Bonneville America Forums Forums Technical Forums General Tech Throttle Questions

Hi,

I picked up an America from ebay with only 3000 miles on it, registered 11 months ago.

The bike is in good conditions, but have just riden it for the first time apart, from a quick run after I passed my test a few weeks ago.

I have two questions regarding the throttle

On the bike I practiced and sat my test on (some nasty sports bike), the throttle would almost spring back to off, but on the America it does not appear to respond the same. It is not the cable sticking as when I turn the throttle it closes and reduces the acceleration.

The second one is that when deccelerating the noise from the exhaust is a "putt, putt" almost as if the engine is misfiring. It has short cut exhausts (if this makes any difference.

I am planning to take it to a local dealer to be checked out but want to know what to say before I get there.

Thanks
Jazz

Loosen the two bolts that hold the throttle control housing and slide it slightly down the bar. I'd bet it's binding a bit.

All these bikes putt-putt when stock. The carbs a set very lean from the factory. If you still have the air injection installed (shiny tubes right in front of the spark plugs), you should remove them with an AI removal kit. You also need to adjust your air mixture screws and balance the carbs.

Something else to check on your throttle, some people wedge a gumband between the grip and mount for a sort of 'poor mans' cruise control.
As for the exhaust noise while decelerating, get a set of proper aftermarket pipes and it will change to a nice 'crackle snap' sound that should be coming out of a high performance engine. Or, if you make sure the air injection system is removed (this kit works very well http://newbonneville.com/html/ai_removal_kit.html ) and adjust the idle mixture a little richer.

The throttle can also stick if the cables are too tight. There should be 1-2mm (about 1/16") play in the throttle. There's tension adjusters on each cable.

It can also get sticky if someone's used the wrong lubricant on the cables (eg: chain lube). If you're going to use any lube at all it should be a silicon based cable lube, however you shouldn't ever need to lube these cables. If someone's sprayed something down them you'll probably need new cables.

I have found usually the cable is not adjusted properly. You can adjust at the throttle side easily.
To add to the other suggestions, in addition to freeplay see if you can wiggle the throttle a tiny bit left and right also. If you can't, moving the control housing a little bit should free it up.
Welcome to the site!