the earlier stock grip tubes are all pot metal. the newer replacement ones are plastic grips ''grafted to' ? huh, pot metal teeth.

when all is said and done lubriplate works well for the inside tube, twist gear & chain area

https://www.lubriplate.com
Lubriplate Lubricants Company is a leading supplier of high quality, high performance synthetic and petroleum based lubricants to a wide range of industries. Products include; gear oils, compressor fluids, hydraulic oils, multi-purpose greases, NSF H-1 registered food machinery grade lubricants, environmentally responsible lubricants, specialty lubricants, spray lubricants and more.

Mine must be original, the tube around the bar is some type of gray pot metal. I've loosened the control housing and moved it inboard a bit, so I know there is no part of the twist grip part seized to the controls.

Luckily with the nice weather I'll be home to my Maine/main workshop in a week or so and get some heat on the subject! 🙂

Thanks for the ideas.

If you can get hold of some Kano Kroil, or Breakfree CLP, either will creep between and loosen up the rust. CLP is some awesome stuff, lubes and prevents future corrosion. Gun stores will have it.

heat it

Sounds like you're going about it the right way. PB Blaster is pretty good, but a mix of ATF and acetone is better (50/50). Either way, with penetrating oil time is your friend. You might accelerate things by heating the twist grip to spit sizzle temps, spraying both ends with the penetrating oil, and letting it cool. The cooling action might help draw the oil into the gap. But at the end of the day, patience is the key. Keep applying the oil daily and try to move the twist grip on the bar. Sooner or later it'll come loose...

This is very good information. As strange as it sounds, the 50/50 of ATF and acetone has been proven best. Google it if you need proof. However, Kroil, PB Blaster and the others mentioned are also very good. Light to moderate heating will speed things up.

Your corrosion issue is very common and easily preventable. You have an excellent example of galvanic corrosion between the chrome bar and the cast grip. The presence of water between the differing metals created a small battery, and the result is similar to battery post corrosion. After disassembly and cleaning, apply a generous portion of any type waterproof grease (white lithium, boat trailer wheel bearing, etc). Not only will your throttle be much smoother, but this problem will never reoccur.

UPDATE: Well after moving back to Maine from FL I finally got a chance to really get to it. I removed the handle bar from the upper triple clamp, stood it on end throttle up. Next I applied PB Blaster just enough to fill the little grove made between twist grip and handle bar. Then applied heat gun at 850F moving around the grip and up/down, until the PB began to boil. Removed heat let cool 30sec and repeated 2 more times. Then with a rag on the grip and small pliers with light torque the twist grip twisted and came OFF!
Hope to have her on the road by tomorrow, YEAH!
Thanks All
Edward :woohoo:

Wob's right
a cheap little squirt or dropper bottle from say TAP Plastics &&

Penetrating Oil
In a thread in the antique machinery forum, there was a discussion what to use to free up a part. Southbendmodel34 had mentioned a study in Machinist Workshop stating that Automatic transmission fluid and Acetone mixed was the best.
I just received a newsletter today from Tim Carter mentioning the same study. He had included the results of the test, which I thought interesting.

A study done by Machinist's Workshop magazine in their April 2007 issue looked at different penetrating oils to see which one did the best job of removing a rusted bolt by measuring the pounds of torque required to loosen the bolt once treated. If the study was scientifically accurate, it turns out a home brew works best!
Here's the summary of the test results:

Penetrating oil ..... Average load

None ...................... 516 pounds
WD-40 ................... 238 pounds
PB Blaster .............. 214 pounds
Liquid Wrench ...... 127 pounds
Kano Kroil ............. 106 pounds
ATF-Acetone mix ....... 53 pounds

http://www.practicalmachinist.com/vb/general/ot-penetrating-oil-196347/

http://www.jalopyjournal.com/forum/threads/penetrating-oil-showdown.350800/

In another life, I did a lot of offshore sailing. My problem there, as related to this thread is corrosion. Sailboat masts are (generally) made of aluminum and all of the fittings (expensive attachments) are made of brass, bronze, aluminum or stainless steel. All of the fasteners that hold these attachments to the aluminum mast are stainless (or, you'd better hope they are).

Salt water then gathers in the cracks and crannies and starts a galvanic process that produces a hard white cement-like layer (aluminum oxide). This layer, if left to its own devices will keep growing until it freezes the various components solid. As this stuff is almost impossible to dissolve, it is far better to prevent it than try to fix it. Prevention is best done with a product called Tef-Gel. This stuff , is a sticky white paste that is applied extremely sparingly to the fasteners as they are installed in the tapped holes on the mast. One treatment lasts, seemingly, forever. My current boat has been around the Pacific over the past nine years and I can remove any fitting with ease.

Darn fine stuff. I'll bet that a thin film spread on the handlebar, between the dis-similar metals, before installing the throttle assembly will solve this problem - for good.

In the USA, get it from any chandler (yachtie parts store) like West Marine or buy online from many sources.

If any of you purchase Tef-Gel, be sure it is that product and NOT Tuff-Gel, which is a sealant!

Many assemble these items using moly grease on the gears, cam, and chain; and, using most any common antiseize, including ones with 'copper' in the name, or, common silver Permatex (which DOES contain copper)....on the tube/bars interface.