collapse

www.dimecitycycles.com


www.restocycle.com

www.CITYLIMITMOTO.com

www.jadusmotorcycleparts.com

www.bisonmotorsports.com

www.speedmotoco.com

www.cognitomoto.com

www.townmoto.com

www.sparckmoto.com

www.Moto-Madness.com

www.pistonsociety.com

www.steeltowngarage.com

QUESTIONS ABOUT THE SITE? TROUBLE REGISTERING? ADMIN@DOTHETON.COM

Author Topic: Yamaha SR250 Power and Temperature Testing  (Read 16871 times)

Offline sbruton

  • DTT SUPPORTER
  • *
  • Posts: 320
  • Where the fvck is that money you owe me?!?
Re: Yamaha SR250 Power and Temperature Testing
« Reply #90 on: Nov 30, 2016, 22:07:51 »
Badass.  As an engineer, I totally dig the thought process and mechanics of your testing procedures.  It will be very cool to analyze the results once you've had a chance to put your theories to test!

Offline JadusMotorcycleParts

  • DTT SUPPORTER
  • *
  • Posts: 782
    • Jadus Motorcycle Parts
Re: Yamaha SR250 Power and Temperature Testing
« Reply #91 on: Jan 11, 2017, 16:19:12 »
The exhaust thread in the head of the Jadus Test Mule 1.0 finally gave out  :(  Swapping headers around and bolting down the clamp flange a few times did it.  If you look closely at the hole you can see the old bolt is actually still there - in the middle of where the new thread should have gone.  But sadly, the muppet that did this repair job failed to extract it and then just decided that a new M6 tapped hole, 3mm to the right at a 15 degree wrong angle was good enough.  Same person that bolted in a wood screw remember!  Gah. 

I took it as a sign.  I am going to do a full rebuild of this engine eventually and make a separate build thread of it.  I'll get that exhaust thread repaired properly with the head off - hopefully even welded up and re-tapped in the correct position.  I have lots of ideas for the build... Cam, high comp piston etc.  It's gonna be a killer.

In the mean time, plans go ahead to complete the testing on the Jadus Test Mule 2.0  ;D

Offline Tune-A-Fish©

  • DTT SUPPORTER
  • *
  • Posts: 6835
  • BOTM LOSER Proudly Deplorable
Re: Yamaha SR250 Power and Temperature Testing
« Reply #92 on: Jan 11, 2017, 17:14:49 »
If you made a drill jig to bolt to the other hole and went slow you could get a timesert in that head.


Sent from my iPhone using DO THE TON
"I didn't come here and I ain't leavin"  Willie Nelson

"love hard, live fast, die fun" Kacey Musgraves

"Like a Wreckin Ball!" Eric Church

Offline JadusMotorcycleParts

  • DTT SUPPORTER
  • *
  • Posts: 782
    • Jadus Motorcycle Parts
Re: Yamaha SR250 Power and Temperature Testing
« Reply #93 on: Jan 12, 2017, 15:35:31 »
If you made a drill jig to bolt to the other hole and went slow you could get a timesert in that head.

That was my original thought too, but unfortunately, the new threaded hole is so far off centred and crooked that it has removed a lot of meat where the timesert would nead to go  :-\  So I think I will extract the bolt that is there and try have it welded up - def a job for a pro.  The jig is an awesome idea for the new hole though.

Btw, pros and cons for Timesert vs Helicoil?  I have used both and didn't quite evaluate if one was better than the other  :o

Offline Tune-A-Fish©

  • DTT SUPPORTER
  • *
  • Posts: 6835
  • BOTM LOSER Proudly Deplorable
Re: Yamaha SR250 Power and Temperature Testing
« Reply #94 on: Jan 12, 2017, 16:23:14 »
Helicoil is like a thread spring, sub par but will work. Timesert is a solid part and installed with a roll form tap that sets the od threads in the tapped hole with a shoulder to both stop it and provide a perfect opening for alignment.

I got a set that provides a four step process... drill, shoulder cut, tap and driver/thread roller.

Really better than new if installed in aluminum.








Sent from my iPhone using DO THE TON
"I didn't come here and I ain't leavin"  Willie Nelson

"love hard, live fast, die fun" Kacey Musgraves

"Like a Wreckin Ball!" Eric Church

Offline JadusMotorcycleParts

  • DTT SUPPORTER
  • *
  • Posts: 782
    • Jadus Motorcycle Parts
Re: Yamaha SR250 Power and Temperature Testing
« Reply #95 on: Jan 13, 2017, 12:56:26 »
Ah sweet, that definitely looks like the way to go!  Have just read a bit more and it looks like these are the ticket for cylinder blocks and things too - perfect :)

Offline JadusMotorcycleParts

  • DTT SUPPORTER
  • *
  • Posts: 782
    • Jadus Motorcycle Parts
Re: Yamaha SR250 Power and Temperature Testing
« Reply #96 on: Jan 14, 2017, 05:37:53 »
One of my favourite shows on Youtube (after MCM and Roadkill ;D) Engine Masters have done some pretty awesome tests with exhaust systems - both collectors, inch size and mufflers.  Although slightly different, a lot of this stuff is applicable to bikes too.  I have been inspired by their methods and love their enthusiasm! 


Offline JadusMotorcycleParts

  • DTT SUPPORTER
  • *
  • Posts: 782
    • Jadus Motorcycle Parts
Re: Yamaha SR250 Power and Temperature Testing
« Reply #97 on: Mar 01, 2017, 16:27:12 »
Incase anyone missed it, here are what the cooling engine covers look like on the other Jadus bike...

I will continue to conduct testing on them as summer (e-ven-tu-al-ly) rolls around here in Sweden.  But the testing will be carried out on the orange Jadus test mule.  I will swap over the sump oil temp set up and the head temp set up, but probably won't bother with the oil galley set up.  Even though if I wanted to, I could just swap the whole engine case over ;)

Offline stroker crazy

  • DTT SUPPORTER
  • *
  • Posts: 3701
  • crazy as a fox
Re: Yamaha SR250 Power and Temperature Testing
« Reply #98 on: Mar 02, 2017, 01:02:49 »
Too many fins are never enough!

Crazy
“Ride like the Wind” W.H.

Offline JadusMotorcycleParts

  • DTT SUPPORTER
  • *
  • Posts: 782
    • Jadus Motorcycle Parts
Re: Yamaha SR250 Power and Temperature Testing
« Reply #99 on: Mar 25, 2017, 16:16:39 »
Here was the jetting options I accumulated leading up to the last dyno session, which happened around 4 weeks ago now.  I am going to add some pretty lengthy posts here summing it all up :)

I also decided to become a reseller for Keyster carb kits too, because they are amazing!  I ordered a couple sample kits and had the chance to test out the jets on the dyno day as well.  They are spot on.  The kit includes all the things that usually wear out or break on the SR250 carb.  But I think my favourite things included are the different jet needles.  What we found during both dyno sessions is that moving the needle clip position up and down does not very often put the mixture where you want it.  But with these different needle diameters, it really does wonders to evening out the air-fuel ratios :)