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drz400sm burning oil after rebuild! HELP!!


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hello everyone!

 

About a month ago i rebuild my drz because it was burning too much oil so put in a new piston+rings, new cam chain, new valve seals and also cleaned the valves until they looked new! also changed the oil and oil filter. (10w40 100%synthetic)

My mechanic told me to ride the bike easy for the 1st tank (about 1/4 of the throttle), 2nd tank about 1/2 throttle, 3rd tank ride it good but dont rev the shit out of it... he told me to take it till 5 tanks of gas riding it smoothly just to be safe..

Well i rode the bike 1/4 to 1/2 throttle for about 150km (not even 1 tank)  and then rode it like i stole it.. that one tank seemed to never end!! :D

After 1000km it consumed oil again (about 100ml) so i added some to it and my mechanic told me that this is normal.

Now after 600km it almost lost about 150ml!!

NOW is this thing normal??? im beginning to think maybe is the synthetic oil the problem or maybe its because i wheelie too much or its because i rode the bike till max speed a couple of times..  1600km after rebuild and lost about 250-300ml oil..

What do you guys think??? 

thanks!

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 Synthetic for the first 4-500 miles is not a good thing , it doesn't allow breakin to happen . I would put some regular dyno oil in it then go out and do a bunch of engine braking steps . Get it going in 2nd or 3rd and speed it up fairly high rpms , don't bounce it off the limiter though, once it gets up to higher rpms let off the throttle but don't pull in the clutch or use the brakes , use the motor to slow you down . Do that 10-15 times in various gears . This helps rings seat better and forces the rings out against the walls .

I tested one motor after rebuilding it , before firing it up the first time I tested compression it was like 90psi, then I spun it over with the starter for 10-15sec ,making sure the oil pump was primed and pumping then tested it again , it had gone up  a bit already . I then fired it up for 1 minute and tested it again , the compression was already up to about 140(I forget the exact number these days). I then ran it for 10 minutes down the road , being somewhat easy on it , tested it again and it was already close to full comp 185-190( though this was a high comp motor and had more to go). After another 15min of up/down rpms and engine braking it was done moving when I tested it @ 208psi and it has stayed there since. So basically it was done "breaking in" by 20-30min. Now with an entirely new motor there is more to it than the piston/rings/cylinder, bearing, gears, bushings ect.... all need to burnish in so it'll take a bit longer .

 

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Edited by jjktmrider
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Every new vehicle built today comes from the factory with synthetic oil.

My reason to break in on dino oil is that I'm going to pitch it in 500 miles.

Sounds to me like you got a little zealous and scorched you rings, and maybe your piston. Maybe the piston can be saved and you can re-ring it.

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I don't think I've ever seen a reputable professional engine shop(auto, bike, quad, race shop ect..) say it's fine to use synthetic the first oil change , I've always seen specifically " do not use " . But to each there own , I've never wanted to try it ,too much money invested and you never know , this may be one of those cases . May just take longer for full break-in but otherwise it's fine . Who wants to build 2 motors and test as I did to see how fast it takes for each ?

 

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Edited by jjktmrider
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hey, thanks for the replies everyone!!

 

so im going to change my oil to a 15w40 non-synthetic oil, "brake in" again as "jjktmrider" said and see.. will not baby this bitch anymore!! hope it works after 2000km of hard ride :banghead:..

thanks again guys! ill update the results..

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hello guys!!

so on 27036km i changed oil (1750ml 10w40 motul full synthetic)

now after about 500km i drained it and about 1700ml came out (maybe a tiny little bit more..)

so changed to dino oil (about 1780ml motul 10w40), did a lot of accelerating and engine stops with all gears, i think (if not paranoid) i noticed that the bike is more stable when idling..im not sure though..

also i have this pinch black oily pipe after every hard ride (talking about the inside of the muffler).. is it possible that the packing of the muffler is still oily from before?? should i repack it or it will go away?? its a yoshimura btw..

cheers!:cheers:

 

Edited by soheil
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39 minutes ago, soheil said:

hello guys!!

so on 27036km i changed oil (1750ml 10w40 motul full synthetic)

now after about 500km i drained it and about 1700ml came out (maybe a tiny little bit more..)

so changed to dino oil (about 1780ml motul 10w40), did a lot of accelerating and engine stops with all gears, i think (if not paranoid) i noticed that the bike is more stable when idling..im not sure though..

also i have this pinch black oily pipe after every hard ride (talking about the inside of the muffler).. is it possible that the packing of the muffler is still oily from before?? should i repack it or it will go away?? its a yoshimura btw..

cheers!:cheers:

 

Can't hurt to re-pack it and see if it loads up again.

 

Quote

Corvette ZR1 High Tech LS9 - First Look: Building The ZR1's 638HP Engine

http://www.superchevy.com/how-to/project-cars/sucp-0811-corvette-zr1-high-tech-ls9/

 

Quote

Mobil 1™ advanced full synthetic motor oil has served as the factory fill for Chevrolet Corvettes and the recommended service fill for all Corvettes since 1993. As the Corvette evolved into the current world-class C7 sports car, the formulation of Mobil 1 motor oil advanced to meet the demands of these modern high-performance engines.

https://mobiloil.com/en/article/why-the-mobil-advantage/automakers-trust-mobil-1/corvette-recommended-oil

 

Quote

Mobil 1™ synthetic motor oil has been the factory fill and recommended service fill for Porsche engines since 1996. Current models include:

911

Boxster

Cayenne

Cayman

Macan

Panamera

Spyder

https://mobiloil.com/en/article/why-the-mobil-advantage/automakers-trust-mobil-1/porsche-recommended-oil

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On 4/23/2017 at 1:47 AM, Spyvsspy said:

Did you rehone the cylinder before installing the new piston and ring?  You have to have the cylinder walls cross hatched in order for the ring to wear in and properly seal with the cylinder

hmm no.. just asking, do you rehone cylinders that are nikasil coated??

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14 minutes ago, soheil said:

hmm no.. just asking, do you rehone cylinders that are nikasil coated??

A full re-hone...normally no.  Any Nikasil coated cylinder I've had off still had they crosshatch in place, it's extrememly strong and you will need a diamond hone to get any crosshatching back into the cylinder.  But due to the coating being so thin you run the risk of removing it by honing it yourself unless you've honed cylinders before. Rotation speed and stroke rate are extremely important.

That said, I have "scuffed" OEM nikasil cylinders to knock off any build up or glazing that may have built up in the cylinder walls, anything other than a diamond hone won't touch nikasil, that is as long as the cylinder is in good shape and not scuffed from a broken ring/piston.  Also look to make sure there's no ridge on the top of the cylinder where the rings seal the combustion chamber at TDC. 

Full synthetic fill after a rebuild isn't the best idea and doesn't let the moving parts "seat in" to each other. Yes some OEM's are "factory fill" with synthetic but many of those engines are run up on a dyno at the factory before it's put into the vehicle for the end user.  They are also built to a much higher tolerance than a DRZ thumper...

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I've rehoned with a flapper wheel to clean off any glaze.  My uncle owns an engine rebuild and machine shop.  If you don't have access to a cylinder flapper wheel, just use scotch brite pad and solution...I didn't see the part where your cylinder was nikasil coated.  

Edited by Spyvsspy
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ok everyone, thanks for all your suggestions!! :worthy:

 

since i changed the oil to non-synthetic it started fixing my problems!! before with the synthetic oil the pipe was pinch black inside, when i rubbed my finger in there i used to get a black oily powder plus the smell of burned oil when the engine was hot.. but now with the non-synthetic oil after 600km the pipe is just dry black nothing comes out anymore and no more weird smells, its just the usuall smell of gas ? 

if im not wrong i think i got some more hp here :ride:

thanks again everyone!!:cheers:

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