torquing cylinder base nuts....

stainlesscycle

stainlesscycle

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welp, we all know the cylinder base nuts in the front are a bitch to torque - i use a box end wrench that i've ground way down and just pull till they're really tight. is there a better method? - i thought i could get a crows foot with a torque wrench in there, but there's just no way..

i noticed there's some oil migrating on the old gasket around the 2 front studs, which tells me i didn't torque enough last time i was in there..(or not clean or not flat....) - book says 25Nm which i convert to 20ft-lbs - doesn't seem that tight..


also anyone run no gasket? i was running .3 gasket, and had 2.0 squish. sent head to rb, and he said no go on the head mod (i have 15 degree plug hole..). if i go to to .15 gasket it'll bring squish to 1.85. if i run no gasket, (and just hylomar..) i think i can get close to .03 thickness (according to hylomar site.....) makes 1.72 squish.. - i've used hylomar on 4t's for base gasket and it's worked amazingly well, but i think 4t base gaskets see at lot less heat/pressure than a 2t..... i know all this will change my port height, which i'm cool with, more low end is always nice on a 200..
 
I cut a 13mm box-end wrench and welded it to a socket and use that with my torque wrench.
 
I use a KTM bottle opener which is really a cylinder nut wrench (13mm) made to go on a torque wrench as an extender. You could pick one up for a couple bucks because everyone thinks it's a bottle opener.
 
Adapters don't give very accurate reading as it changes the distance. You are actually not even supposed to use extensions on torque wrenches. I just try and tighten them all pretty much the same and let it go and have never had a problem. I am much more particular on my heads however. The best thing you could do is get a 12 point wrench that you could drill a hole 12" from the center of the box end. Take a spring scale and and put it through the hole and pull until you get the reading you want. That's where ft/lbs comes from.

I tried using permatex as a base gasket once on my Gasser but it didn't hold for long. I had used it on a CR250 (2t) years ago and it worked, but only lasted 4-6 hours on the GG.
 
welp, i got the squish to 1.75 with the .15 base gasket. haven't checked compression yet, and it'll probably get a tiny bit tighter when i actually torque the head..
 
iirc ....
i used a regular 13mm open end and box end wrench. One end fit over the nut the other end fit the square thingy on my 1/2 drivew craftsman torque wrench. I think i had to grind the open end a bit to get it to fit. Motion pro has a chart thing you can down load to figure the extension effect.
 
Similar situation with the head nuts on Ducati motors and what I've been told is: If you increase length on the lever arm/torque wrench with an extension you have to correct for that. But, if you mount the extension at a 90 degree angle to the torque wrench no correction is needed because you have not increased the length at which you are applying torque. I haven't actually tested it with a scale, but I know that's the way it's commonly done on the Ducs and it's the way I do it on my GG. I ground down a 13mm box end and welded a socket to one end so it would mount at 90 degrees.
 
The best way to think of it is if you are extending the length of the handle away from what you are torqueing then you have to change the torque. I you are not like a socket with a long extension(height) then you don't have to change it because the handle you are pulling on is the same lenght away from the nut.
 
The low cost option would be to torque them down to "about right".

Using a regular spanner, being patient and going in a criss-cross pattern, they can be tightened using the same strength as a regular 12mm/13mm hex, not more. Don't get carried away and give it more "just to be safe, and then some more".

4-strokes, yes, they are critical and you can actually get access to using a torque wrench where neede, but this is the joy of 2-strokes in that it is not rocket science and special tools are not really needed.

Also, a mistake with these machines is not $2000.

Later, F
 
I had RandB do the head on one of my bikes. I switched piston brands when I put it back together and the compression distance was different. I removed .5 base gasket and run only the .3 gasket. I hate the way it runs. It has way to much off idle snap. If the power came on 500 rpm later it would be fine. I think the added head work and dropping the port timing has did some evil to this bike and it is something to think about. All things being the same I going to put the .5 base gasket back in the mix. It sounds strange to much power, but it is in a bad spot. It hurts people in the woods.
 
too much juice in the wrong spot sucks!!
have you tried some taller gearing. maybe the extra get up and go will pull taller gearing and not be so snappy??
 
You can run a gear high and its still bad. I like it on the mx track. I think if we put ktm suspension on it we could use it to do away with the prison system. We could just sentence people to do laps on it. After their arms had been yanked out of their sockets countless times and they hit every other tree on the course they might opt for lethal injection. I have yet to have anyone ride it in the woods and like it. It does rip! I do wander if pulling out some ignition timing would help.
 
Yeah I hate too much yank off idle, thats why the 250 is a nice bike for both trailriding and racing. Adrian you have been around for a long time, I'm sure you tried retarding the timing and/or adding a reed spacer, did either help? Maybe some fine jetting changes down low as head work makes them real crisp.
 
I've tried jetting and it does tune it out, but it loads up. It has the reed spacer. I should retard the timing. I'm torn between that and putting the base gaskets back to stock. It ran fine before. with four bikes it's just easier to ride a different bike so it don't see any love'n.
 
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