stroking

my threaded end is not as long as the plug on my gauge

im below sealevel in some area and 20ft above in others......both cylinders have the same comp so it can' be the rings.

i got a set of 68mm 18cc domes and the compression is now at 162psi,think i should have gotten 16 or 17cc domes. but the bike runs ALOT better now....just can't get it to shift under a load

this motor was bought like this,so i guess the seller just threw a head on there to make a quick sale

I POSTED UP A TOPIC ABOUT THE COMPRESSION on this motor [120psi] a while back and today i decided to take the head off to have a look at the setup....well the head is completely stock 64mm.. and i rechecked the squish and its .110 on left and .108 on right...wayyy to big for a alcohol motor i think..... i have a pic o how much needs to be cut out of this head to fit the cylinder.....oh and the piston was hitting the head on the very edge also.........good thing i tore it down to have a look.......why would someone put a stock..UNCUT head on cub cylinder i don't know.

NO i can't

I just put a motor together and now it won't shift pass 3rd under a load. is there a certain way that you are suppose to install the drum and linkage ?? should the drum be set in a certain gear when you install the shift shaft ?? its a 4mil cub motor with a lockup clutch.

well i know someone that runs +14 on a cub with over 200psi and it runs 6.20's all day long he even tried lowering the comp. and the bike ran 6.40's so i'd say that timing and compression is one of thos secrets builder won't tell you,or lie about telling you too much will hurt your topend,and thats just not true. hers is what you do,take your bike to a drag strip and try +5 +7 +10 and see how it runs if it does not get faster with more timing i'll send you a $100

squish is 0.050 if i can find 68mm 18/19cc dome that would help me out being that i have 2 cool heads i just found today hiding under some other parts. anyone got some domes for sale ?

squish is 0.050 if i can find 68mm 18/19cc dome that would help me out being that i have 2 cool heads i just found today hiding under some other parts. anyone got some domes for sale ?

HOTROD 4mil / 68mm bore motor i'll get the squish in the morning

its a customers bike and he's on a budget so the stock head what were using,i just need info on how much to cut.

is 120psi to low on a new cub topend with the stock head? should i shave down the head for more comp or just jack the timing up to 10-12 deg ? its a alcohol motor.

is 120psi to low on a new cub topend with the stock head? should i shave down the head for more comp or just jack the timing up to 10-12 deg ? its a alcohol motor.

i think thats all thats done to it....intake clean up i want this thing to run HARDDDD....so how can do the best work on cubs ? im looking for 6.20's or lower its a 4mil cub with 37mm carbs on alcohol,CPI drag pipes....think that will pull 6.20's ?

hey i got some cub cylinder for a good price and the guy said they are drag ported,can anyoneshow me a pic of cub cylinder that have been drag ported so i can see if i got the same thing.

head is cut to run a 4mil.....stock style gasket

does this look like it was caused by running to lean ? we have not found the cause yet. its a alcohol motor! how much oil do you need in alcohol ? i used 4oz. for every gallon but some say to use 6oz.

those piston came like that with the 4mil kit....not sure what kind they are,but if you buy a 4mil kit from motosport.com thats what comes with it.

Thats why some add another spark plug.......DS's come with two plugs from the factory

BINGO!!!

and those kind of raptors will eat up a 4mil stock cylinder or cub in 1/8mile....the power comes on STRONG,HARD,AND FAST on a well built 4 stroke! ive seen a 450 making a 72hp beat a 80+hp banshee,maybe in thesand going up a hill is different....we don't race like that...but flat hard pavement....you better be careful......alot of banshee guys get cocky and gives up 2-5 bike length head start thinking ...{its a 4stroke} so i know i can beat,and bam.....they get there azz handed to them........i love cocky banshee owners and the look on there face when they get beat. think of it like this,what if they build a TWIN 4STROKE 450......you can bet your house a banshee will get rolled on..

this crank is only 3 weeks old,lot of money wasted here.

the guy that was riding the banshee also did this to a yfz450 two hours earlier that day

I don't know what happen here,but he was at the light it turn green and he launch and went 12:00 when it came down it hit hard,he cruised down the track with a rattling motor.......and this is what i found ....note this engine would still start on first kick