Jump to content
Sign in to follow this  

bucking bronco in low gears... what the?

Recommended Posts

How smooth do your DR's run in 1st and 2nd gears at a constant low throttle (say 1/4)? In this range my bike bucks like a bitch, give it a tiny bit less throttle it drops right back, give it a tad more and it lunges forward. In the higher gears in this same throttle range it runs fine with no surging or rodeo type tendancies.

Share this post


Link to post
Share on other sites
How smooth do your DR's run in 1st and 2nd gears at a constant low throttle (say 1/4)? In this range my bike bucks like a bitch, give it a tiny bit less throttle it drops right back, give it a tad more and it lunges forward. In the higher gears in this same throttle range it runs fine with no surging or rodeo type tendancies.

It is a natural occurence on a big 4 stroke with a CV carb. You can't thump your thumper with the stock BST. To have your thumper run like a thumper you need a mechanically controlled slide carb like the FCR-MX or the TM40. 👍

Share this post


Link to post
Share on other sites
It is a natural occurence on a big 4 stroke with a CV carb. You can't thump your thumper with the stock BST. To have your thumper run like a thumper you need a mechanically controlled slide carb like the FCR-MX or the TM40. 👍

I can't help but think maybe your bikes are running a little different in the US, could be the air density or something but mine isn't too bad. If I let it idle and then crack the throttle it'll be rough for a brief moment but if I just slip the clutch a little or just wind it on a little slower to say 2000-2500rpm I can then crack it right open and its fairly smooth. I'm running the stock carb

Even the 07 XT660 is no better and thats fuel injected :worthy:

edit: the fuel you use also plays a big part, use the highest octane fuel you can get your hands on since the DR is a big single low revver it makes more logical sense to use a slower burning fuel. It helps to smooth the delivery out by 'pushing' the piston with a little less force but for longer, rather than 'shoving' it down abruptly by burning very quickly

Share this post


Link to post
Share on other sites

Simple, just ride WOT or none at all !well that seams to be my riding style.

The engine will run smoother at certain loads Vs throttle position, so as you load the engine up in the higher gears at the same revs the motor will preform entirly different than in 1st or 2nd. There are some simple things to do to smooth out the ride.

1. Change your riding style to suit the bike, dont let the revs drop to below 2500rpm at slow speeds, wind up the idle to reduce the hesitation these bikes suffer off idle.

2. Change the gearing, I may get some flack from this one but IMO the taller the gearing the smoother the ride will be, especially in the lower speeds, this suits the engine as its a slower reving engine with bulk torque down low that can handle tall gears and being loaded up.

3. Check out your jets, air box, pipe and gearing, just so you know what you have, as altering any of these from stock will produce more power 👍 but reduce rideability. Some combinations dont work well together. The question is, just how much power do you want Vs how smooth do you want the ride.

Share this post


Link to post
Share on other sites

yeah i thought it might be the CV carb causing it. as far as i know the carb is set up fine, i've had the bloody carb out, cleaned jetted and inspected enough times and finally settled on this config. my chain was totally cactus though and i replaced it yesterday as well as gearing it up to 15/41 (from 14/42). haven't ridden it yet to test out the difference. riding it to work this morning so will see how it goes in the heavy traffic 👍

Share this post


Link to post
Share on other sites

well a lot of the grin factor is gone with this gearing combination. it just doesn't have that ball tearing acceleration when you crack the throttle any more. on the plus side it's a hell of a lot smoother down low which makes it more manageable for city commuting. it also cruises now perfectly at 60km/h in 3rd gear whereas before 60km/h was in between gears a bit. can't wait for the w/e to open it right up in the hills and see the top-end difference.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...