Sticking Throttle Body slides

[TAlber8]

74 TX650 that sat for many many years.

one slide was completely stuck. After soaking and a little heat it loosened up and was good. Two weeks later its sticking again. Very noticable how slow it is to close.

Any ideas? dissambly will be a PITA since i'll most likely have to drill out those screws on the slide

 

[jim540]

If you have a small butane torch like you can get from Harbor Freight for $10.00 you can apply heat directly to the metal close to the screws. It's amazing what a little heat does for getting things apart.

 

[TAlber8]

Yeah... Was hoping to avoid removing. Looks like I'm not gonna be lucky

 

[gggGary]

That's why god invented impact tools. The slide doesn't have any screws are you talking about the carb cover screws? Use no heat on those, the diaphragm is RIGHT there. You need to remove and overhaul those carbs anyways. Both those slides should come out and get cleaned till they are spotless. No harsh chemicals anywhere near the diaphragms.

 

[TAlber8]

Slide is the wrong word, I mean the butterfly plate in the throttle body. Therest I already rebuilt and seems good to go. This was too but is sticking again (without use, they are still off the bike)

 

[XSLeo]

When you get the screws out of the top covers, take them to the hard ware store and replace with Allen Head screws.
I was just reading a thread about sticky slides and slides turning in the diaphram. As varnish builds up in the slide bore and on the slide you might not see the buildup but you can feel it with your finger nail. Carefully clean the bore and slide till any rough spots can't be felt.
No harsh cleaners and no coarse scrubbers or sand paper. This will take off metal off the slide and out of the bore, creating to much clearnce and then your carbs are just pretty paper weights.
Leo

 

[XSLeo]

On the butterflies, loosen the screws, with the idle speed screw backed out so it won't touch the stop on the throttle, open the throttle and let it snap shut. This will center the throttle plates in the bore. Now tighten the screws.
Here is a good place ti use JIS screwdrivers. American phillipshead screws are differnt than the Japanese Industrial Standards phillipshead screws. Useing American screwdrivers in JIS screws strips them out.
Often when the plates are off center they stick.
Leo

 

[gggGary]

Ah OK that makes more sense. yeah still an impact tool to start them loose. You MUST use a JIS #2 bit NOT a regular #2 bit here. Cut a piece of wood to back up the throttle shaft from inside the carb. The only reason to remove the butterflys is to replace the shaft seals. Otherwise pb blaster or the like then I like spray grease here, probably white lithium spray grease because it is a very light grease. Or even garage door spray lube or tri lube. The solvent lets the lube penetrate between the shaft and body. Really on carbs this old shaft seals are about a "must do" anyways.

 

[jim540]

On the throttle plate screws I carefully ground the back side of the screws off with a Dremel Tool. Mine were slightly peened on the back side, I guess they did that to lock them in place. I ordered new screws from Mike's. Replaced the throttle shaft seals when I was able to get the screws out and remove the shafts.