The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: ddebonis on October 26, 2013, 03:48:40 PM
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Hello!
So I've noticed my throttle is a little sticky when opened. It doesn't want to close on it's own. I opened the throttle body and it's well lubed. Doesn't seem to be any interference along the throttle cable. Owner's manual says DO NOT lube the cable. So... any ideas on how to get it to snap closed more easily?
Thanks!
Danny
P.S. I've got a handful other other issues I need help with. Keep an eye out for posts on carbs, timing, and rear wheel play. :)
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There are throttle return springs on each carb, check to see if they are still there .
Possible that one or more of the throttle cables is worn and binding up .
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Throttle tube around the handlebar could be dirty/gummy/sticky...
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Hello !
Also check the plastic tube under the tank where the cable from the handlebar split in two to get to the carbs. sometimes, the metal cable tensioner gets so rusty, it seize the cable passing into it.
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The throttle and choke springs and their linkages on my carburetors were pretty rusted. It may be worth cleaning up the pieces and possibly replacing the springs. Dave2
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When this happened to me, it was the lube on the gear that the throttle spins that had hardened.. If I were you I'd figure it out before riding too much more.. My case actually exacerbated some pavement surfing...
(As I went down, I had the clutch in, so when I let go of the clutch, the transmission re-engaged with the throttle stuck and the bike sorta slammed me into the road. Hello separated ribs!)
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The teeth on the throttle tube that has the rubber grip on it, and the gear inside the throttle housing wear out also and cause a binding throttle as well .
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Looks like in your profile pic you have stock mirrors, but since it is somewhat relevant I'll point out that bar end mirrors have a way of rubbing grips and adding friction to the throttle grip, especially when the rubber isn't cut squarely.
While you don't want to lube the cable, you DO want to lube the cable ends, both at the grip and at both carburetors.
You can perform a simple test to see if the throttle grip is causing the problem. Disconnect the cable up at the handlebars and pull on it. If the action is smooth, the suspect is at the top end. If not, you can disconnect the lower end and check the action at the carburetors. If they are smooth, it is most likely a worn cable.
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Thanks for all the advice.
Funny enough, Matt, I dropped my bike for the first time ever thing morning on the way to the garage. But because I hit a patch of sand when I was braking. Bike fell out from under me. Didn't realize what was happening until it was too late. I hope in the future I have the reflexes to release the front brake and avoid the fall.
The throttle body is fine. The springs look fine. I can examine the lever on the carbs to see if they are sticking, but I think it's the cable. I notices it's frayed and it must be getting caught in the tube.
Gonna look more closely on thursday. I'll give an update.
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If there's a frayed cable I would replace it stat. Pretty tough to make it anywhere when it lets go while you're on the road.
I recently replaced a throttle cable. I noticed it was about to give up the ghost when I took the left carb off to have the exhaust valve worked. Very easy replacement process, probably even without removing the carb.
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The cables can fray in the little splitter box as well, plus the box can crack or get gummed up. In my case it was mainly worn gears on the throttle tube and the matching cog that needed replacing. I did cut a donut from a thin teflon sheet (cheap cutting board from the kitchen) and fit it between the throttle grip and the switch block. It eliminates any sticktion at this point. It's a Ducati detail and a good idea that I stole.
Also I only use light oil on the handlebar inside the throttle tube instead of grease because the grease dries out and gums things up.
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I hit a patch of sand when I was braking. Bike fell out from under me. Didn't realize what was happening until it was too late. I hope in the future I have the reflexes to release the front brake and avoid the fall.
Haven't we all done that or come close. I think you have to be very quick to avoid a fall unless the speed is very low.
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Haven't we all done that or come close.
Good thing the R65 has those outriggers to catch the bike when it falls over. ::)
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Good news: I have fresh new throttle cables!
Bad news: Throttle still sticks. But I needed new cables anyway since they were fraying.
I'll take a closer look at the upper throttle assembly.
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Regarding MotoDeBonis post: about 10 years ago here, we had an epidemic of some animal disease affecting farm livestock. So when leaving the country (at the Channel Tunnel) vehicles had to drive slowly through a sheep-dip affair, a kind of trench full of disinfectant. I went through on my Kawasaki GT and touched the front brake when I came up on to the level. Down I went, instantly. Who would have imagined that disinfectant can be as slippery as oil?
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I've not had the chance to solve the sticky throttle, but I have a related issue.
The new cables seem to be settling in... They've become looser at the carbs (From 1mm to 3mm). I tightened them and will have to re-balance the carbs. I am running out of space on the right side carb to take up slack. I should be able to adjust the screw on 1-to-2 splitter to help eliminate slack.
1) Any idea on how long it takes new cables to settle and/or stretch out?
Secondly, is the throttle cable supposed to be secured to the frame at any point? The old one wasn't and I hear older BMW's have a rubber block with holes drilled out to secure cables.
This is their current path: From the carbs, the two cables meet at the splitter which sits on the engine and flops around a bit. Then the single throttle cable goes through the left side of the steering head (passing behind the steering lock) before taking a right turn towards the throttle grip.
2) Does that sound correct?
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Did you align the microscopically small line on the throttle tube with the mark on the upper gear before replacing the top cover?
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After you get the splitter reassembled, adjust the adjuster on the splitter before you adjust the two cables that go to the carbs .
You need to adjust the single cable until you have 1-2 mm of freeplay on the cable at the splitter .
There were no mounting or securing points on the throttle cables from the factory .
I've never had any cable stretch issues wth new cables .
The only remote possibility I can think of, is the plastic block or plug that the cables slide into inside the splitter .
Unless it's broken and the slots the cable ends fit into are the same depth, I don't know what else to look for there .
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Thanks. I'll redo the slack in that order.
Montmil, I did not see a line on the gear or throttle tube.
However, finally I did notice moderate wear on the gears. I had to remove a lot of grease first. There are some burrs, but hopefully after I remove those and add new grease it will be fixed.
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I de-burred and re-greased worm gear with Lucas Red and Tacky #2 (NLGI) ...and the throttle sticks more than before...
Any ideas?
And Montmil, I found the marks you talked about. Thanks.
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I de-burred and re-greased worm gear with Lucas Red and Tacky #2 (NLGI) ...and the throttle sticks more than before...
That's good grease you've used. Perfect for output spline lubricant but a tad heavy for the throttle. Maybe wipe off and leave just a wee bit or use something lighter like a Lubriplate white grease. Remember the old men's hair grease commercial? "Just a touch can do so much"