How do I shorten the throttle cable?

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Earthman

New Member
Mar 24, 2009
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Pittsburgh, PA
Hi, I’m new to the Forum and was wondering if anyone knows how to shorten the throttle cable that comes with a 2-stroke engine kit? Mine is about a foot too long and I’d like to cut it and make it shorter, but it has a small nub on the end that connects to the throttle and I assume I need that. Any suggestions?

I’m installing an “80cc” engine on a 24” Huffy “mountain bike” frame and it’s a real tight fit. I’ve got the engine on, but I may have to change the intake manifold so I can turn the carburetor out from under the top tube, or rotate the carb a bit on the existing intake manifold (so it’s not quite vertical) so I can get the throttle cable attached to it. I’ll try the later first and see if the carb still works.

In any case, I’d like to shorten the cable. Any suggestions would help.

Thanks
 

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Cabinfever1977

New Member
Mar 23, 2009
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Upstate,NY
take the aircleaner off and just use the foam part or run carb off the side.
just loop the throttle cable with the other cables on handlebars and tie together.or use a short brake cable with 2 nubs"im not sure if there the same'.
 

eDJ

Member
Jul 8, 2008
530
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Wayne National Forest
welcome to the Forum Earthman :)

It may be easier for right now to just route the cable the longest way you can so it
bows out in front of the bike and back to the throttle grip. You can get it
up and running and test everything this way without modifying it while it may be under some
warrenty terms with some vender.

A dremel tool with a fine adbrasive cutting wheel works well on cutting those stranded cables.

Cutting the lug off the carb end may cause the cable to roll up into the outer housing. No
worry if it happens as it can be delt with later. Now route your cable to the carb where you want it and remember to turn your handlebars hard to the left and right to see if you have
enough slack. (do this before cutting the housing) Measure twice and cut once. Just pull the outer housing out from the throttle grip so that when you cut it you won't be cutting the inner cable too .To cut where you have marked the housing, take a thin knife and cut thru the vinyl outer housing. Then take a pair of diagonal cutter pliers and ease them into the cut and squeeze. You'll be cutting one of
the windings that makes the housing structure. Have a nail that will fit into the housing handy to insert and size the opening. (so it's good and open) A sandpaper fingernail file will work good to
dress the opening and remove any burrs.

You'll likely have to pull the housing down from the throttle grip now and pull the cable out of
the spring loaded handle grip reel. Have a small modelers clamp ready now and when you get
enough cable out to come thru the end you just cut put the clamp on it and
shove the housing back into the throttle housing tight. You'll have nearly the extra foot
of moving cable exposed now at the carb end of the cable. (where you cut the outer foot of
housing off)

You'll need to cut the same amount of cable off to match the housing you cut off.

At this point you'll have to form a lug on the end of the cable like the one you cut off. It will have to be the same so it fits into the carb's throttle slide and not come off. You may find some of these
at a bicycle shop. These clamp on with a pair of pliers to squeeze them onto the cable.
"red" locktite would help hold it secure and dependable. You'll only need a drop and this is where
it may be a good idea to take it somewhere they have the materials to fit the lug onto the end of
the cable for you for a few bucks. If the new lug is larger than the original (make sure you keep
the original to compare it to) you'll have to sand it down by hand and make it fit properly. But once
you get it done like this you'll probably have a job out of it that you'll be satisfied with.

I would strongly suggest you fit it up first so you'll understand how it works if this stuff is all new to you.

But if I were doing it, this is how I'd go about it. Those small modeling knock off's of the Dremel
tool can be bought for less than $10 now and come with many cutting and grinding wheels and bits.

Some people mark the moving cable where they want to cut it with an ink marking pen and then put some soldering flux on the cable. Then take a small torch or soldering iron and heat it and melt some solder into the cable. When it cools they cut thru that. The solder serves to bind the strands of wire
in the lead solder so it won't fray. This is an old trick and works well.

Good luck and let us know how it works out.
 
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Earthman

New Member
Mar 24, 2009
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Pittsburgh, PA
Thanks! I will assemble everything before modifying the cable as eDJ suggests - good idea. After reading all the advice, I thought of another approach that I may try. I may have or can get some brass tubing with the right size ID & OD that I can solder on to the end of the cable. There shouldn't much force on it so this may work. Thanks again. I'll post another reply once I figure out what works.
 

2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
Thanks! I will assemble everything before modifying the cable as eDJ suggests - good idea. After reading all the advice, I thought of another approach that I may try. I may have or can get some brass tubing with the right size ID & OD that I can solder on to the end of the cable. There shouldn't much force on it so this may work. Thanks again. I'll post another reply once I figure out what works.
Welcome to the forum and you're on the right track as far as using brass tubing (hobby shop item) for the carb end of the throttle cable. A couple of hints here: Use a good grade of solder, preferably 95/5 and solder flux. (There is absolutely no reason to use 'silver solder' which requires much more heat and in fact, because of the excess heat can weaken the end of the cable) The best flux I've used is called No-Corrode. Clean the end of the cable with a degreaser such as Brake-Clean or any good grease cutting solvent. Also clean the brass tubing, 1/16" I.D. is what you should be using. Slide the pre-cut tubing onto the clean end of the cable and lay your soldering iron, (gun) tip on the tubing and heat it until the solder 'wicks' into it when applied to the end of the tubing. Allow to cool for a few seconds before moving the cable and you're done. I usually clean off any residual flux, use the same solvent you used to clean the cable.
As for the carb position. A small deviation from level is okay but don't go much over 10 to 12 degrees. This should give you enough to get the cable clearance you're after. Just keep in mind there is a float in the carb bowl that needs to be close to level to function correctly. Other options are a custom intake manifold that will move the carb to where you need it. Check some of the previous threads here for ideas on those.
Hope this helps. Send us pictures when you're finished. There are some very nice 24" bikes and they look good when done right. Good luck, have fun.
Tom
 

rfriesen

New Member
Aug 3, 2009
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Omaha, NE
I'm a little confused by the part about the copper tubing and the carb. What's going on with that again? Do you have any pictures? I'm looking to shorten all of my cables they're all too long.
 

rfriesen

New Member
Aug 3, 2009
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Omaha, NE
Hey Norm. I went to Norm's 2 stroke Repair Center. Is that what you ment? I didn't find anything there on shortening cables other than this one about throttle cables. What am I missing?
 

Norman

LORD VADER Moderator
Jan 16, 2008
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pampa texas
I did a short video on the throttle cable shortening not the best. I also did one on making the big ends by using a home made mold to pour your own ends Ilikeabikea hasn't put that one on here yet. I think there is some photo's but then again you will have to go find them I know that can be a pain but some info there you might be able to use.
You can look at my posts and find more info on the cable ends but you have to look and read through them most are on the second page or third page.
Norman
 

Earthman

New Member
Mar 24, 2009
82
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0
Pittsburgh, PA
I don't have photos. See attached drawing.

If you are shortening a cable assembly, you have to shorten the cable and the sheath the same amount.

First figure out how much you want to shorten the cable assembly by. This is "A" in the drawing. To measure "B," which is the total length of unsheathed cable, pull the end of the cable you are going to cut all the way out until the other cable stop hits the sheath, then measure the exposed length of cable to the end of the stop you want to cut off. Do Steps 1 & 2 on the drawing, then put the cable back into the sheath, pull it all the way out until the other cable stop hits the sheath again, then measure "B" from the cut end of the sheath to the point on the cable where you are going to have to cut the cable. Do steps 3 thru 5. When you are done, you will have cut the cable and the sheath the same amount ending up with a shorter cable assembly with the correct amount of exposed cable.

Measure twice and cut once, or you'll be sorry.
 

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rfriesen

New Member
Aug 3, 2009
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Omaha, NE
Thanks Earthman. Though Norman's video is greatly appreciated I couldn't really see what he was doing. I have the Benzo solder that I get at home depot. Can I use that or do I need something else?
 

Earthman

New Member
Mar 24, 2009
82
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Pittsburgh, PA
If Benzo solder's for pipes, you can use it, but you will have to find some rosin flux to help clean the joint. Don't use acid-based flux like you would on pipes. The acid will corrode the cable. You would be better off buying some rosin-core solder from Radio Shack. Also, don't use a torch to heat the joint. Use a soldering iron (electric or butane with a soldering tip).
 
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