252wheelieking

what elevation are you at using 19cc domes & +7 timing on a cub with av gas?

So far it's me, wifey, my two sons, jeff, dre & his wifey, cousin in law (maybe), shawn, jason & wallace. maybe more, you know we come deep.

How much compression & timing can AV gas support before detonating?

Im currently in the same situation & would like to know a positive answer to this. I am at sea level with 22cc cub domes & wanted to know where my compression should range & a safe timing to run with these domes? Thanks

I am building a 4mil cub duner & wanted some opinions on what parts I should buy to make this a nice duner. I mostly ride wide open fields, paths & backroads where I live. The only parts I have brought are Hot Rods 4mm crank, 421 cub & 22cc domes. I had plan on using the bolt-on parts from my stock cylinder engine with this 421 cub duner build. I already have VF-2's, SB IF Shearers, Chariot Coolhead, advance timing plate, Boss Racing intake, 34mm PJ's, K&N filter pods, Driveline clutch kit, modded shift star, & shift pro kit. This is my first time setting up a cub mono block, so all help is needed including fuel & timing for this set-up. I know I need a billet basket, billet impeller & 68mm blaster pistons, are there any other parts needed or parts that you guys would replace to make this a better 421 duner? Thanks in advance Reek

I had a HJR stock stroke dune port & you will beat the shit out of him even if you didnt know how to ride your shee that good.

PM Sent

I asked this question also & didnt get an answer. PM SENT

I agree^^^....Jetting on the main should start around 165 IMO. check compession, fuel, timing & air fuel screws....just some things to look at off the top of my head.

Mines are on the backside of the cases near the #15 bolt on the upper case. Right below that on the lower case are the same markings . Looks like someone ingrave them by hand with a tool or something.

I dont know a cameron sawyer....not fully understanding what you mean....Are you saying i should let him dyno tune it or did i let him dyno tune it?

I will....yes, it's easy.... I built my complete bike from the frame up.

I cleaned the cases & they are matching cases. both cases have X9 142 on the upper & lower cases. I am leaning more towards something is out of spec. with the cases. I'm going to buy another set of cases & rebuild it again except im going 4mil cub this time.

This is the second time that this has happen to my engine. I brought a good OEM crank inspected from a site sponsor. Had a fresh bore & hone with new pistons from site sponsor. I followed the directions from the cylmers manual to build the engine & did leakdown test & squish test. The engine passed the leakdown test but it loss 1 psi. in 6 mins. which is acceptable. What could be causing the thrust washer to shatter like this? can anybody give me some pointers on how to prevent this or what is causing this? what am I not doing correctly?

Here are some pics of the right cylinder: Here is the left cylinder:

I dont know if these are non matching cases or not. I brought the bottomend from somebody else.

Well I pull my clutch cover off today & the water pump & impeller is working just fine. So I pulled my cylinders off & inspected the connecting rods to find that the samething happen to this crank that happen to my last crank. The right side lower connecting rod thrust washer shattered & came through the transfers & ruin the top end on the right side again. The left cylinder stills look good, but the right cylinder is totally ruin. What could be causing the thrust washer to keep shattering like this. Im thinking about just buying another set of cases & rebuilding it over. I feel like im having bad luck from these cases, cause I built my cousin & my cousin friend motor & their motors are still running strong with no problem. Will non matching cases cause this? I followed every step detail by detail to building this motor to be reliable. Here are some pics of the crank where it let go in the same spot again. HELP PLEASE......

X2...

Is this the same motor 4milldragshee built?

thanks for the heads up...i hope it doesnt change, if so only for the better.

What wrong with that...I dont either or have license. but my bike & i seems to make it anywhere there is a ride.... Seriously borrow a trailer or truck & go down there one weekend & you will see that you dont needs friends to go to busco cause you will make them while your there. if you have a little bit of communication skills. that's how i became friends with surfrjag, mmjay, & alot more that im not going to type cause it's too much....excuse me cause im feeling this crown royal right now....

Do you acutally know what you are missing out on. get out there ride & meet new people. it the best place in NC to me.

just curious...how often should you do a leakdown test on your motor? just to prevent from a meltdown in the future.