open and no change in rpm. The cable is tight and lifting. But still no change.

Any thoughts would be greatly appreciated.

Also I'm gonna spray throttle seal tomorrow and see if it's vacuum leaking there.

 

Another possibility is that your throttle cable is not routed properly (over the handle bars, through the woods, under the tank, alongside the frame . . . ). Try starting bike and turning you handle bars fully left and right, you will know pretty quick if the cable isn't on the right path. Trust me I know.

If not a routing issue:
When you release the throttle after full twist does it "snap" shut?

What exactly is the throttle cable lifting?

I'm going where Kmoe is, taking the cables off isn't verifying their locations. If possible upload a picture of your throttle cable and where it is attached to your carbs.

 

This is my first thought, too-

BUT, give us a couple pics to examine

 

Here's some pictures you were asking for. Throttle cable attachment


1st pic. Throttle cable attached to carb

2nd pic throttle fully turned
3rd pic. There's some play in throttle. Can turn throttle forward.

No throttle.


With throttle

 

Also here's throttle cable too
1.

2.

3.



Thanks for any help or thoughts.
Tim

 

The last two pictures are your choke plungers. If the throttle lifts those plungers then you do indeed have your choke and throttle cables reversed.

Last two pictures in first post.

 

BigT is correct, the throttle cable should be connected through the 'tube' that is in between carbs 2 and 3 (just behind your current connection in the first picture).
There is linkage that is connected to the butterflies, so when you release the throttle, you should here those snapping closed.

The angle that the throttle cable is coming off the handle bars doesn't look correct. Is that a new cable? Whom did you get it from? Was the old cable routed the same way?

 

Timmy, is this bike relatively new to you?
It appears that there is an incorrect MC/ or different handle bars on it (the reservoir should sit level) and the braided stainless steel line looping back under the tank would indicate an incorrect length (may or may not be a problem) but certainly a concern if it were to tangle/ snag with something.

 

Your cables are indeed at the wrong locations.

And-- I am also suspecting you have the cable themselves on the wrong levers.

The throttle cable (with the metal curved tube by the control) is the throttle cable. It rests in the cu- of the bracket in the middle of the rack, as shown. The 'ball' on the end of the cable goes down into the rounded part of the linkage below the 'cup'

The enriched cable goes from the bottom of the left control to the clamp on the right side of the carb rack Picture.

 

The bike is brand new to me. I've had it less than. A month. And only rode it once. I feel stupid for asking but what is "MC" ?

I also swap the cables so they are correct and it's running normal now. With the throttle working

 

You were right they were backwards

 

You were absolutely right. Thank you

 

The cable might be new. But it's not new to me it how I bought the bike. im not sure if it was routed that way. I had my dad take the carb off the first time

 

1. Congrats on finding an XJ.....stay here, ask, read, learn......DO. You'll be fine and and up with a bulletproof bike that you can be proud of.

2. DO NOT feel stupid for asking any questions. You only find out the answers when you search or ask. If you're willing to listen and learn, we're always here to help.

3. MC stands for Master Cylinder

4. Glad you got it figured it out

Dave

 

That really doesn't matter......you will find out this rule:

NEVER trust what a previous owner (PO) SAYS he did, and never trust ANYTHING until you verify it is correct

So just because it came that way, doesn't mean it was correct. Case in point with your cables. You've already fixed one thing. Congrats on that!

 

Thank you so much Dave.

This forum is so welcoming and extremely knowledgable. So willing to help. You guys are a life saver. I won't be leaving this forum anytime soon. You and everyone else on the forum I would like to thank again. You guys are a life saver.


Thank you so much

Tim

 

I have another issue with my bike. I don't really now anything about electrical

When I bought the bike none of the turn signal work at all. Do not turn on or flash.

Someone put after market signals on it.

The bulb size they have in it is a 12v10/5w bulb.

I was reading on another thread that xjbike that I might need a 27w bulb.

Pic attached is the bulb p.o had in it


Any help or thoughts is greatly appreciated.

 

Yes the flasher unit needs 27w bulbs to function properly.