I'm not a softy ... :-)

[JanBros]

I changed the title see second page 


... or is there somthing wrong ?

Seems I can't get my 500 engine kicked over 

Already installed a decompression valve : drilled a hole off 2.5mm from the head to a stud. If I kick it like this without the nut and valve on top, I manage to have it turned over - just-  but in no way it's as easy as can be seen on some video's where the guy just sits on the saddle while kicking it . The nut I made ( I have a lath and a mill) also has a 2.5mm hole, and with the nut installed it's the same.

Then when I put on the decompression valve (comes from a Still chainsaw) it's again like kicking a wall ... Is the opening in the valve too small ? I already drilled the outgoing hole also to 2.5mm, but don't know what's inside. Head looks completly syandard wihtout any other work done to it.

I measured the combustion chamber volume, and it's about 32.7ml or ccm . Is this normal, or is this very little ? only thing I did on to the head was take a bit off to get to a squish off 1.5mm (which is still ver safe I thinck ?). squish was over 2mm, I couldn't measure it with tin solder.

without the head on the cylinder, the top off the piston is even with the cylinder. is this normal, or has the cylinder been shortened ? it has a steel liner, so might be possible they skimmed it to get it even.

since my engine came out off a KX250 frame, I wondered if I have the right Kick ? so I measured it : from the bolt that holds the bearring-ball to keep the kick in place to the top is 18cm. is this correct, or does a 500 should have a longer one (which would make it easier) ?

cranck ran free when I putted it back in (with new seals and bearrings), without sparkplug no real resistance ...

At the moment I'm running out off ideas, other than I'm too soft for this engine 

Or do I just need a different decomp valve that lets escape more ?
What's the biggest hole you can drill through the combustion chamber without having problems ? I read on here most off you only drill a 2mm hole.

[Chod]

39.95 Jfab head ache gone.

[JanBros]

39.95 Jfab head ache gone.

in English ? 

forgot to mention : 32.7 is including the complete spark plug hole.

[Friar-Tuck]

 The Engine Builder/Machinist/ Fabricators have been very open with their work.  
   Hopefully some of them  will read this and post.
Everyone I have read who has the DeComp valve likes it as it is a marked improvement. Something doesn't sound right.
    Please stand by...
  Tuck\o/

[Friar-Tuck]

  He's referring to buying a kit supplied by one of the Fabricators on the site. He will send you a kit For about $40.00 US.
  I'm sure that does not include shipping Overseas to UK.  I will look for the post.
   Here    http://www.kxriders.com/forums/index.php/topic,6545.0.html

 And Chainsaw DeComp
Here: http://www.kxriders.com/forums/index.php/topic,6998.0.html

[Danger4u2]

Sometimes it can be something simple.  I installed  new clutch and ignition covers on my CR500. It's a bike I have never had a problem starting.  I kicked and kicked and could not start it.  I pulled the ignition cover and the flywheel weight was coming in contact with the cover.  I could not feel any difference at the kicker.  But it was just enough to take the oomph out of my kick.  Maybe it was grounding the bike out because the cover is now aluminum.  I took a die grinder to the inside of the cover where the flywheel weight scored it.  Reinstall, kick, remove, grind and repeat until it was clear.

Has it always been hard to start?  Try kicking it with the spark plug removed.  It should kick real easy.  If not something is wrong.
You'll just have to go thru the logical process.  Spark, fuel-air-oil mix, compression, timing..........

Could it be a steak and potato thing?  I'm 250 pounds.  Maybe you don't have the kick starting muscle at the waist line like some of us.

[JanBros]

Has it always been hard to start? 

Don't know, as it's the first time I want to start it. bought the engine a few years ago for a project, but it had to wait until another project was finished. engine was taken from a KX250frame and ran at the time.

 Try kicking it with the spark plug removed.  It should kick real easy.

it does. you can still feel little resistance as it has to squeeze the air through the spark plu hole, but one kicks makes it turn over a couple off times.

  If not something is wrong.
You'll just have to go thru the logical process.  Spark, fuel-air-oil mix, compression, timing..........

it's not that it won't start  (at least : I don't know if it will), I can't get it that far : set the piston just after TDC and give it my best shot, but seems I can't get it to turn 360?

Could it be a steak and potato thing?  I'm 250 pounds.  Maybe you don't have the kick starting muscle at the waist line like some of us.

had to run that through a unit converter  ? I'm only 154 for 1m80, so yes, I have no muscle-excess  . I'm changing the extended kick shaft again at the moment so it's stronger and I can really jump on the kick, and hope that will do the trick. Still planning on building an "engine-powered real-wheel -starter-thing" , but in case off emergency (little crash at the back off a circuit for example), I should be able to kick-start it .

[JanBros]

  He's referring to buying a kit supplied by one of the Fabricators on the site. He will send you a kit For about $40.00 US.
  I'm sure that does not include shipping Overseas to UK.  I will look for the post.
   Here    http://www.kxriders.com/forums/index.php/topic,6545.0.html

 And Chainsaw DeComp
Here: http://www.kxriders.com/forums/index.php/topic,6998.0.html

I already found those topics , read them and made one  :

[95formula847]

  He's referring to buying a kit supplied by one of the Fabricators on the site. He will send you a kit For about $40.00 US.
  I'm sure that does not include shipping Overseas to UK.  I will look for the post.
   Here    http://www.kxriders.com/forums/index.php/topic,6545.0.html

 And Chainsaw DeComp
Here: http://www.kxriders.com/forums/index.php/topic,6998.0.html

I already found those topics , read them and made one  :

What frame is that in the pics?

[JanBros]

What frame is that in the pics?

Kawasaki KR-1S, gonna be a track bike 

[Danger4u2]

Like this one?

[95formula847]

Thats pretty sweet! Whats the original motor in that bike?

[JanBros]

Thats pretty sweet! Whats the original motor in that bike?

250 paralel twin 2-stroke.

now I really don't mind talking about KR's, but in the mean time, could someone aswer my questions ? 

[Motorrad]

Here Is the specs on my head copy and paste from jfabs comp release post from Stewart. 
Hope it helps.

y"es ..thats your head,,,, looks better in person ,,i was pleased with how it has turned out just got done lapping head miked .912 thick and was 42 cc chamber volume  ..mikes .882  now from head  nut face to deck thats .030 of face has .040  step 86 mm dia 4 degree squish and re radiuse chamber and polish 13.5 to 1 compresion good  setup for top end and long rides"

[Motorrad]

Another from Stewart archives

I know for a fact he was running 15:1 then
so 35cc = 15:1. 


"am running a 35 cc cyl head volume  right now stock is 42 cc  i have tried down to 29 cc"