Throttle completely stuck

[cvalliere]

This bike is kept in a clean garage. When the weather gets cold, or if I leave my bike sitting for a long period of time. The throttle can become completely stuck, I have lubed the cable with a MotionPro cable lube device multiple times over the last three years to try and fix this, I have lubed and greased the actual throttle tube around the handle bar after removing it and cleaning it as well (no rust). I have ensured that the bar end is not too tight. The cable play looks adequate. I've cleaned and lubed the one spring accessible from the left side of the bike right where it's attached to the throttle body. I suspect it could be the throttle bodies freezing up? Is this a thing and how would I go about fixing this?

It becomes operational and improves the longer the bike is running, this is why I feel like it is the throttle bodies. I'm on a 2006 model and I'll admit it hasn't received a lot of love over the last 5-6 years. I ride it maybe 3-4 times per year.

Grateful for any direction.

 

[Gary in NJ]

I very much doubt that it gets below freezing in your garage in Texas. Given the maintenance that you've done on the cable and throttle tube, I'd suspect corrosion where the throttle valve plate shaft go through the throttle bodies themselves - or most likely the TPS which sits on the same shaft at the opposite end of the throttle wheel. You can remove the TPS the next time you experience a frozen throttle to isolate the issue. If the throttle frees up with removal of the TPS the problem is solved with a simple part swap. If the issue persists, I would try to directly rotate the throttle wheel to see if the problem is the shaft itself. If it is the shaft, I recommend removing the throttle bodies and overhauling/cleaning the throttle body shaft.

 

[Motogiro]

Could be an issue with the throttle body linkage. Do not use WD40 on these parts. WD40 gums after a while. It's a great product for it's intended use but is not good for long term use lubrication on some applications.
The fact that it changes with warming might be an indicator of a gummy lubricant.

 

[cvalliere]

I very much doubt that it gets below freezing in your garage in Texas. Given the maintenance that you've done on the cable and throttle tube, I'd suspect corrosion where the throttle valve plate shaft go through the throttle bodies themselves - or most likely the TPS which sits on the same shaft at the opposite end of the throttle wheel. You can remove the TPS the next time you experience a frozen throttle to isolate the issue. If the throttle frees up with removal of the TPS the problem is solved with a simple part swap. If the issue persists, I would try to directly rotate the throttle wheel to see if the problem is the shaft itself. If it is the shaft, I recommend removing the throttle bodies and overhauling/cleaning the throttle body shaft.

Sorry I need to update my bio, I live in SLC now. It was 40 degrees over night last night, so not freezing, especially since it is stored in a garage.

Thank you for the troubleshooting steps. It seems I have myself a weekend project!

 

[cvalliere]

Could be an issue with the throttle body linkage. Do not use WD40 on these parts. WD40 gums after a while. It's a great product for it's intended use but is not good for long term use lubrication on some applications.
The fact that it changes with warming might be an indicator of a gummy lubricant.

Thanks! Do you have any specific suggestions on a more appropriate lube product for this job?

 

[Motogiro]

Thanks! Do you have any specific suggestions on a more appropriate lube product for this job?

There are a kazillion lubes out there. Light throttle cables are not the same as clutch cables that have lots off spring return and lever pull, so I would use a lighter lube on the throttle cables as well as other throttle control areas. I've never has a problem with silicone type lubricants in light lube applications. Silicone lubes have a much wider ambient temperature range and will work well in the cold.

 

[grahammarsden]

First thing I would suggest would be to detach the cables from the throttle end and from the throttle body linkage at the engine end and see whether the problem is with the grip, the cables or the actual bodies themselves.

Once you've isolated the cause, then you can work on a fix.

 

[cvalliere]

I’ve cleaned this mechanism as well as the one on the left side with some brake cleaner then applied some WD 40 branded white lithium grease to it. I also sprayed some lube up into the return cable hose and the throttle is actually moving now. Unplugging the TPS made no difference. My TPS resistance seems fine at 4.5 K ohms max resistance and 0.67 K ohms when throttle fully closed for the sweep/outleg resistance, those point to my TPS being okay.

I used this video to check the TPS with my voltmeter

 

[cvalliere]

I think my next best step is to remove the throttle cables completely and try and move the throttle pulley by hand, and I can also check the cables for movement issues when I have them detached. I tried moving the throttle body linkage by hand but it seemed very stiff with the cable attached.

 

[grcamna7]

I think my next best step is to remove the throttle cables completely and try and move the throttle pulley by hand, and I can also check the cables for movement issues when I have them detached. I tried moving the throttle body linkage by hand but it seemed very stiff with the cable attached.

Have you tried moving the throttle body linkage by hand with the cables detached ?

 

[cvalliere]

Have you tried moving the throttle body linkage by hand with the cables detached ?

There's not a great place to get leverage with my hand. I tried a little bit at the middle linkage pictured, but it was hard to budge.

 

[Gary in NJ]

Unplugging the TPS made no difference. My TPS resistance seems fine at 4.5 K ohms max resistance and 0.67 K ohms when throttle fully closed for the sweep/outleg resistance

I wasn’t suggesting unplugging the TPS, I was suggesting removing the TPS from the assembly. It is possible that the TPS is damaged and is restricting movement of the shaft.

Remove the throttle cable from the throttle wheel OR the TPS. Either step will reveal the next step.

 

[grahammarsden]

If the cables aren't moving freely through the tubes, you can try lubricating them, but I'd consider it more sensible to replace them as there could be wear on the inside that you can't see.

If they do move freely, reattach the cables to the throttle body pulley and you should then be able to move it by pulling on the ends that would normally attach to the throttle grip.

 

[cvalliere]

I wasn’t suggesting unplugging the TPS, I was suggesting removing the TPS from the assembly. It is possible that the TPS is damaged and is restricting movement of the shaft.

Remove the throttle cable from the throttle wheel OR the TPS. Either step will reveal the next step.

I wasn’t suggesting unplugging the TPS, I was suggesting removing the TPS from the assembly. It is possible that the TPS is damaged and is restricting movement of the shaft.

Remove the throttle cable from the throttle wheel OR the TPS. Either step will reveal the next step.

I removed both the TPS and the throttle cable from the throttle wheel, the shaft is still difficult to turn by hand - and the return closure is slow as molasses

 

[cvalliere]

Also I think I just pulled my throttle bodies right out of their boots (yes I loosened the boot clamps). It took a lot of force to pull the throttle bodies up. The black rubber is not attached to the throttle body.

Edit: pushed it back in the boots! Phew.

 

[TownsendsFJR1300]

All great posts above but...

I'd brake clean all that nastiness from the TB's, shaft that passes thru, springs, etc.
You don't want to push any of that crap into the area.

Loose the white grease till the TB shaft moves easily.
Liquid wrench or better yet PB Blaster will get into those shafts and TB's

Once loose, you can use the white grease but it's really not necessary.

Again, as posted above, disconnect cables at the left side of the engine and
then do your checking , narrowing down.

That cable plate should move EASILY, even by hand reaching thru the frame.


The return spring should work fine once all that craps out of there- Gotta get it all CLEAN, then lubed...

.

 

[cvalliere]

I brake cleaned it some more and I have some liquid wrench being delivered today.

I disconnected both the cables and the TPS and the cable plate does not move easily. I even used a pliers to manually turn it from the TPS side and it still takes more effort than it should.

I’m hoping the liquid wrench can help.

Is it safe to directly apply liquid wrench to the butterfly pivot points within the upper throttle body chambers?

 

[cvalliere]

OK, now that I’ve cleaned and used some penetrating oil and lubed where the shaft goes into the throttle bodies, both at the left side by the cable wheel and also in the middle, I can easily engage the throttle to open the butterfly valves. However, the problem that remains is that the return is extremely slow, I have to physically close the throttle to encourage the butterfly valves to close. Rather than the throttle snapping back quickly like it should.

Any suggestions?

Here’s a photo with the throttle completely open. Is this too much slack in the return cable?



Here’s a photo of the throttle completely closed

 

[TownsendsFJR1300]

Spray the Liquid Wrench on EVERY point, including inside the throttle bodies spraying at the shaft.
It sounds like some corrosion and crap built up. Once the fluid is in there it should loosen up.

You may have to spray it more and manually move it more back and forth but it should loosen up for you.
There was no mention of anyone tinkering in there before so I don't think it's more than that.

The bike may smoke a little once done, not an issue.

With both cables (pull and return) disconnected, will the TB plate close on it's own?
Does it move freely in both directions by hand?

Again with the cables disconnected, can you pull the "pull cable"(at the TB plate easily?
Both those cables should move freely. If they don't, lubing doesn't help, they may be frayed inside
(those cables rarely fray un-like the clutch cable).

Just need to narrow down EXACTLY what right now is not co-operating...

Keep at it and post back what you find after spraying more..

Also, there is a return spring for the TB assembly. I believe it's under that plate
(not sold separately, it's part of the TB assembly from Yamaha). Make sure both ends are intact. and working.
The FJR,s if you took one wind out of that spring it still closed the throttle but made the throttle much easier to turn.

IE, if that spring un-wound once / or is broke, that would definitly cause a none closing or slow throttle.
Above likely isn't the issue but THAT spring pulls the TB shaft closed..




.

 

[cvalliere]

I gave EVERY point an extra spray with the liquid wrench and worked it a bit. Then gave it another extra spray and let it sit. Including the shaft entry points inside the TB cylinder.

I’m happy to say that they are working MUCH smoother now. While not perfect they’re snapping back pretty good.

Thank you for all your expertise and help along the way. I’m hoping this does the trick for a while. I’ll report back if anything changes.