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Oops! Screwed up...

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I bought a '97 DR650 a little while ago but haven't rode it much because of the shitty weather....it has the mid pipe and GSXR muffler...PO told me he drilled the slide and put a shim under the needle...it ran decent I guess. It needed a new air filter(had a oily stock one)so I put in a new K&N and went ahead and cut the air box....this is where the oops comes in...runs like crap now! Idles fine but falls on its face at mid throttle...I'm guessing I should get the DJ kit but I want to ride tomorrow!! Its finally going to hit the 50's here...any chance the local Suzuki dealer will have jets for the stock carb? Any suggestions until I get the kit? Thanks...

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How does it run at WOT?

It could be running lean now that you changed the filter type and cut the airbox, or it may be too rich in mid-throttle after shimming the needle.

It's a 3-step process to get the bike to run right:

1) get the fuelscrew set just rich of the RPM peak at a high idle. Then set the idle to the normal idle speed. (fuelscrew = between 1 turn open and 2 1/2 turns open). Change the Pilot Jet as needed to get the fuelscrew to be in the correct range.

2) Get the bike to make the best power at WOT. Use a Main Jet 1 size rich from the WOT peak power. If you can't tell the difference between two jets, use the richer one.

3) Shim the needle or change the needle to get the best throttle response (not necessarily the best power) between 1/4 throttle and WOT.

4) If you have a bog, you can do things to the Accelerator Pump to get rid of it, but let's save that for later.

I suppose you can try to duct-tape the airbox back together to richen the A/F mix up until you can take care of tuning the carb. :thumbsup:

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I bought a '97 DR650 a little while ago but haven't rode it much because of the shitty weather....it has the mid pipe and GSXR muffler...PO told me he drilled the slide and put a shim under the needle...it ran decent I guess. It needed a new air filter(had a oily stock one)so I put in a new K&N and went ahead and cut the air box....this is where the oops comes in...runs like crap now! Idles fine but falls on its face at mid throttle...I'm guessing I should get the DJ kit but I want to ride tomorrow!! Its finally going to hit the 50's here...any chance the local Suzuki dealer will have jets for the stock carb? Any suggestions until I get the kit? Thanks...

Once you mod the air box you have no choice but to buy the DynoJet kit. The massive increase in air flow from about 3/8 throttle up with the modded air box requires a needle with a much sharper taper than the mildly tapered stock needle. No amount of shimming will fix your issue. By doing so you will end up with rich parts of the throttle and lean parts of the throttle. The taper must match the in coming air flow potential to provide the correct AFR. So strangle your engine back to "as they come from the factory" or get the proper needle for the increased air flow of the modded air box. I vote for the latter.... you will too once you ride the bike with the air box open and the jetting correct. :thumbsup:

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Thanks, I will get the DJ kit for sure! Guess I'll strangle it for the weekend though so I can at least ride a little.

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Why not just close the box back up for the weekend? Like tape the cut peices back on the air box or somthing. Or tape some cardboard over the holes.

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just put the piece you cut out back into place and duct tape it. Problem solved until you get the DJ kit

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