Jumpy throttle in gear

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Superhart1977
Posts: 5
Joined: Sun Apr 15, 2012 7:53 pm

Jumpy throttle in gear

Postby Superhart1977 » Sun May 27, 2012 7:54 pm

i have a with 2007 ex650 with 4000 miles on it. when i am in 3rd or 4th gear going 3000rpm or so, steady on the back roads. it seems that the rpm jumps 100rpm's and has a jolting ride. is this normal that the bike does this, its almost like a rough cruising rpm rather than a smooth riding rpm, its very jolty because of the fluctuation. i am not moving throttle while this is happening. any ideas? thanks
steigs84
Posts: 117
Joined: Thu Oct 02, 2008 2:17 am
Location: Fort Worth, TX

Re: Jumpy throttle in gear

Postby steigs84 » Tue May 29, 2012 2:32 pm

Your might want to check your Main Throttle Sensor, you can do this without pulling the throttle body by following the service manual. Please check all throttle free play adjustments before this.
I had a similar problem, I thought maybe carbon build up in the throttle bodies because I've experienced this similar problems working with car throttle bodies. As it turned out, the Main Throttle Sensor had a dead spot. I pulled the throttle body to clean it, I decided to check the MTS IAW the manual, (page 3-44/46) it would read 1.8 volts then zero then back to 2.1 volts as I open the throttle, a resistance check showed the same dead spot. You would think this would set the service code in the CPU, but there were no codes stored.
As of a few months ago, they don't sell the MTS separately you have to order the whole throttle body/$490 @dgy.com. I found a used throttle body on craigslist for $75 (I did check the resistance before I bought it). If it helps I have an '06 with 38,000 miles.
steigs84
Posts: 117
Joined: Thu Oct 02, 2008 2:17 am
Location: Fort Worth, TX

Re: Jumpy throttle in gear

Postby steigs84 » Thu May 31, 2012 11:01 pm

Can also be bad coil sticks, you might want to do a search on them in tech.

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