Too much play in throttle

snoopy · December 23, 2012, 10:57:55 AM

I was tooling around late last night on my Magna, taking a friend and I to the movies, when on the way back I noticed that my throttle was acting up. When I would try to apply throttle suddenly (Had to pass the slower mall crowd) It felt like it was slipping, almost as if my gloves were slipping on the grip.

I noticed that it took play (about an inch) to engage the butterflies in the carburetors, but I was able to get the bike home safely, even having to start from stop lights. Is there an adjustment that may have just gotten out-of-whack, or does it sound like the throttle/handle bar assembly is busted?

Greg Cothern · December 23, 2012, 11:02:54 AM

Check to make sure the throttle cable holding bracket on the side of the carbs. Sounds like the screw may have fallen out.

snoopy · December 23, 2012, 09:33:52 PM

That's underneath that "fake" airbox?

TLRam1 · December 23, 2012, 10:42:52 PM

Yes, on the left side.

snoopy · January 24, 2013, 05:10:27 PM

Okay, The weather today was too nice for me to ingore my Magna any longer. I've checked it out, and don't think my issue is a loose screw [....

]. I took a photo from underneath the fake airbox, and it looks like the slack I'm feeling in the throttle is due to something in the handle or maybe the right-side switch assembly. Does this photo seem to indicate that?

I don't think the cable backed out of adjustment, but if that's possible, I can try tightening up those cable sleeve threads from the bottom cable. Any ideas?

hootmon · January 24, 2013, 06:13:18 PM

Adjustment in order, but if the lock nuts are tight, it my be time for some new cables... There is an adjustment on the handle as well

Greg Cothern · January 24, 2013, 06:15:42 PM

I agree with Hootmon...

snoopy · January 24, 2013, 06:28:12 PM

So I can back that cable sleeve as far back as it will go too see if it's enough?

hootmon · January 24, 2013, 09:28:48 PM

Quote from: snoopy on January 24, 2013, 06:28:12 PM
So I can back that cable sleeve as far back as it will go too see if it's enough?

Yes, BUT the question is, why did a steel cable stretch? Probably not a good sign...
The cables are not that much, and probably cheaper than a tow home because it broke!

snoopy · January 25, 2013, 05:40:57 AM

Thanks, replacement does sound like a good idea. I need to replace the left signal assembly anyways to pass inspection next month since the turn signal switch head broke off last year. Is there any chance that the problem could be something else besides replacing cables? I.E. should I add a right switch assembly along with cables and my left switch assembly?

Smoked U · January 25, 2013, 11:10:14 AM

Quote from: snoopy on January 25, 2013, 05:40:57 AM
Thanks, replacement does sound like a good idea. I need to replace the left signal assembly anyways to pass inspection next month since the turn signal switch head broke off last year. Is there any chance that the problem could be something else besides replacing cables? I.E. should I add a right switch assembly along with cables and my left switch assembly?

Do the simple stuff first. It really does pay off.

Check along the length of the cables to make sure that the braided section inside the assembly has not eaten its way though the outer jacket. If the cables are sound. use the adjusters at the carb linkage to remove the slack from the cables ( from your picture you have a lot of adjustment available). Test it. As stated above, there is some additional adjustment at your throttle grip as well.

It is possible for a braided wire to stretch a little over a long period of time, however, the slop I am seeing in your push pull cables is a lot more that stretching. Did you just do a carb job? You have to loosen these adjusters to get the carb bank free.

snoopy · January 25, 2013, 11:28:53 AM

Quote from: Smoked U on January 25, 2013, 11:10:14 AM
Do the simple stuff first. It really does pay off.
It is possible for a braided wire to stretch a little over a long period of time, however, the slop I am seeing in your push pull cables is a lot more that stretching. Did you just do a carb job? You have to loosen these adjusters to get the carb bank free.

No, I have not worked on the carbs recently. When I was out on the bike last time I noticed that the throttle was good at first, but then something "gave" when goosing it, so something broke or gave way. I'm going to go look at the handlebars and see where I can make adjustments on that end ... and I'll report back.

snoopy · January 25, 2013, 11:35:48 AM

Okay, there is about 45 degrees of "free play" in the throttle. I did not see anywhere where I could make adjustments.

lragan · January 25, 2013, 12:35:09 PM

Face it, Brandon, you need a new throttle cable. No question about it.

When you remove the old one, a failure analysis is in order. I would love to know just how the cable failed in a way that it "stretched" that far without coming apart.

snoopy · January 25, 2013, 01:22:18 PM

Yup, I'm planning on buying lots of goodies to get my Magna up and running for my Inspection next month. Left switch assembly, right switch assembly, A and B throttle cables, and while I'm at it, some sub air filters and a set of side panel grommets. I'm even thinking of getting myself a tool kit as a present.