Jump to content
Sign in to follow this  

DR350se barely runs

Recommended Posts

Ok, just barely got my DR going again and now it is not running well. It idles fine, but stumbles and runs poorly just off idle, runs somewhat Ok around 1/3 throttle, and completely cuts out above 1/2 throttle. I've been through the carb several times, all the jets and passages are clean, the diaphram is ok, and the fuel float bowl level is ok. I put a timing light on it and I definitely have spark all the time, but I am unsure about how to check spark timing and advance, is it possible this is a spark/timing issue? Anyone else have suggestions, I am at my wits end.

Share this post


Link to post
Share on other sites

I know its a shot in the dark but how about the screen on top of the pet [@#$%&*!] valve. I guess the air filter is clean. My DR650 also has a backfire screen between the airbox and the carb. How old is the gas that your burning? Good Luck man, I know how it is to chase a ghost. :cry: P.S. Try some marvel mystery oil in your gas.

Share this post


Link to post
Share on other sites

Yes the screen on the petcock is clean, as is the air filter, in fact, I recently replaced the stock vaccuum operated fuel petcock with a high-quality Pingle fuel valve and I have excellent flow of new fuel from the tank to the carb. I also failed to say that the engine will die under load, for example cruising down the road at 1/3 throttle engine will die when starting up a hill, even if I don't change throttle angle.

Share this post


Link to post
Share on other sites

Maybe its electrical. I dont know what kind of spark advance system the dr has, it also could be the plug wire itself or the coil. Run the motor in as dark of place as possible and look for shorts

Share this post


Link to post
Share on other sites

A good rule of thumb to always check is , what did you change last, before it started running bad.

For you it sounds like this may have been your petcock. Your previous petcock is vacuum operated, it draws this vacuum from the intake manifold., which means that there is a fitting (read:hole) in your intake manifold. If you have not plugged this hole, then you have created a serious intake leak. But if this is the case, I would be surprised that it runs at all.

Hope i did not insult. Just trying to brainstorm for youu and this was not mentioned.

Drew

Share this post


Link to post
Share on other sites

I'm not insulted, but yes I did plug the vaccuum port on the carb for the vaccuum petcock. I think I'm going to check the carb again, perhaps I've just missed something. thanks to all who have tried to help.

Share this post


Link to post
Share on other sites

I have a 2001 dr650 that is having similar problems. It started as a quick and violent miss when really getting on it, especially if I was going a little slow for the gear. It seems to be getting worse,yesterday riding it in 3,4 or 5 at a constant speed the bike would miss and recover. It seems to run strong except the occasional burp. Nothing on the bike has been touched lately except I installed new plugs. I could only get a champion not the NGK or Denso spec'd (OK I didn't try hard enough) so I put them in. I am waiting on NGK's which should be here today. The spark seemed weak thru the champion's, I only saved one of the old Denso's that were in it but the spark looked better thru that. I did run it in the dark and didn't see anything. Hopefully the plugs will straigten it out.

Tom

2001 DR 650

Supertrapp

custom mt bike rack

Share this post


Link to post
Share on other sites

It turned out to be the plugs (see my above post) :cry:. Nice to have throttle back!

Tom

2001 DR 650

Supertrapp w/9 discs/DJ 170/ K&N

custom mt bike rack

NGK cr10e plugs

Share this post


Link to post
Share on other sites

I like the "R" resistors as well b/c you dodn't have to worry about gapping them right. Or do you not even have to gap the regular NGK's?

Share this post


Link to post
Share on other sites

I had a problem like this once, turns out I had lost the little plastic washer that sits above the needle/below the spring...just a try.......When was the last time it ran? What jets?

Share this post


Link to post
Share on other sites

You know what, I think I may have put that little plastic washer under the needle, I thought that was how it was when I first checked it, I'll have to check when I get back to the bike. Is that plastic washer supposed to be over the top of the needle or just under the lip on the needle?

the main jet is a 137.5, the needle has two little metal washers/shims under it, the snorkel has been removed and I run a supertrapp slip-on with 8 disks. This was how it was set up when I bought it and it ran strong all summer long like that. Thanks for the help.

Share this post


Link to post
Share on other sites

Well I know that there is at least one plastic washer that goes on TOP of the needle because that is what the spring makes contact on to push down the needle. I'm just wondering if there's supposed to be another plastic washer on/below the needle...I'm going to adjust my float today so I'll check. Funniest thing was that with mine the bike was running fine, until one day it didn't. I mean it would start, sometimes make it around the block, sometimes a few miles until it died. Or it would just barely idle and if I tried to throttle it would bog. AND I HADN'T TAKEN THE CARB APART, but when I opened it up that little white plastic washer on top of the needle was MIA!! Don't know where it went, or what happened (aliens messing w/ my carb??). BUt I put a new one in and presto :cry:

Share this post


Link to post
Share on other sites

If it helps, I have the exact same setup as you so your jetting sounds right on. I run a supertrapp(8 discs) open airbox, 137.5 main and two small washers to shim the needle.

Share this post


Link to post
Share on other sites

You see there's actually supposed to be two white plastic washers, one under the clip, and one on top of it to contact the spring (w/o the top one the needle doesn't get pushed back down)........

PICT0229.jpg

Hope this helps b/c its a cheap and easy fix if so!....

Share this post


Link to post
Share on other sites

that was it!!!! I took the top of the carb off and pulled out the diaphram and needle, and saw that both little plastic washers were under the needle (I'm still not quite sure when or how I moved it from over the needle to under it, but oh well). Now that I've looked at it more closely, I can see exactly why that one plastic washer needs to be on top. Funny thing though is that my friend who is a self-proclaimed motorcycle expert also missed this when I had him look at the carb when I couldn't find anything wrong with it. Thanks to all of you who helped me along through this diagnosis, My DR runs perfectly again.

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  

×