Hemi build started

O

OUTLAWD

Member
#81
#81
Had a chance to test the new carb?

Ironically enough, I am having a similar issue with my Hemi with a OKO 24mm flatslide.

Starts no issue, part throttle is crisp and pulls strong, but at 4000rpm above ~1/2 throttle, it seems to just choke and die. This is the first time without having a Gov, so uncharted territory for me.

I thought it was a fuel issue, so I mounted a plastic tank on the frame, to ensure I had good feed, but it is doing the same thing.
 
noseoil

noseoil

Active Member
#82
#82
The new carb is fine & much better. I still need to do some tuning, but it's good with the vm22-133 carb. I'm running with a 30 pilot & drilled-out main at #46 bit for now (about .080"). Have other jets ordered, but they aren't here yet so I'm waiting to finish with the carb.

RPM is not the issue with a slide carb, it's only the throttle position that determines the fuel/air mixture & feed. I'm beginning to wonder if they used the right jet needle at the factory when the old carb was built. It acts like it completely plugs up the main jet once it gets past the idle circuit...
 
M

moetrout

Active Member
#83
#83
Can you change the position of the needle clip on that carb? In my experience mid throttle is controlled by the needle position. If you do have a needle clip move it down one position and see how it reacts. Also, I had a case with my street bike where it sputtered at mid throttle and found out my air intake was too restrictive. Opened it up and the sputter was gone. You could just try removing your air cleaner to see what happens. Get it figured out......we're racing on Saturday!
 
noseoil

noseoil

Active Member
#86
#86
Buy the carb! It's 100% better than the smaller vm22. The jets are on a slow boat from China & will be here sooner or later, so I swapped motors again back to the old mod1 for a ride up in Phoenix tomorrow. Will post once I get it back on something & re-jet to run better. Still pulls really well.
 
noseoil

noseoil

Active Member
#87
#87
Just a belated follow-up for the build, it works! I was way too rich with the jetting I wrote about. Pretty much settled on a 130 jet for now. It's too lean when the filter vibrates off, but that would be a good starting point for anyone running this carb on a built motor. My first choice would have been good for an alcohol motor (?) but really bad for gasoline. Bogging badly & way too rich.

Still running about 98 octane, since I don't want it to ping at higher rpms.

Did the "Hood Ride" yesterday up in Phoenix, great bunch of guys & a nice time in 75 degree weather. There were a lot of bikes, not sure, but most likely about 50 of then in various shapes, sizes & flavors. Props to Phoenix police department. They ran us out of a business park due to a rent-a-cop call, but left us alone on the ride & were pretty cool. That, or they didn't want to do that much paper work on a Sunday afternoon...

I did a couple of drags & it ran well enough. Ended up pulling away on both heats & on the second one, I ran it up to 8400 rpm before shutting it down. I'm really happy with this combination for a hemi motor. No reliability issues with it, other than it's a bit hard to start when
hot & a nasty kicker when I don't catch it sleeping, but it's a fun ride now.

Will pull it apart at some point, now that it's been run in for a while, just to check the guts. Will also need to go to SS valves if I keep turning that many r's or it will snap & eat a valve sooner or later. Still a little bit worried about the crankshaft being out of round, but it runs OK for now this way & pulls hard at WOT.
 
H

Havasu Dave

Moderator
#88
#88
Good to hear! I hope you get to enjoy it and win some more drag races before tearing it apart to inspect. You know what they say, "if it aint broke, don't fix it." :thumbsup:
 
You must log in or register to reply here.
Top