throttle response changes when engine pushed to limit

I noticed that when I train to wheelie in first , after a few tries the throttle becomes slightly less responsive as the engine gets hot and it seems harder to get the wheel up when revving up the engine. The same phenomenon happens when I ride hard on fast trails . I must say I never ride with a full tank and I was close to reserve the one time I noticed a real lack of response after a few wheelie attempts.

But the throttle response seems best when the bike is used on the road (for its regular use) and not too hot. I guess this can be said of all bikes when they get too hot. I just want to make sure my jetting is not too lean and needs to be fine tuned (the stuff in the exhaust is brown not very greasy) I believe it is stock, everything else is stock.

But now that I think of it this engine is "kind of slow" to react to a progressive acceleration compared to my previous bike (YZ 250 2strokes).

I sometimes would like a meaner engine.

What bike are you riding? What carb does it have? CV carbs are super slow to respond by design. Swapping for a flat slide carb with an accelerator pump will make a huge difference on response. Even with a CV carb, dialing in the jetting and fiddling with different stiffness springs can make a big improvement, but will never match a good flat slide pumper carb (like say an FCR).

I ride a stock DR 650 SE , thought it was obvious...

The dynojet kit with an aftermarket muffler does make a difference, not heaps but worth doing.

More responsive, and a little more power.

:ride:

I ride a stock DR 650 SE , thought it was obvious...

Perhaps I'm slow, but it wasn't obvious to me as this section is for all DR's. Anyway, its almost certain that your stock carb is too lean. I'd start by trying incrementally richer main jets to see how that goes and turn the fuel screw out a quarter turn. The dynojet kits are usually pretty good and often include a softer slide spring which will help throttle response.

Alternatively, if you are feeling ambitious you could adapt an FCR to the bike had dial it in. I don't know how much work it is to fit them to the 650's but it would give the best possible throttle response.

best of luck

Thanks for the replies. I meant I thought it was obvious I was talking about the 650 given my problems to wheelie and the better engine's behaviour on the road . I don't think the stock 350 needs to be tuned up much like the 650.

I've noticed this after cruising at higher speeds for extended periods of time. Throttle response takes a noticable dive.

Perhaps the carb doesn't vent well? Might try doing T-vents and see if that helps any. I can't think of why it would get worse after riding for a bit. I guess a fuel restriction might do that - also check that the tank is venting and fuel flow to the carb is good and float level is corrrect.

good luck

Thanks for the replies. I hear the DR at least US model is lean out of the factory. How do I know if my bike runs too lean ? Besides reading the plug, which I can't even locate on this bike.

The dealer explained to me that there used to be a throttle stop (Swiss requirement) which he removes for customers, apart from that I think the jetting is stock.

Thanks for the replies. I hear the DR at least US model is lean out of the factory. How do I know if my bike runs too lean ? Besides reading the plug, which I can't even locate on this bike.

The dealer explained to me that there used to be a throttle stop (Swiss requirement) which he removes for customers, apart from that I think the jetting is stock.

"Besides reading the plug, which I can't even locate on this bike. "

I highly recommend you pick up a service manual for this bike and do some studying before diving into any repairs. It would present a great opportunity for you to learn about the workings of your bike. :thumbsup:

I have got a manual but it's not the Suzuki manual apparently. Still looking for that one in downloadable format. As far as the plug is concerned, I took a look the other day in the garage and I couldn't see it. I see in my little

user manual that it is actually screwed on the left side, not sticking out and on top like on a 2 stroke .

Create an account or sign in to comment

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

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now