DR750 & DR800 owners thread

Discussion in 'Thumpers' started by MCmad, Jul 14, 2008.

  1. aapo

    aapo aapo

    Joined:
    Aug 13, 2008
    Oddometer:
    186
    Location:
    Finland
    HI,

    In 750s the power coil is in stator and the trigger is the black plastic one with smal "cylinder" in the magneto cover. DR 750 stator is available only from suzuki (some 500€:huh), but DR 800 you can cheaper.
    But with ignitec you can go with the

    http://www.electrexworld.co.uk/cgi-...exworld.co.uk/&WD=750 xrv&PN=G07.html#aG7#aG7
    "I heard" one guy in finland was about istal this stator on turbo dr 750. (there was a picture in thi thread some 2 years ago).

    anyway, you can keep the trigger, and use the place of ignition power coil to have some more power for hated grips, lights etc.
    But I haven't done it, so it's jus theory.

    Br: aapo
  2. motolab

    motolab Long timer

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    What did grips ever do to you?

    Regards,

    Derek
  3. motolab

    motolab Long timer

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    If you're switching to a battery powered ignition, you can then also go to TCI ignition instead of CDI (you'd have to install coils with higher primary resistance to go along with the TCI).

    Regards,

    Derek
  4. aapo

    aapo aapo

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    I'm sure they jumped in to the mysterious fuel system of CV mikunis and caused lean mixture and cylinder damage. Now i need some electricity to keep them in control and not to dominate my dr.

    Br: aapo
  5. Ladder106

    Ladder106 It's a short cut, really

    Joined:
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    Being well sick of the silly air filter system in both the SR41/42 and SR43. I went in search of something to allow me to fit a large cylindrical foam filter inside the box.

    I actually came up with something I think will work.

    Photos are from the SR43 airbox but I think the 41/42 is similar enough at the front so there will not be a problem.

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    I'm certain I'll be able to find some sort of filter to fit into the box and clamp to the adapter. The small end of the adapter can be had in 1 1/2 in. (as in photos) 2 in. and 3 in. openings. The 3 in. end fits very nicely into the inside of the airbox. It will have to be sealed with RTV and maybe a small round headed screw and nut top and bottom for insurance.

    I'll adjust the inside size to fit whatever filter I can source but will ovbiously try for the largest opening inside the box that I can find.

    Opinions???
  6. robmoto

    robmoto Long timer

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    Derick carn,t help you much, I bought a after market top end gasket set from Italy on Ebay and thought or a bonus valve stem seels included.
    Suzuki don,t include them with there gasket sets.
  7. aapo

    aapo aapo

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    Could the brand been Athena?

    Br: Aapo
  8. Hyena986

    Hyena986 Adventurer

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    Location:
    Romania
    The spring is finally here... 10-12 degrees Celsius and the sun is brighter than ever :freaky
    [​IMG]
  9. Megamoto

    Megamoto Yes, I do look like this.

    Joined:
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    Location:
    You know...I think I've been here before.
    Folks, I'm on the scrounge. Has anyone an unwanted right-hand drive headlight? Daisy is an import from Germany and is fitted with a left-hand drive headlight, the MOT testers are getting a bit more anal.

    If anyone can help I'm happy to cover all costs.
  10. spen

    spen on my arse

    Joined:
    Sep 21, 2009
    Oddometer:
    356
    Location:
    sunny ireland
    Here a list of bits i would like to replace on my 750 with ones that are in a better shape ,so if you have any of them please PM me ,thanks
    A UK spec headlight ,i have 3 lights but all off euro models MOT here is a bit stickey about the headlight beam.
    A set of MPH clocks ,even a trashed set i can nick the MPH dial off would do as again MOT here doesn"t like KPH clocks
    A decent front and rear disc ,the ones i have are worn so a better set would do the job.
    Thanks
  11. p3dro

    p3dro Adventurer

    Joined:
    Jan 8, 2010
    Oddometer:
    30
    Hello friends!
    My front brake was sticking this morning, and it made me fall over on some wet road-markings. So I took the calipers apart and, correct me if I'm wrong, but should there be rubber o-ring seals in this picture....?
    If so, anyone know where I can get a set?
    Thanks!
    Pete

    [​IMG]
  12. robszombie

    robszombie Adventurer

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    Apr 13, 2008
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    Location:
    Damp damp Ireland
  13. Ladder106

    Ladder106 It's a short cut, really

    Joined:
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    Standard Suzuki parts would likely be your best bet here the seals come as a set, I believe.

    If your pistons are as bad as the one in the photo, I'd suggest replacing those also. The one I can see looks pretty well done for.
  14. motolab

    motolab Long timer

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    If there is corrosion (i.e. brown colored buildup or a dull grey color rather than a bright "as machined" look) in the seal grooves (check the portions hidden from normal view with a dentists mirror), replacing seals and/or pistons will not help.

    Regards,

    Derek
  15. Ladder106

    Ladder106 It's a short cut, really

    Joined:
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    Sounds simple, right? Got MORE AIR, well...just add more fuel and everything is happy.

    The basic concept is sound but finding the place where everything is Juuuuust Right is a bit more difficult.

    WARNING:
    This is likely to be a long post so if airbox mods and jetting is not your particular interest just go on to the next post.


    This whole thing started when I transplanted a SR43 engine into a SR41 frame. I needn't go into the reasons for this mad scheme but I did it so that was the beginning.

    What I found was a motorcycle that wasn't very happy and wasn't making me very happy either.

    The first thing I learned is that you don't get a SR42 but just sticking a 800cc engine into the SR41. The primary gearing is different and while you get the extra cc's you also get a bike that's geared quite high.

    What I found was an engine that vibrated....a lot. More than I though was reasonable. First thing I did was to replace the balancer chain with a shiny new Suzuki part. That only made it sound smoother but didn't do much for the way it ran.

    NOTE: The bike is running with a 1000 cc GSXR silencer and standard Suzuki header pipe. I like the silencer tremendously for it's sound, fit, and the ability to accept a spark arrestor that will allow me to legally ride off-road in California. NO SPARK ARRESTOR AND MR. RANGER CONFISCATES YOUR BIKE....THEY ARE SERIOUS.

    It seemed that the engine wanted more air. So, my first step was to open a hole in the side of the air filter cover. I didn't want to loose the rubber snorkel at first so I removed as much material as possible leaving the snorkel in place.

    [​IMG]

    This made an obvious change in the way the bike ran. It was now surging and not running at all well about 3800 rpm or so. In any gear above that engine speed it would surge and would not be coaxed to pull over 4500. At the point it started surging I pulled the "choke" and the bike ran better. Not great but improved. My deduction was....more fuel.

    Figuring that if it was lean at mid-range, it would certainly be lean on top I elected to increased main jet sizes rather than just raising the needle.

    With a pair of 125 main jets installed and the filter lid as shown above, the bike ran quite well. It would pull top revs in all gears but would still not pull past about 5000 in top. I felt there was maybe more to be had so I opened the air filter lid as much as possible.

    [​IMG]

    Another test ride proved that more air was indeed getting into the engine since the dreaded lean-surging was back. It moved up the rev-range to the 5000 rpm level but the bike would not pull over 5500 or so in the lower gears.

    So....more gas, right?

    Next step was a pair of 130 main jets...............
    ...............and manged to move the surging a bit further up the rev range to 5500 with no pull over 6000. This time I went out with a roll of trusty Duct Tape. After a bit of fiddling about I got the bike to run really well (according to my butt-dyno) by sealing off a bit of the open air box. Thusly:

    [​IMG]

    I would have left it here but felt like I owed it to "science" to find a point that the bike would run well with the entire filter lid opened.

    So....even more gas? You betcha.

    Installed 132.5s. (Notice how I'm creeping up on the problem).........
    ........Getting closer. A hint of surging at 6000 in lower gears but still not pulling over 5500 or so in top


    Gotta keep going, so even more gas?

    My shop did not have any 135s available so my next step was 137.5........
    ........That DID IT. I was there......almost....because another problem had reared its head.

    AIR FLOW PAST THE HOLE: or the Bernoulli Effect, Pricipal, Law....thing

    With the pair of 137.5s installed the bike would pull top revs in all gears except the top part of 4th and 5th.

    With the SR43 primary drive and geared 15/47 at the final, the top of my 4th gear is over 85 mph.

    At this speed air was not flowing into the airbox as it should. By putting my hand in between the tank and the side panel and blocking the air directly in front of the filter, the bike picked up revs in 4th and ran better in the top part of 5th.

    Thinking that riding close to the TON on knobbies with one hand on the bars and the other stuck into the left side of the bike was a bit mad, I felt I had proved my point and set out to build some sort of "air-dam" or reverse-scoop to shield the intake a bit.

    Using my 3rd grade arts-and-crafts training I cut up a small plastic water bottle and stuck it onto the filter lid with Duct Tape (what eles?)

    Promise not to laugh, please. It's what they call "proof of concept" or something in the engineering labs. It wil be replaced in future with something much more permanent.

    [​IMG]


    It's crude, but, HEY....It worked. Pulled top revs in 4th and 6500 in top gear before the pavement ran out. Performance in the lower gears felt the same so I don't think I'm restricting the air flow down low. it just needed protection at higher speeds.

    As of this afternoon, I have refilled the tanks with Premium Fuel (yes it's still our E10 rubbish) and will now ride the bike in a sane "normal" way to see how I'm doing for milage/efficiency.


    This leads me to a recent post from Derek at motolab (no caps in the name, i checked). motolab (http://www.moto-lab.com/) is about 80 miles away from me but because I'm such a stubborn,lazy sod I have not been down to see him yet. Once I get this bike as sorted as I can, I plan to go down there and let him plug it into a wall and have a go at it with all the latest machines. This way he can tell me that everything I've done to date has been rubbish and we can both have lunch and a laugh.

    Anyways....here's Dereks post from the Pre 96 DR650 Thread on ADV.

    So my question to Derek is:

    What's the next step? Lower the fuel level in the bowls, or raise the clips and drop the needles?

    First answer: Stop fumbling about, come to the shop so we can see where you are and find out where you want to go.

    I know this, but if we can assume I wont do that right away, what would be your next step?

    Over to you at motolab...................................................
  16. motolab

    motolab Long timer

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    Is this dam forward or rear facing?
    Before anything else happens, you must first make sure that main jets are installed that are correct for the leanest area of the fuel delivery curve for WOT. Then you would see at what rpm the richest area is, and by how much it is too rich. Next comes a judgement call to determine whether a uniform mixture across all rpm at WOT can be achieved via a change in needle shape, emulsion tube size, fuel level and/or main air correction. Some of the the decision-making process may well be predicated on parts availability, i.e. what other needle shapes and emulsion tube sizes can be sourced. Once all of these variables are considered, the path that could unfortunately reveal itself might be not opening up the airbox quite this far. When I do this here, I open up the airbox until I know that I'm at the limit for what can be compensated for with the parts that I have access to.

    Regards,

    Derek
  17. Ladder106

    Ladder106 It's a short cut, really

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    The opening faces the rear of the bike. Sorry, forgot you were not DR750 oriented.

    So, it would seem that pluggin it in is the next logical step.

    The hole is in the air filter lid. On this bike the lid forms the left side of the airbox. Air enters through the center of the filter then out into the airbox before being taken into the carbs. I have other new air filters that are not opened any more than stock. That's why I felt pretty free with this one.
  18. motolab

    motolab Long timer

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    It's likely that the dam produces a vacuum inside the airbox at speed, meaning that the mixture at the same combination of throttle position and rpm would be different at a different road speed, which is clearly undesirable. It would be interesting to remove the dam and install larger main jets until the problem goes away. If the mixture is then too rich in the leanest spots at WOT on the dyno, that would demonstrate that the opening must be located in relatively still air.

    Regards,

    Derek
  19. Ladder106

    Ladder106 It's a short cut, really

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    I was afraid you'd say something like that.

    I've been thinking about redesigning the air box.

    I'm planning to seal up the left side of the box, use a cleanable foam filter that operates in the normal (dirty air on the outside clean air on the inside) way.

    Then opening a hole on the top of the box under the seat. Probably the best place for relatively still air. I have 15mm between the bottom of the seat and the top of the airbox
  20. Ladder106

    Ladder106 It's a short cut, really

    Joined:
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    Oddometer:
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    I was trying to somewhat duplicate what the Suzuki guys did. The standard air filter lid (left side of the airbox) looks like this (without the triangular hole in the front)

    [​IMG]

    The black airdam is connected to a short "snorkel that protrudes about 30 mm into the airfilter area.