DR350 Thread

Discussion in 'Thumpers' started by leonphelps, May 16, 2007.

  1. kaukasion

    kaukasion Adventurer

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    i pulled and inspected it but it seemed ok to me wasnt very dirty
    do you think that would make such a huge difference in power?
    if so could i test this theory by simply removing it and going for a ride to test if its hurting my power without hurting the engine?

    thanks for the help guys im new to bikes and this is my first street bike so i dont know much more then what i have researched online i have a good understanding of engines and mechanical things just havent much experience in bikes in particular
  2. MrPulldown

    MrPulldown Long timer

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    DR350 is not quit a "street bike". Do not pull the air filter and run the bike. Fuel air mixutre will be too lean. If it looks clean it probably is. Mine is always dirty and it runs ok and looks dirty.

    I have gotten my DR up to 80+mph (gps confirmed). In fact it was right before or after when my profile picture was taken. Dry lake bed of black rock desert. Everything powerwise is stock on my bike.
  3. kaukasion

    kaukasion Adventurer

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    i should have phrased or worded that better
    what i meant was this is my first non 2stroke bike the only other being a cr250r

    ok ive also thought of some other things it hasnt been rode since yesterday about 30 miles pinned in 6th at between 40-55mph "hilly roads" would the plug tell me much about if its running stoich? or would the evidence be gone from the few miles of it that were in town once i hit town?

    ive also read that i could partially open the choke while flat out and see if i pick up the extra power to prove a theory of lean condition but im afraid of fouling out the plug by doing this

    im really starting to think i may not have gotten the slide diaphragm seated correctly "was being a pain in the ass to get to sit in is grove" i think i got it right after about five mins of messing with it and the cap seemed to seat evenly and smoothly after some fighting with it not wanting to stay in place

    ive heard a pinched diaphragm can cause a lack of power like this even from a slight pinch but it seems to me that it would have a bigger loss of power across the entire rpm range but it seems to be fine just weak in the top say 5k to redline range but possibly lifting the slide still but just not letting the needle come all the way out of the main jet?

    i have the bst33 carb
    also could this be a vacuum leak?
    i had an extra hose after putting everything back together that i didnt remember where it went i looked up online and found where someone said it was a vent that just goes upwards toward the frame so i did that and it isnt connected to anything just pointing upward from the carb, its on the opposite side as the choke, and no its not the vac line for the vacuum petcock i capped it off with a vac line cap i bought from autozone
  4. shearboy2004

    shearboy2004 KIWIINUSA

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    What elevation do you live at ?
  5. kaukasion

    kaukasion Adventurer

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    im in central illinois so id imagine that is not a whole lot above sea
    a quick check on google netted this
    ~600ft above sea level
  6. shearboy2004

    shearboy2004 KIWIINUSA

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    Well that's certainly not the problem then , the stock jetting you have used should be just fine there .

    It should quiet easily pull 70mph for you so I'm guessing another wee trip through your carb may find something .
  7. 2old2Bbold

    2old2Bbold was 2bold2getold

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    I don't think a rider wieghing 250lbs is going to top out a lot different from a rider weighing 150lbs, on flat and level, no wind etc. Might get there a little slower. Recently, at near 6k ft, I had my stock '98se at 65mph (GPS). That was as fast as I felt comfortable running the bike. Any more felt like it was hurting the engine. But that's just me. Don't like that feeling. I know a lot of people run faster and more rpms, and some get away with it (for a while). Things that can make a difference : Gearing, Intake/Exhaust restriction, Jetting, Brakes, Bearings, Fuel/flow, Over all condition - tires, chain/sprockets, the list goes on and on. 50mph doesn't sound right, with stock gearing.
  8. dav_dman

    dav_dman Been here awhile

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    chk compression then if good then take the carb apart again.
  9. MrPulldown

    MrPulldown Long timer

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    Not so easy to do.
  10. thetourist

    thetourist Just passing thru

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    If you have 16 tooth on the front you are geared "High". The bike may be bogging a bit with the tall gearing. Knock it down a gear and see what happens. You should be able to pull 60-70 in 5th,

    My SE runs about 6000rpm at 60 in 5th. 55-5700 in 6th. That is with a 15 front sprocket.

    When pulling onto pavement I usually run up to 50mph, or more,in 4th getting up to speed. That is with 350 lbs of me and gear.
  11. mustangwagz

    mustangwagz Been here awhile

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    yah, what exactly is the easiet way to check compression with these bikes? i have tried to kick mine over without decomp and its a beeeech! then i read about ppl cracking the cases so i never tried again. lol the person i got my bike from had it serviced before i bought it, the ppl @ dealership did comp chekcs while using the de-comp lever and reported on the work report that it was "low" on compression. I just giggled and said, yah it'll be ok. hahahaha
  12. slartidbartfast

    slartidbartfast Love those blue pipes

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    If you have the CV carb, I'll suggest the diaphragm is torn. That means that you are only getting about 1/4 throttle or less, even when you think you are WFO. Valve timing off by a tooth could also cause you to lose a lot of top end power (but would require PO to have taken it apart) and so could a plugged exhaust (wasp nest perhaps?)
  13. 2old2Bbold

    2old2Bbold was 2bold2getold

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    If you don't have the automatic compression release, you could probably tow it. Be Carefull !!! Some ACRs hold the exhaust valve/s open a little while cranking to reduce cranking compression. Not sure how this one works. Hope I don't have occasion to find out. Might be able to loosen the exhaust valve clearence enough to by pass the ACR enough to check compression. I'm sure someone here will know if this will work or not.
  14. dirtyleg

    dirtyleg Adventurer

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    Just sent the DR350 down the road with new owner, Happy Trails to them.:wave:wave
  15. Ghostyman

    Ghostyman Been here awhile

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    I just torqued my shift drum bolt and also found that my clutch basket bolt had been completely loosened and was only held on by the lock washer. I torqued it down to 40 ft.lbs and then reassembled everything. Now I can barely shift. The lever takes a lot of force and I can't get past 3rd gear.

    I pulled the clutch cover and basket off. The problem seems to be related to the shift drum bolt itself. When I have the bolt torqued, I can barely change gears. When it's loose, I can switch gears. I was careful and torqued it to 8 ft.lbs. when reinstalling.

    Any ideas?

    Oh yeah, how much drag should there be when rotating the clutch basket? With the nut torqued to 40 ft.lbs, I could spin it by hand but it took a little effort. Is that normal or should it spin freely?
  16. Greg Bender

    Greg Bender Long timer

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    Hmmm...did you maybe bend the "L" shaped piece with the spring on it? IME, it is hard to see any bends until you remove it and examine it. That *might* cause the symptoms you describe.

    IIRC, the clutch basket should spin freely. Perhaps you need to clearance it?

    Regards,

    Gregory Bender
  17. Domromer

    Domromer Desert Rat

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    I did a search but couldn't find a dr250 thread...I just had to share this little gem with you guys..I wish I had more room in my garage..for me this is just about the perfect little dual sport..yes 100cc extra would be nice but damn the owner has this kitted out right..I have no connection with this bike..just in my local craigs list and I love little air cool thumpers.

    http://charleston.craigslist.org/mcy/3301156297.html
  18. Crenshaw

    Crenshaw Bum

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    Hi all, lurked here for a while while gleening valuable dr350 info before buying one. Let me first say thanks to everyone for contributing all the information on this site.

    Here is my "new" beater 1990 DR350. It's a dirt model, titled and plated. Some kind of rear rack, IMS tank, other random bits like bark busters, PD rear sprocket, etc... Mileage unknown.
    The PO only owned it for 6 months or so while he replaced the cam and rockers (worn due to suspected stint of running low on oil). He had only put about 30 miles on it while he owned it and acted like I was crazy for preparing to ride it 100+ home to Salida, CO from Colorado Springs. It held up just fine.
    I've changed the oil, adjusted the valves, checked the filter, and she runs like a champ.

    I've been putting some miles on it in the past few weeks and am really really impressed with it. For a guy who's been off of motorcycles for 5+ years and lacking experience riding off road, I think this is the best bike I could've stumbled in to.

    However! It seems to burn more oil than it really ought to after prolonged highway running. It has 15/44 gearing on it and I don't run more than 65mph on the highway usually, so I don't feel like I'm beating on the engine too bad. Seems to hardly burn any oil if I'm just bombing around in the woods without running at high speed. I don't have a tach, so not sure of what rpms I'm turning on the highway.
    I've heard these can burn a little after long stints of high rpms, but it seems like I have to add 100ml or so after every ride that includes that type of riding.

    Bad rings? It runs great and feels like (to me) it has plenty of power. Runs just barely faster than my friends old DR400 from a roll. Compression feels pretty good though I don't usually find it necessary to use the decomp lever when starting.
    Valve stem seals?

    Where do you guys recommend getting parts from should I decide to refresh this thing this winter?

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  19. Greg Bender

    Greg Bender Long timer

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    Welcome and good find! I've ridden my dirt model 1993 DR350 at 65 MPH all day long with 15/41 gearing - no problem at that speed. As for oil consumption, a couple of years ago I found a stuck oil ring that was causing my oil consumption problems. I fit new rings and had the cylinder ball-honed. My machinist also performed a basic valve grind, but the valves and guides were fine (I fit new valve guide seals at that time). Since then, oil consumption was greatly reduced. Oh, I'll still burn some when I go on long, multi-day trips, but nothing I'm concerned about.

    Hope this helps!

    Regards,

    Gregory Bender
  20. rubberband

    rubberband Will ride for tacos

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    I had similar issues...if you look far enough back in this thread. I changed the old hardened valve seals, while I was in there I tossed in a new piston, rings, and valves....no oil issues since.