Nyroc on your site you talk about "A performance exhuast and milling the head to raise the compression ratio to 8 to 1 would probably help a lot. " on suzuki jr 50s. My question is how much do you mill off for 8 to 1 compression, or how much do you mill for 8.5 to 1? (or is that too much?)


thanks
Chuckzie

 

I haven't had the head off yet to see what can be done. Basically, you need to measure the combustion chamber volume (also include any deck or dished piston). Then backward calculate what combustion chamber volume would be required for 8:1. See how much head milling is necessary for this. Might even need to be filled - who knows.

Mike Penland suggested filing the exhaust port do it is 1mm closer to the head to give it more low end torque.

I hate the 50. It gets stuck on hills. It is really only made for babies.

 

Just a idea, but would alcohol conversion help this problem?

I thought about going to a lower gear ratio.


thanks Nyroc for your help


chuck

 

With the compression ratio at 5.9, I would think raising it to 8 would work wonders. I would do that first before anything.

I don't own the 50, my brother does. He is as poor as a church mouse at the moment and he won't touch it.

Selling it and getting an 80 is the fix I think will work best.

 

Get the kid an LT 80 if he can handle it. Way more power; a better machine all around.

 

Nyroc

I went ahead and milled the head to 40 thousands. I could have went too 50 or 60 without any clearance problems, but I was not sure what the compression would be. History with cars has told me (rule of thumb) .5 to 1 for every 10 thousands milled. I'm not sure if that is correct for little 50's though. If so the compression would be around 8 to 1.

Will it helped the bottom end a little, but mid and top range is a big increase. Not sure how much yet but in the morning I will clock the new top speed with my 650. So far I have gutted the exhaust (not loud/ chain saw loud), uncorked intake, messaged the needle jet (honed a new shape) and moved it too the bottom notch, removed the little air box and replaced it with a custom made snorkle with a K&N crankcase filter for a V8, and removed the small pilot jet. I havent tried a 70 main jet yet, but in the plan. Dont get me wrong it is a big difference, I just havent been able to do some real world test yet with my son (only test is to try a stop on a hill with my 200lb butt and get going again). If the top speed is a good increase I will change gear ratios that will greatly increase hill pulling power.


[img]i/expressions/face-icon-small-happy.gif[/img] FYI thought you would like to know.

thanks
Chuck

Oh by the way, the thing start alot Better and sound like a CR 60![img]i/expressions/face-icon-small-tongue.gif[/img]

 

Oh Novia

My boy just turn 5 he has had this 50 for a year. Mostly burning up the yard, now I won't him to ride the trails with me. I will mod this machine because it fits him will in size, but he will get a KX 60 next year for his birthday, and the following year a Lt 80 like yours. Then a JR dragster, and then KX 80, and a Oh My fault, I'm forgeting my daugther's rides! Will you know, I wont them to be the next Earnhart's [img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-tongue.gif[/img][img]i/expressions/face-icon-small-cool.gif[/img]!

thanks Chuck

God I love being a Motorhead Daddy![img]i/expressions/face-icon-small-wink.gif[/img]