rebuild problem

[ski4]

Just finishing up a crank up rebuild, assembled the cases, all went smooth, put on the pistons and base gasket and cyl, and still all is smooth, went to top it off and put on the head, but now not so good.

when i turn the coupler the pistons are hitting something, that soemthing has to be the domes in my head both front and back pistons

the head has all new orings, it is a cool head
if i take it off all turns smooth, the head worked before the rebuild. if i take out the domes and hold them above the cyl by hand no hang ups either
i am now on 82.5 mm bores in a 701

looking at ada site, i am guessing these domes should work with these pistons (ada seemsto be good through 83 mm)
what else could it be?
base gasket? rods too long ( it is a brand new hot rods crank from paul at jr magooo's) :17:

 

[sprocketq]

sounds like youve got a thin base gasket? is it oem or a aftermarket one?

 

[madoyster]

Sounds like you just need to give Paul a call. He has great customer service.

 

[ski4]

that was one of my thoughts about the base gasket, it is aftermarket, (jetlyne)
i got it from paul actually, i have a stock one i was gonna hang onto as a spare ,hate to waste it if it is not though

mayby i will have to call paul
has anyone ran a prodesign head with pistons 82.5 mm

 

[ski4]

OK here is the problem, the cyl has been decked in the past, compared it to a known stock one and it is thinner on top by the amt the pistons come out of the bore, now what, is just a thicker base gasket the key?

i took a 2nd base gasket and put it next to the piston at tdc and it is flush with the rim of the piston now

so i am guessing the amt of material removed is the thinckness of a stock gasket

can i just put 2 in there and crank em down? can i get an oversized one?

 

[waterfreak]

First of all, you should check your squish clearance. Using a piece of sodder, stick it in thru the spark plug hole and turn the motor over by hand. Then, pull the sodder out and check it with a micrometer . If you are looking for bottom end punch for freestyle ,then you want to be between .035 to .050 clearance.

Adding another base gasket is just a bandaid. you will end up raising your port height and lose some bottom end. The proper thing would be to machine the inside of the domes. That's why you need to know your squish clearance first. I believe a stock base gasket is about .020 thick (correct me if I'm wrong Paul!) Also, make sure you measure the out diameter of your domes to see if it will accomodate the 82.5 pistons. It should be at least 1mm bigger then the pistons.

good luck!

 

[ski4]

thanks good info, i dont think there is any clearance now though as the pistons are actually hitting the domes i think it would just stop my rotation a hair earlier putting in the solder

who can machine the domes? any recommendations?

 

[waterfreak]

anybody that has a lathe. I think that Paul may be able to help with that. You will need to fing out how much to take out of the domes before doing anything else. Where did you get this cylinder and why is it decked so much?

 

[ski4]

it came on the ski when i bought it, no idea why he decked it so much

that is only one a a WHOLE BUNCH of things i am wondering why the hell it was done that way

needless to say i got blindsided on this ski
makes me nervous abou the porting work done on it now.

at least once it's done it will be done right

Paul, HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
you have seen these cylinders before ( or so the guys says) you did the last bore job on it so i hope the porting is ok , how about these domes?

 

[steve802cc]

Man that sucks, it just keeps getting better and better with that ski:17: .

ken_mueller82 :tool: (Pwctoday) must have got some flunky to deck the cylinder. Your average aftermarket head runs aprox 0.050" squish clearance. If he were decking the cylinder to make sure it was flat I can't see him needing to take off 0.050"+.
0.010" to 0.020" maybe.

I'd give Paul a call tomorrow when he gets back from skiing. Then you know it will get done correct.

Steve

 

[MADMAT]

ken_mueller82 :tool:
Steve

His name needs to be in the bad seller area here as well. :rocketwhore:

 

[ski4]

f'n ken, i have the paper to file a law suit against his ass sitting rigt here, the only bummer is i would have to go to clinton iowa to follow through withteh damn thing tehn if i lost i am out more, although i doubt i would loose but still time spent and time off work etc,
i would just love to pound that little sh&t into the dirt and then suck him back out refine him and run him through this ski once it is all dialed in

i have no idea why the little douche would have decked so much off, but like everything else he did to this ski
who the f knows

all i can say is thank god i cross threaded the coupler putting it on to find out this was a problem know and not on the water

this is what i am working with

 

[ski4]

spoke to paul this morning
there are a few possible fixes for this
i need to get him a few measurements and he'll give me the skinny on this

could just get a thick base gasket if all the #'s crunch out the right way



:hail:

 

[ski4]

well after measuring many things ends up, 0.050's were decked off this top end.
could get by with a thicker base gasket paul says , but then i would get a soft bottom end.
soo, some domes are getting milled and he says that should keep my low end tough and get me dialed right in with pistons not hitting the head.

thanks paul

 

[Frosty]

Glad to hear Paul was able to help you out bro... he rocks:hail:

 

[steve802cc]

some domes are getting milled and he says that should keep my low end tough and get me dialed right in with pistons not hitting the head.

Good choice. Thats the best solution. You've got it apart might as well fix it right.
Steve

 

[djkorn1]

Thats cool. Don't worry, the water is still 35 degrees and the beach is full of dead fish. We're not riding for at least a month.

DJ

 

[ski4]

yeah dj but after being in st thomas and st marteen and florida i am ready to ride RIGHT NOW

 

[djkorn1]

shoooooooooot. How was the trip..?? You should've rode with the X-Slide team in St. Marteen. Really cool people. I met them in Daytona.

Todays Lake Erie Water Temp: 35 degrees:frown:

 

[ski4]

i saw 2 stand up 's there with stickers of that there, i was hoping to rent them cuz they were beached at the rental spot
but no dice