DR350 Thread

[SFC_Ren]

Originally Posted by thump!

If you haven't already done so, remove the EPA seal over (actually under) the idle mixture screw and back that little guy out about 1/2 - 3/4 turn. Makes a huge difference in starting.

The idle mixture screw had already been unplugged and messed with. I'm setting it at two turns out from fully seated to start with. The jetting in the carb is all stock with the idle jet being #37.5 and the main jet is a #135. It seems to run well even with the airbox cutout and the cobra pipe but I suppose it should be running lean.

Thanks for the suggestions.

[e28rusty]

I recently bought a project from my buddy, it's a street legal '90 dr350. He bought it last year and road it for the season before buying a drz. He replaced the carb with a new tm33 and after riding it with the new carb for a few months we installed a keintech header and fmf muffler, while we were dialing in the jetting with the new pipe it was acting a bit weird and eventually stopped running well at all. Now it won't rev all the way out.

I have cleaned the carb very thoroughly several times and changed the main jet out from 127.5 to 142.5. It runs best with the 127.5, but it still won't rev all the way. I'm pretty sure something isn't right because it should run aruond a 140. Pilot is stock. The choke (enrichment) doesn't seem to have much impact on how it runs at all.

the bike idles and runs great, even at WOT, until you get it revved up. I've been screwing with the carb so much with negligible impact I'm wondering if it could be cdi. Or could there be fuel leaking through somewhere making it run way rich?

Any help would be great, sympathy is also appreciated.



The video is with a 140 main jet, it took me about 200 kicks to get it fired up, when it was running right it would start after 2..
It's pretty loud, you might want to turn it down before watching.

[thump!]

Originally Posted by SFC_Ren

The idle mixture screw had already been unplugged and messed with. I'm setting it at two turns out from fully seated to start with. The jetting in the carb is all stock with the idle jet being #37.5 and the main jet is a #135. It seems to run well even with the airbox cutout and the cobra pipe but I suppose it should be running lean.

Thanks for the suggestions.

I'm sure some will disagree but reading the thumper treads here and on thumpertalk reveals a fairly consistent reoccurring theme for me. I think cutting the airbox or removing the lid makes a kick start single harder to start. Since a single gets only one opportunity to fire for each two revolutions there are about 540 degrees of revolution when air isn't moving through the intake tract at all. Unlike electric start that keeps air moving thru the intake repeatedly in rapid succession, the kickstarter DR350 passes thru only one intake and compression stroke per kick and there is a relatively long pause while the operator resets to kick again. Doesn't matter how hard you kick it, the gearing of the kickstarter provides only ONE chance to fire so conditions need to be right at that precise moment. I'm not sure WHY the lack of airbox resistance results in hard starting on kickstarter bikes but I'm convinced it does.

[kobukan]

Originally Posted by thump!

I'm sure some will disagree but reading the thumper treads here and on thumpertalk reveals a fairly consistent reoccurring theme for me. I think cutting the airbox or removing the lid makes a kick start single harder to start. Since a single gets only one opportunity to fire for each two revolutions there are about 540 degrees of revolution when air isn't moving through the intake tract at all. Unlike electric start that keeps air moving thru the intake repeatedly in rapid succession, the kickstarter DR350 passes thru only one intake and compression stroke per kick and there is a relatively long pause while the operator resets to kick again. Doesn't matter how hard you kick it, the gearing of the kickstarter provides only ONE chance to fire so conditions need to be right at that precise moment. I'm not sure WHY the lack of airbox resistance results in hard starting on kickstarter bikes but I'm convinced it does.

I would be one to disagree. I have a '99 DR350 dirt model with a pumper carb and opened up airbox - it usually starts (15k miles so far) on the first kick (sometimes takes two) regardless of whether the bike is warm or cold, and in any temps - winter or summer. I've started it in a couple kicks in temps below 0°F (one crazy day I took a short ride when it was -2°F). I think if the bike is tuned properly and everything is functioning as it should, the bike should start easily.

[MrPulldown]

Originally Posted by e28rusty

I recently bought a project from my buddy, it's a street legal '90 dr350. He bought it last year and road it for the season before buying a drz. He replaced the carb with a new tm33 and after riding it with the new carb for a few months we installed a keintech header and fmf muffler, while we were dialing in the jetting with the new pipe it was acting a bit weird and eventually stopped running well at all. Now it won't rev all the way out.

I have cleaned the carb very thoroughly several times and changed the main jet out from 127.5 to 142.5. It runs best with the 127.5, but it still won't rev all the way. I'm pretty sure something isn't right because it should run aruond a 140. Pilot is stock. The choke (enrichment) doesn't seem to have much impact on how it runs at all.

the bike idles and runs great, even at WOT, until you get it revved up. I've been screwing with the carb so much with negligible impact I'm wondering if it could be cdi. Or could there be fuel leaking through somewhere making it run way rich?

Any help would be great, sympathy is also appreciated.



The video is with a 140 main jet, it took me about 200 kicks to get it fired up, when it was running right it would start after 2..
It's pretty loud, you might want to turn it down before watching.

Sounds jsut like Rugged's bike

[Suzuki Phil]

Originally Posted by thump!

I'm sure some will disagree but reading the thumper treads here and on thumpertalk reveals a fairly consistent reoccurring theme for me. I think cutting the airbox or removing the lid makes a kick start single harder to start. Since a single gets only one opportunity to fire for each two revolutions there are about 540 degrees of revolution when air isn't moving through the intake tract at all. Unlike electric start that keeps air moving thru the intake repeatedly in rapid succession, the kickstarter DR350 passes thru only one intake and compression stroke per kick and there is a relatively long pause while the operator resets to kick again. Doesn't matter how hard you kick it, the gearing of the kickstarter provides only ONE chance to fire so conditions need to be right at that precise moment. I'm not sure WHY the lack of airbox resistance results in hard starting on kickstarter bikes but I'm convinced it does.

It's because carburetors work on pressure differential, if you change either side you've screwed things up (valve timing exhaust, air cleaner etc).

I've had my 96 DR350SE for six years and run the stock CV carb and airbox, no issues, great power, excellent gas mileage. Leave the stock carb on and go riding.

SP

[Anonawesome]

Originally Posted by Suzuki Phil

It's because carburetors work on pressure differential, if you change either side you've screwed things up (valve timing exhaust, air cleaner etc).

I've had my 96 DR350SE for six years and run the stock CV carb and airbox, no issues, great power, excellent gas mileage. Leave the stock carb on and go riding.

SP

Leave everything stock? I don't-......I can't even-......


No comprendo

[2bold2getold]

From My Experience. (I've pretty much done nothing but work on motors all my life. In 1952 at 8 yo I was flying 1/2 A control line model airplanes with those little Cox .049 motors. If you could make those little things run you can probably make any thing run. Read every word of every Rod and Custom and HotRod magazine.
First car was a "49 Ford flathead V8. Put 3 Stromberg 97s on it with scavenger pipes. Thought I was cool. Had a "53 Belair Convertable. "59 Belair Hard Top, "65 GTO and a "68 Dodge Charger R/T 440 Magnum 375 HP. USAF Missle Electronics Guidance and Control Technician. Not quite rocket science, but pretty close. Opened my auto repair shop in "72 and averaged more than 2 major overhauls a week from "72 to "90, mostly air cooled VWs. Built a 440 for my 360 Dodge Maxi Van, Put a turbo on a VW Bus, built a motor for a Formula V race car, built a 4 carb Corvair for a Porsche 912, built buggy motors with two 2 barrel Webers (Webers are great) and Delortos. In "91/"92 ran a Cat 963 Track Loader at McMurdo Station in Antarctica. Closed my shop in "95 and went to work for a rental equipment co/ John Deere Dealer untill I retired. Finished 10th in the Texas State Enduro Circuit(250 class) in "74. Finished 9th in the Texas State Trials Championship Master Class in "76. Rides in Colorado, Mexico, New Mexico, Arkansas, Contintal Divide Trail and ~ 1/3 of the TAT.) Sorry for the long winded list of credits,got carried away and memory lane is just fun.

Again, From My Experience. When you walk up on an cold bike that's been sitting for a few days or months, more than likely it's in a lean condition. It's probably not gonna start like that. Now, you can either apply the choke and kick/crank from that lean condition untill you get it rich enough to start or some how add enough fuel ( pumper squirt or pour some gas down the carb throat/remove the plug and add fuel) to make it a little rich and open the throttle to add air and kick/crank untill it gets lean enough to start. Down in Antarctica when it was 60 below zero and the big diesels wouldn't start we would soak a shop towel with gas and wrap it around the air filter. Knocked like hell, but it got em started. I don't recommend doing that. I'm sure you have had trouble starting your weed eater or mower after it has been sitting all winter, Dump the old gas, add fresh gas, pull the plug and put a LITTLE gas in the plug hole, open the throttle all the way and crank. It may only run a few seconds untill the prime is gone, but then it's in the right air/fuel condition to start. Works good for bikes too. Of course all of this assumes the rest of the motor is in good operating condition. BIG ASSUMPTION. So you guys with the e-start or pumper carbs have a little advantage (as long as you don't flood them) when it comes to starting. The kick start models with the CV carbs are gonna be the harder to start. That's why Greg says he kicks his through several times to prime it before he trys to start it. But then the guys with the CV carbs are gonna get better gas mileage and better altitude compensation. There are always trade offs. Hope this helps.

[RuggedExposure]

And this is what happens when you pop wheelies in cowboy boots with no seat on the bike:


Gonna go straighten out the bars now and take it for a ride on the trail.

[markk900]

Totally unfair Rugged! If its running well enough to throw you off I NEED TO KNOW WHAT YOU DID!

(ps. rash doesn't look horrible but it'll sting for a while!).

[smc5735]

Hey everyone,

Just a question on how to remove the forks from a 97' DR350SE. The reason is because I purchased new fork boots and will be replacing the old yellow ones with new black day star boots.

The forks are stock on my bike, I'm assuming I have to put the boots on from the top of the forks once they are off.

Thanks in advance!

[MrPulldown]

Originally Posted by smc5735

Hey everyone,

Just a question on how to remove the forks from a 97' DR350SE. The reason is because I purchased new fork boots and will be replacing the old yellow ones with new black day star boots.

The forks are stock on my bike, I'm assuming I have to put the boots on from the top of the forks once they are off.

Thanks in advance!

the fork legs are held on by the clamps on top, thing the handle bars attach to. Undo the 4 pinch bolts on each side. Two on the top clamp two on the bottom. It would be best to remove the front wheel, and remove each leg seperatly. Once at this point jsut pull each leg down. Might have to pry open the clamps with a screw driver. Might need to remove the brake caliper on one side and the speedo cable guide on the other.

Make sure you note how far up on the fork legs it was clampped. Mark with sharpie, so that you know where to reinstall them.

[FireDog45]

Originally Posted by e28rusty

I recently bought a project from my buddy, it's a street legal '90 dr350. He bought it last year and road it for the season before buying a drz. He replaced the carb with a new tm33 and after riding it with the new carb for a few months we installed a keintech header and fmf muffler, while we were dialing in the jetting with the new pipe it was acting a bit weird and eventually stopped running well at all. Now it won't rev all the way out.

I have cleaned the carb very thoroughly several times and changed the main jet out from 127.5 to 142.5. It runs best with the 127.5, but it still won't rev all the way. I'm pretty sure something isn't right because it should run aruond a 140. Pilot is stock. The choke (enrichment) doesn't seem to have much impact on how it runs at all.

the bike idles and runs great, even at WOT, until you get it revved up. I've been screwing with the carb so much with negligible impact I'm wondering if it could be cdi. Or could there be fuel leaking through somewhere making it run way rich?

Can I assume that it will rev up if you SLOWLY roll on the throttle? If that's the case I would look at fuel flow. Start at the petcock and move in to the float. Did you check float height? You said you cleaned everything but what did all the rubber bits look like?

I'm just throwing darts here but my gut is telling me you're running away from fuel. Of course that's assuming my first sentence is correct, if not i got nothin...

[mustangwagz]

Originally Posted by RuggedExposure

And this is what happens when you pop wheelies in cowboy boots with no seat on the bike:


Gonna go straighten out the bars now and take it for a ride on the trail.

IS IT running properly and correctly 100%? If so, you best be posting what ya came up with RE...cuz its been like Forever ago that this happend, fuck...you even went and bought a different bike...lol i see the DR gave you a booboo for trading it in! LOL So whatd ya come up with??

[e28rusty]

Originally Posted by FireDog45

Can I assume that it will rev up if you SLOWLY roll on the throttle? If that's the case I would look at fuel flow. Start at the petcock and move in to the float. Did you check float height? You said you cleaned everything but what did all the rubber bits look like?

I'm just throwing darts here but my gut is telling me you're running away from fuel. Of course that's assuming my first sentence is correct, if not i got nothin...

It behaves the same no matter how fast you crack it. It has a raptor petcock and the float is just below the seam.
The rubber looks new, and there's no varnish or anything in there. It looks like a new carb.
I just snagged a used cdi on ebay so we'll try that in 3-5 business days, I'm not really sure what else could be going on.