July 29, 2015 at 12:21 pm #9341
Rank: 80cc Rider
Hi there, this is my first post on here.
I have a quick question regarding my DR650. I think it has a pumper carb on it, which I thought was meant to cure the hesitation at low revs. Problem is, when I crack the throttle open at low revs, it coughs, splutters and then pulls smoothly after that.
I have attached a few photos of the carb. Could anyone identify it?
In the one with my finger, am I pointing to the idle jet screw? I was wondering what the stock setting for that screw is?
Basically I’m at a loss and have no experience with these carbs. Any suggestions greatly appreciated.
Attachments:July 29, 2015 at 2:22 pm #9345
Rank: 1200cc Rider
- Bike: Suzuki DR650 ADV
First off welcome.
The shape of the carb looks like a flatslide carb, its definately not the stock carb so it could be a Mikuni TM40 which is a common upgrade for the DR.
I’m not familiar with that carb but the screw you are pointing to is where I would expect the fuel adjustment screw to be based on other carbs.
It sounds like either carb needs a clean, or the idle fuel mixture isn’t correct. If the mixture isn’t correct that could be due to where the adjuster screw is set, or due to the idle jet not being the correct size.
Have you established how many turns from fully in the screw is currently set at? I would expect it to be be in the 2-2.5 turns range.
Have a look at this thread too for some basic understanding of which carb parts effect what throttle openings.
carb tuningJuly 29, 2015 at 11:59 pm #9351
Rank: 50cc Rider
- Bike: DR650
Hey brother. Open the throttle very slowly from idle. If it still bogs then adjust your pilot air screw. Google is your friend here. If it only bogs when opened relatively quickly it could be too rich too soon on the pumper. Check this adjustment. The general rule is adjust to the thickness of a icecream stick. Adjust test adjust test adjust test. PM me if you need some help.
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