Throttle cable and overreving

I thought I would start this thread to ask if anyone has had this problem before me and if there are any tips for me before I start searching for a solution.

First the bike + obligatory pic: 1984 Xj900RL

Recently I had the carbs off my bike and gave them what I considered a good clean. Being the first time I clean any carbs, I probably did not do it good enough but the bike runs afterwards. I did´t do a bench sync just in anticipation that this question comes up

I noticed a rather annoying and potentially dangerous development recently.
When I turn the handlebars to the right fully, the bike start to rev up.
I started to play wiggle the throttle cable around between the handlebars and where it disappears under the tank to see if I could free it. This seems to have made it worse.

What else I noticed is that the motor speed is sluggish to return down in speed when I stop wiggling it around or turn the handlebars back to straight.

I am guessing that the cable is gunked up with old grease which is holding back the cable from moving freely and this needs a good clean. I also thought that the problem could also be in the throttle grip.
Also to the best of my knowledge I did not screw with the throttle cable routing during the recent work on the carbs.

Any tips or tricks from the XJ masters of the forum would be tremendously appreciated.
I doubt I am the first to have this problem.
Thx
A

 

lube the cable with cable lube would be a good first step. they make a block that clamps over the cable and you squirt lube into the little hole and lube flows out of the other end. you can see them in this link
https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=cable lube tool

measure the cable to see if it is the correct size
routing is critical.

chacal listed this in his catalog
OEM original THROTTLE CABLE, with black curved plastic tube, adjuster nut, and thumb-wheel on the throttle end of the cable, for all 1983-1992 XJ900RK, RL, N/FN, and F models. Wire length = 38-1/2".

Nice looking Bike

 

thanks

 

I would replace the cable just due to age and not wanting to eventually have to ride home with a broken one.
I would also disassemble the right-hand switchgear and clean the throttle tube, switchgear housing, and handlebar, as well as re-lube with a dry graphite powder or a dry silicon spray-film.

I would also double-check for proper cable routing.

 

I had similar problems when I first brought my XJ home. As the throttle cable seemed tight, I attempted to loosen it at the grip end with the tensioner... but no matter what direction (tight or loose) I sent it in, it didn't seem to fix the problem. I called the PO and asked him what he thought. He said... "Yeah you're going to have to replace the cable you have there. The one that is on there is not a throttle cable. It is a brake cable from my Schwinn that I slid into the throttle cable sheath when it snapped a while back..."

 

Necessity is the mother of invention or inovation

 

Yeah - replace a 900cc superbike throttle cable with a bicycle brake cable. That´s not innovation, its desperation!!


I just removed the throttle cable this arvo and found it in pretty good condition. I´ve let some metho (degreaser) run through it and hung it dry. Will lub it up with some teflon spray and give it a go.
Just first observations:

• Looks like the original cable - no OEM 'bicycle' mods. Would even venture to say that it has never been removed from its routing.
• Seemed nice and loose in the sheath before degreasing step. Also the throttle rotated easily.

These points made me think that the spring tentioning on the carb may not have enough touque to pull the cable back properly. Dunno :-|

My next step is to get my hands on a long piece of fuel line and run the bike without the tank mounted to see what exactly is happening.
I am guessing that lifting the tank above the carbs somewhere, blocking the vacuum line (connecting to petcock), and setting the petcock on RES will allow my to run the engine like this?`Am I on the right track?

 

Aside from the length, it's the same type of cable. It's very much like how 6mm machine screw from a car is not functionally different from a 6mm machine screw off of a telescope, or a microwave oven, or a motorcycle.

We often send people to their local bike shop to have replacement cables made if they don't have a local motorcycle shop.

 

When you cleaned the carbs, did you break the rack? Did you remove the throttle plates?
I'm thinking about common issues that lead to the throttle shaft sticking.

 

No.
I left the rack in one piece.

 

Solved the problem.

I think I did something stupid (I am pretty sure in fact) when I was reassembling the bike after the carb work.
I cannot remember it but I must have stuck the throttle cable inbetween the frame tubes that run under the tank.
Only by setting up the tank remotely and running the engine and turning the handlebars did I see that the only way the throttle cable can routed with out this overrev problem is to run it along the right side of the frame under the tank.
Now it runs well. And the cable has been cleaned out and lubed again. Another renovation done.

Thanks for the advice guys...