07 drz400sm high oil consumption and high speed wobbles
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Thread: 07 drz400sm high oil consumption and high speed wobbles

  1. #1
    Join Date
    Feb 2017
    Posts
    2

    Default 07 drz400sm high oil consumption and high speed wobbles

    hello everyone!

    i recently bought a used 2007 drz400sm with ~24000kms(~15000miles) and i can say it has a good power runs great but by time im discovering some problems that might be serious..

    so the bike has a full yoshi pipe
    3x3 air box mod
    k&n air filter
    jd jetting currently running with 160# jet and the thinner needle (clip on the 3rd from top)

    so the first problem i noticed was while i was cruising about 90-110kmph(55-70mph) the bike was slightly cutting out and coming back, going back and forth like it was running out of gas.. but when i accelerate at those speeds it goes fine till i hold the throttle steady again.. really annoying shit so i guessed it was something wrong with the carb..so i tapped the 3x3 hole on the air box to see if it was lean or rich and yeah it fixed it a little bit.. so in the end i taped about 2/3 of the of the 3x3 hole and it was going ok..
    after few days i went for a ride and it did it again so i thought maybe change the oil.. i drained the oil from the frame and engine and all together was 1500ml(motul 15/50 semi-synthetic)..so i changed the oil and filter and put 1800ml(motul 15/50 full-sythetic) and the oil was higher than the highest mark on the dipstick.
    took the bike for a ride and WOW it was running great! no wobbles no shitty cruising anymore!

    After a few days i took it for a ride for about 1 hour non-stop. and while i was cruising it started to wobble back and forth like it was running out of gas again.. i stopped, waited for about 2-3 min and checked the oil and the oil was barely touching the dipstick.. went back home, drained the oil and again found there was only 1500ml of oil in there... it consumed about 300ml of oil in about 200km(125miles)...

    Is this happening because i put a full-synthetic oil in it?? what do you guys think? need more opinions and suggestions because I told a pretty good motorcycle mechanic about it and he told me that most probably i need a new piston and set of rings but really need you guys to tell me what you think!

    also if in the end of the day i need to change the piston and ring what do you guys recommend? that guys told me to not buy any high-comp pistons and its better to put OEM piston and rings to not have problems in the summer because it gets really hot over here.. (btw OEM piston kit here is about 200euros) what about wiseco/vertex/ etc etc?

    thanks a lot for any help and sorry for my english..

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  3. #2
    Join Date
    Jul 2016
    Location
    Vancouver Canada eH?
    Posts
    46

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    Quote Originally Posted by soheil View Post
    hello everyone!

    i recently bought a used 2007 drz400sm with ~24000kms(~15000miles) and i can say it has a good power runs great but by time im discovering some problems that might be serious..

    so the bike has a full yoshi pipe
    3x3 air box mod
    k&n air filter
    jd jetting currently running with 160# jet and the thinner needle (clip on the 3rd from top)

    so the first problem i noticed was while i was cruising about 90-110kmph(55-70mph) the bike was slightly cutting out and coming back, going back and forth like it was running out of gas.. but when i accelerate at those speeds it goes fine till i hold the throttle steady again.. really annoying shit so i guessed it was something wrong with the carb..so i tapped the 3x3 hole on the air box to see if it was lean or rich and yeah it fixed it a little bit.. so in the end i taped about 2/3 of the of the 3x3 hole and it was going ok..
    after few days i went for a ride and it did it again so i thought maybe change the oil.. i drained the oil from the frame and engine and all together was 1500ml(motul 15/50 semi-synthetic)..so i changed the oil and filter and put 1800ml(motul 15/50 full-sythetic) and the oil was higher than the highest mark on the dipstick.
    took the bike for a ride and WOW it was running great! no wobbles no shitty cruising anymore!

    After a few days i took it for a ride for about 1 hour non-stop. and while i was cruising it started to wobble back and forth like it was running out of gas again.. i stopped, waited for about 2-3 min and checked the oil and the oil was barely touching the dipstick.. went back home, drained the oil and again found there was only 1500ml of oil in there... it consumed about 300ml of oil in about 200km(125miles)...

    Is this happening because i put a full-synthetic oil in it?? what do you guys think? need more opinions and suggestions because I told a pretty good motorcycle mechanic about it and he told me that most probably i need a new piston and set of rings but really need you guys to tell me what you think!

    also if in the end of the day i need to change the piston and ring what do you guys recommend? that guys told me to not buy any high-comp pistons and its better to put OEM piston and rings to not have problems in the summer because it gets really hot over here.. (btw OEM piston kit here is about 200euros) what about wiseco/vertex/ etc etc?

    thanks a lot for any help and sorry for my english..
    some things i'd suggest:
    1. Check the JD instructions to see that you're on the right needle for where you are. sounds like you've got the wrong needle/jet for where you are if the bike is running better when it can't breathe.
    2. drain the gas, check the fuel screen on the petcock; it can get clogged with crud causing weird gas issues at WOT top speed, filter gas through coffee filter before putting back in the tank, or better, toss the gas into your truck and get fresh gas
    3. burning oil means that it prob needs a rebuild, most DRZ's do around 25-30K km; good time to do the big bore kit as its the same price and you get some more jam out of it. you can build up DRZ's without too much issue, my buddy had a reliable 55HP one (MRD, cams, B-bore, thinner base gasket, FCR carb), so don't feel like another 5HP means that you're building a grenade. you should get a kit with a piston, cylinder, rings, check valves. you'll get another 20K out of it. burning oil at high rpm is normal due to piston blow-by which is more exaggerated with valve or piston/ring/cylinder wear. mine ran best with Motul 10-40

  4. #3
    Join Date
    Feb 2017
    Posts
    2

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    Quote Originally Posted by Kwota2.0 View Post
    some things i'd suggest:
    1. Check the JD instructions to see that you're on the right needle for where you are. sounds like you've got the wrong needle/jet for where you are if the bike is running better when it can't breathe.
    2. drain the gas, check the fuel screen on the petcock; it can get clogged with crud causing weird gas issues at WOT top speed, filter gas through coffee filter before putting back in the tank, or better, toss the gas into your truck and get fresh gas
    3. burning oil means that it prob needs a rebuild, most DRZ's do around 25-30K km; good time to do the big bore kit as its the same price and you get some more jam out of it. you can build up DRZ's without too much issue, my buddy had a reliable 55HP one (MRD, cams, B-bore, thinner base gasket, FCR carb), so don't feel like another 5HP means that you're building a grenade. you should get a kit with a piston, cylinder, rings, check valves. you'll get another 20K out of it. burning oil at high rpm is normal due to piston blow-by which is more exaggerated with valve or piston/ring/cylinder wear. mine ran best with Motul 10-40
    so you think if i buy a big bore kit is the same reliable as the stock??
    btw if i dont do the big bore are vertex piston good on drz's?

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