Serious throttle sticking when cold

Mean

Mean

Joined
Aug 27, 2006
Messages
125
Location
Northern VA
Only find it like this when it is cold. If I go out and try to turn the throttle, it is stuck tight and requires some effort to free it. After that, all is good. Sounds like a throttle plate problem that involves contraction as it cools off. I obviously have to look at the carbs, but any clue to what might be the cause before I go looking? I will lube the cables too but they seem OK. And the problem occurs even when I leave the bike on the centerstand with the handlebars straight which I felt eliminated a cable binding issue.

TIA
1991 ST (32K miles)
 
Never had this to occur on a motorcycle but have had on a GM throttle body engine. Cure was a large dose of Berryman B-12 and a soak time. Start and run at fast idle for a couple of minutes. Had to do it about every 25000 miles.
Jim
 
By cold, I mean it has sat during the day. I commute so I see the problem in the morning and when I leave work to go home. So even 100 degree heat is cold by this definition. And the bike has seen it's share of downpours this year as it has been parked outside this summer. But I am not sure why it would refreeze overnight or during the day if there has been no rain. I seriously thought the cable was going to snap this morning.

I am going to spray some cable lube in there as my first fix and see what that does.

Thanks,
G
 
I know that if you don't have any slack in the cables it will cause the throttle to 'drag' and not fully return by itself. You may want to make some adjustments to the cable at the throttle grip and see if this helps - make sure you have a little bit of freeplay
 
Had this problem in a cage before. A good cleaning with some carb or throttle body cleaner resolved it.
 
If it's an ST1100 I have a spare set of cables. Also, have you had the engine cover off lately? It could be a cable routing problem if you have. I know mine is extremely sensitive to cable routing. I have to mess with the cables a bit everytime I pull the engine cover.

Does it feel like it's sticking at the throttle grip or someplace else like the cables/carbs?
 
Sounds like the throttle plates are sticking in their bores. Get access to them and dose them with what ever cleaner you like. I use Berryman B12.
 
Hmmmm... I used to have a sticky throttle, lived with it for a long time. When I got my current bike I had to remove the cables and carbs to resolve a cooling system issue.

Reinstalling the throttle cable REALLY helped me understand the whole cable tension issue, and made me wish I had dug into my sticky throttle issue on my prior bike. IMHO its worth it to
mess around with it until adjusting the cable tension becomes a clear process. No reason to live with a sticky throttle.
 
Definitely the cable. I found it stuck a few times in which I thought I would need two hands to break it free. Instead, I turned it the other way. It barely moved but that broke it free every time. I will try cable lube first and see what that does.

G
 
Stall, stall, stall, SNAP! That is what happens when you put things off.

I was riding to work yesterday and the throttle stuck open for a moment. I forced it closed and I felt a slight click. From then on, lots of throttle free play in the grip but I could still ride it. The forward pulling cable is fine. But the return is gone. I rode home that night. It felt a little weird with all of the free play but I had no problems. I haven't pulled it apart yet but I think I will stop by the dealer right now and see if they have a cable. On the fiche, it appears to be the B cable. $25-$30. But will they have it in stock...

G
 
Defiitely sounds like a cable issue. If you don't have a cable lube device just get a sandwich bag and poke the cable through one bottom corner. You can wrap a rubber bad around the bag to seal against the cable housing and then pour some oil into the bag and elevate the bag to allow the oil to migrate down the inside of the cable housing. You can leave it there for a few minutes to make sure the oil passes through though it may drip inside on top of the engine a bit.

Dan
 
Sometimes lube is necessary if the cables have been exposed to moisture and corrosion has set in. Lubrication can stop the corrosion and restore the cables to operation. Never had any issues with gumming up cables though I only lube cables if they need it. Lubed them for years even on my desert bikes that are exposed to a whole lot of dust and dirt without a problem. A lot of the new cables have a teflon lined inner cable that does not require lubrication but the outer housing can rust and keep the cable from moving freely.
 
Cable B was replaced on Tuesday. A little tricky getting the barrel on the carb end but that is all. The old one was very rusty in the entire area where is snapped. Perhaps I should change the other too. The bike is 20 years old.

Thanks,
G
 
I always say - it can't hurt anything but your wallet to replace a part you suspect of possibly failing or causing problems.
 
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