cylinder identifacation

[barneypeter]

had a mare today went to fit new exhaust and threads went in exhaust side so stripped of f barrell to get it sorted so now its about time i found out what this beast is running.it has a alloy cylinder that has a bore of 65mm,has a pro port harry barlow manifold with reedvalve inside ,so any help with id would be good as i need a base gasket to suit and to know if it should run with a head gasket or not,i would post a photo but dont know how but could email it to some one ,also i presume its a 200 barrel can any one tell me the stud spacings of 200 and 150 please ,its a quick machine so would like to now how and why

[barneypeter]

forgot to mention that even though it is reed valve carb is still on the left ,not gt 186 as it is alloy barrell

[byron]

65mm wouldn't be a 200 barrel. stock "200" [nearer 198] cc are 66mm
could it be a bored out SR barrel ?
I had mine rebored to 66mm, so they can take 65mm, which would be about 192cc
is it a small block casing ? unlikely somebody would faff about making a 200 barrel fit on a 150 casing.
just get a standard 150 base gasket and cut it to fit around the bore and transfers.
MB, as probably others, do a 65mm head gasket

[barneypeter]

casings have been machined and welded around transfer area how much difference in stud spacing is between 150 and 200 cant work out how to post a pic ,could email it to you if you would look at may be you could id it also has locating dowels in the barrell which fit in to head cheers peter

[byron]

ok, just measured a 200 block across lower two stud centres - 65mm
and a 150 casing across the same was 63mm.
just using a steel rule, so a bit approx, but the difference was clear.
hth

[sean brady scooters]

whats stamped on casing........engine number prefix..?

[barneypeter]

sean casing is unstamped not ground out just unstamped ,scoured internet cant find head barrell or manifold that resembles it

[camel]

purchase a base gasket for a 150 and see if it fits..if it dosnt its a 200,notice your measuring things with a "steel rule"....how did you measure the bore?

[barneypeter]

right got a 200 and 150 base gasket and its 150stud spacing but the transfer ports are two and a half the size of stock 150 the bore i measured with a set of vernier calipers ,thanks any ideason what kit it is would be good,doesnt seem to be one on the market ,now,has there ever been akit with ally clinder and reed valve on left hand side or is it homebrew

[camel]

im wondering if its a challenger kit from the 80,s..harry barlow/chiselspeed made them in limited quantities,i had a bike a couple of yrs ago with one one,it was on a 150 casing,using a 205 honda piston,anyway...if you can get pics on somehow im sure we,ll have a better idea