Urgent Help!!!

i just installed my ada headkit and the piston pin i got is smaller than the stock one. i put the stock piton on w/ the headkit and the piston hits the head wen it turns. can i put a smaller pin bearing on the crank or do i have to get a different crank?

If the stock piston hits the top of the new head then add another base gasket or two. This will actually work to your advantage.

I'm having trouble understanding what the problem is. I believe they make a 10mm and a 12mm pin,and bearings for each. Are you saying you used a 10mm pin with a 12mm bearing? Is everything else stock? Did you use all gaskets?

i used the base gasket and the one for the dome. i used the stock piston tho b'cuz the one that came w/ the headkit has a smaller pin and the stock bearing is bigger im guessing the stock one is 12mm and the headkit one is 10mm. So do i have to get a bushing that fits that pin or would i have to get a new crank?

snm1 is correct.
When the piston hit the head during the mock install a big should have come across your face.
You now have more room to alter your port timing and squish.

if you dont have another base gasket go to pepboys and buy some gasket paper. I cut all of my own gaskets. Just trace the original and cut with an exacto knife. They make different thickness of the gasket paper and you can get your squish in the .8mm range. I have found that .8mm is what works the best on my engines.

so i should just add gaskets? but would the head be unbalanced due to the gaskets or would it sit fine? i didnt ven check the squish cuz i couldnt get a caliper to measure the squish, it's like 40bux. anyway...i was thinking of adding the stock gasket but the head's got boost ports so i gotta do the cutout for it on the stock gasket...good idea or no?

Looks like you ordered the wrong kit.
From this post it sounds like you have a stock BB which means your pin is 12mm.
The kit you purchased has a 44mm piston with a 10mm pin.
You can use your stock piston and pin you just need to use 2-3 base gaskets and lower the floor of the exhaust a tad.

I think you would need to buy a new crank. Is the center of the piston pin to the top of the piston the same height on both pistons? I'm wondering if the head kit piston is different? If not you should be fine,make sure you use new rings. And like the other guys said throw 1-2 base gaskets in there and play with it till it feels good,wouldn't hurt to play it safe with more gaskets.

You can use stock gaskets.
Just trim out the area for the boost ports.

BTW....Harbor Freight has the digital calipers for @ 25.00.

I run two gaskets and a 1.5mm aluminum spacer that shims up the cylinder almost 2mm, you will be fine. No need in cutting the gasket for the boost ports. I have single , double boost ported cylinders and never trimmed the gaskets since the gasket does not even come close to the boost ports.

Nah...no need for a new crank.
His stock piston and pin will work fine.
I am running the ADA 44mm boost ported heads with a stock BB crank.
He actually has an advantage cause he gets to raise his transfers.

Was refering as opposed to buying just a bearing for the rod. I've been out of the loop for awhile. Would that throw the balance off at all by running a 44mm on 40mm crank and rod?

This is correct 110% plus some....

The ADA boost ported cylinder does protrude into the base so he will need to trim the gasket accordingly.
When I first installed mine I couldn't figure out why I had a fuel mist coming out of my carb in the upper rpms.
Pulled the head and noticed a dent in the gasket where the boost port was.
Trimmed the gasket away and problem solved.

Nope......
Most if not all of the BBK at the beginning was set-up this way.
Remember the pin caps that came with the kits that were used to make the 10mm pin fit the 44mm pistons?

never knew this forum could be so much help...thanx guys!! i added the stock gasket and it still nips the dome a little bit but it turns fine. im gonna go tomorrow and buy a couple of gaskets since i already put gasket sealer on these so i dont think they'll be too good to use. i guess i'll buy 4 and try out the squish w/ 3. btw...the motor is an ada racing 47cc that comes w/ a 44mm "big bore kit" but it's got no boost ports or anything. the kit i got is a 44mm headkit w/ a billet headshell and 13:1 dome and the piston that came w/ it is a little shorter than the one that came w/ the motor so therefor i have to lift the head a little bit. i'm gonna see if i can borrow the caliper b'cuz i have friends that work at discount auto parts and they hook me up =D.

Kinda ,I'm still back in the time of boost ported 40mm's,and people were just starting to play with the 44mm's,head kits are all new to me.

i just recently got into pocket bikes. i bought mine off a friend for 100bux about a month ago or a little more and i knew nothing about them. i learned a lot from PBP.

They are addicting little things