Throttle stuck...

Just wondering if anyone had any ideas on why my throttle got stuck. I just picked up this bike and it is kinda annoying to have this gremlin floating around... All I can say about what happened is that I was going down the highway and eased up on the throttle. Bike kept at the same speed. Then I hit the clutch to see what was going on and the bike near redlined. The throttle handle seemed to be in the idle spot. I snapped the throttle a few times and it didn't do anything. Ten minutes later it went back to normal, though the idle rpm went to 1800 or so rpms. It still has a higher rpm at idle after warming up. No clue as to what happened. I did not mess with anything. I lubed the throttle lines a few days ago and that is it. I think the lines are routed the right way, They go outside of the forks right? I did have the forks off to change the oil in them, but did not pay attention to where they were, but put them on the outside of the forks.

98 vfr...

 

HONDA service manuals are GREAT help when routing wires, hoses, cables, etc. with very clear line drawings to follow.

Make sure the rubber handgip isn't rubbing against the switches.

 

Not sure what caused it. It was like the throttle cables went where they were supposed to go, and the engine decided to go faster.... Could there be anything with some sort of butterfly valve in the throttle bodies? Everything looks like they are routed properly.

 

I had the same problem...disconnect every thing...check the routing and check especially the return cable adjustment on the carb bodies..this is where my problem lay...

Likw squirell said..Check also that your rubber handgrip isnt affecting the return cable by rubbing against the collar of the handle bar.. many times its as simple as this.

If your cables haven't been lubed in a while, now would be a good time.

 

The handle grip is not doing anything.... functions as normal. twists as normal. returns to no throttle, but it still kept revving... cables were lubed last week. The only thing it could be I guess would be a throttle body thing, since the throttle handle twists back to idle, but I don't see how that would be possible. Never had something get stuck, have had the cable break on other bikes. It is just odd now that the rpms at idle are now higher. Going to take the air filter off and see if there is anything stuck inside and check the return spring on the throttle, though I cannot imagine that would affect anything considering the grip goes to zero throttle.

 

You need to get this straightened out before it costs your life. Not kidding.

Here is what you do.
With the motorcycle running and on the center stand turn the handlebars all the way in each direction and watch the throttle cables.
Make sure they do not get stretched tight at any time. The cables should be in back of the front forks.
They should be loose at all times. If the cable is broken inside the housing they could get hung up. take the screws out of the handlebar switch.throttl housing and look inside for a broken cable on the pull side and the push side.

Also look carefully where the cables attach at the carbs, and with the engine off make sure the throttle snaps back and does not rub on any thing in the attachment at the carb.
Make sure the barrel in the carb throttle device is positioned correctly. Make sure there is not too much play in the cables.

Sounds like when you worked on the forks you got one or both cables between the front forks.

 

Both cables go around the front fork. Both cables are still firmly attached to the throttle body and the grip. Nothing rubs. Nothing stretches. They are adjusted to just barely tight. Minimal slack. I will check to see if one is broken... I would imagine that if the pull side broke it wouldn't work at all. What is the point of two lines anyways??? My last bike only had one and it broke. I guess now it is just two parts that can cause a headache now. I did, however, tighten the nuts that hold the cables to the handlebar. I will loosed those guys up.

It is kinda nice to have cruise control, I just wouldn't mind to be able to shut it off. I guess it could cause a problem, but that is why there is a kill switch right there and always got the clutch ready to go. ;p

 

I have checked everything. It is like the Toyota problem I guess. Everything seems fine. I will take the tank off and check the idle screw and the rest of that stuff when it stops raining. Gloomy doomy Ohio weather.

 

So I adjusted the idle out and in the process of looking at the throttle parts under the tank lost one of those hollow tubes that go in the top of the tank bolts... into the motor section, and it did not fall out the other side. Great... Could it be an issue with the warm up circuit? Nothing seems to be out of sorts. Maybe this is the reason why my last bike I bought new. I don't like looking for gremlins and the idle is still rough.

 

"will loosed those guys up." Will loosen those guys up.

Anyway most motorcycles used to only have ONE throttle cable.
It all changed in the 1970's?
Some ones throttle stuck open, so the person sued a motorcycle manufacturer and now all motorcycles have two cables AND a return spring.
It used to be ONE cable and a return spring and some had two return springs.

Depending on a kill switch to get you out of trouble is dangerous thinking,
If the cruise control is causing the problem better get rid of it or get a different brand.

Motorcycles did not used to have kill switches either until the 1970's.
Probably what happened was there was a motorcycle accident and people at the scene of the accident heard the motorcycle screaming away
and had no idea how to turn it off so naturally they would look at the motorcycle controls to find the switch.

 

Good suggestion, Squirrelman.
That is a common mistake.
Making the grip too tight against the handlebar
and then the grip friction against the end of the handlebar stops or drags.

 

You said the cables had minimal slack, right??

One common cause of problems with throttle cables is not enough slack, so try using the cable adjustment up at the grip or down at the throttles to adjust looser.

Throttle twist grip needs 2-3 mm freeplay at least.

 

PO put some foamy grips on it. Unfortunately, the throttle side is too short. The upside is that it does not touch the control box. When it happened it was weird. The throttle did return to zero, but it kept going. There is no cruise control on it, it was a joke for the odd throttle activity to be the cruise!

I have ridden the bike about 500 miles since I have gotten it... Great White North prevented riding for long periods until last week. Also had to get an inspection. This single incident has been the only snafu with it.

I did adjust the throttle cables for a little more slack and loosened up the nuts on the bottom of the cables that come out of the control box.

Thanks for the suggestions, I will give it a shot later tonight after class and go for a ride.

Now I would just like to find someone in the Ohio/Western PA area that wouldn't mind going over it that has some experience with these.

 

I was showing a guy how to ride my Katana last weekend, and while he was out practicing in the parking lot, the engine started revving high without him touching the throttle. I couldn't figure out why the thing kept revving. I took it out and noticed that if I did left-hand circles, the engine speed would drop. If I did right-hand circles, it would rev pretty high. Initially I thought maybe it was a carburetor problem, but it seemed strange that it would happen so suddenly.

After playing around some more, I finally noticed it wasn't the lean, but rather turning the handlebars left/right that was causing it, which pointed at a cable issue. Sure enough, what had happened was when he was backing off the throttle, he hadn't been just letting the throttle spring pull it back to zero, he had actually twisted the throttle grip backwards (twisting upwards from the rider perspective) hard enough to spin the whole mechanism on the bar, which took too much slack out of the throttle cable, causing it to actually pull the throttle open when turning right.

So, just an additional thing to check. Make sure the throttle control is mounted on the handlebar properly

 

Agreed and this happened to me as well with my zx11

 

My cousin thought it was probably one of the butterflies in the throttle body, possibly because the bike has sat most of its life. I put more miles on it last week than the last owner did in several years. I am going to drop in a K&N filter really soon and am going to spray some cleaner in it. It was binding a bit on turning and since I loosened everything up seems ok.

 

If a K&N type filter was OVER TIGHTENED it could cause the throttle body to become out of round and a butterfly valve could get stuck.
That is a possibility. But it that was the case it would stay stuck open.

I still feel it is improper throttle cable routing or hanging up on some little thing. 90% of the time this is the cause.
Wish we had some photo.

 

use a non oil lubricant for the cable. this way it doesn't entice dirt and grime to get into the housing a cause you undue strife.

 

Cables are in front of the right fork and goes to throttle body... I use a dry teflon spray from lowes for cables and chain. I have put almost a thousand miles on it since I loosened up the cables and put a little slack and nothing so far. I think a butterfly got stuck. Cables were not hung up as I was going in a straight line so the tightness from turning wouldn't have been an issue.