Built Predator 212 - WOT RPM expectations under load?

[GustoGuy]

force, I ran a 196cc greyhound in the pass with a mod2 . engine only had 25/24 valves with just porting in the bowls into the runners little. ss narrow stem valves,different piston,milled head. cc out to 11.5 compression and that too only ran a 120 jet. it seem to pull good up to 7000+ with 1.3 ratio rockers,billet rod,flywheel. I only use it for one drag race and one short summer on a fox bike. I now have been playing around with ohh Tecumseh's and last year motor had a 22mm with 142.5 jet and turn 8200 rpm's....fun
well my little greyhound is coming out of retirement and going on a rupp for a small circle track race. also have to change the suspension and rear tire...etc make this little guy turn left.....
it's no top fuel drag motor,but I aways like the way it ran. just a good strong motor....

Did you extend your rear swing arm? Looks like you stretched it at least 4 inches or so and placed the kickstand on the swing arm. How loud is that pipe since there doesn't appear to be a muffler on in?. I am looking for a rear fender for my Roadster 2 with the 12-inch wheels. Do you get sprayed by the rear tire when you ride in wet conditions since your not running a rear fender?

 

[force]

I believe I am running a 12.5 or 15 pilot with a 120 jet. if that helps little? been couples years when I first put that motor together and today I didn't even touch the carb. just bolted it back on with a new intake and fired it up.

So that means I already have a relatively big pilot jet in there, hmmmm… It idles fine and the plug looks good so probably nothing I need to worry about. Just gonna have to send it!

 

[delray]

Did you extend your rear swing arm? Looks like you stretched it at least 4 inches or so and placed the kickstand on the swing arm. How loud is that pipe since there doesn't appear to be a muffler on in?. I am looking for a rear fender for my Roadster 2 with the 12-inch wheels. Do you get sprayed by the rear tire when you ride in wet conditions since your not running a rear fender?

yes the rear control arm has been stretch about 5inch's.
the bike was really only build at first for a one off custom built hs-40 engine. here is the thread with the bike in it too.
https://www.oldminibikes.com/forum/index.php?threads/hs-40-build.161335/
bike was never design or made to ride in mud for my application. so I don't use the fenders.
bike is now getting converted to be use for a circle track race and installing the clone motor that I had to make a header for it. yes it's load and seems to work good for a non tuned header. maybe the curves in the tubing are helping....lol

 

[force]

UPDATE: after changing to the 146 gram weights and white springs, she now tops out at 5,890 RPM's under load and 53.1 MPH, with engagement just over 4K.

All in all, what I was hoping to get out of the build. Quite a handful to ride though lol.

I intend to drop back to the blue springs to lower engagement a bit, as it looks like Goma's Minibike Massacre isn't going to favor top end with the track layout this year.