Ive got a 185 honda problem.....

[hotroddal]

ok here is my problem, i ordered a brand new piston and rings for my 1983 honda 185, and when i whent to install the piston and rings in the cylender, i noticed i barely had to squeez the rings together, so then i wanted to make sure it was a 185 piston and i measured it against the piston that i took out and it is smaller than that one so , then i whent and measured the piston that i toook out originally against a stock 200 honda piston and it is the same size.so ive cam to the conlusion that i have a 185 honda that is bored out to a stock 200c and it has a 200cc pison in it, and i have the correct brand new 185 honda piston and rings, so i am foced to buy a 200c honda piston and rings, so can a 185cc be bored out to a 200cc???

[83185s]

yes..the 185-200cc engines can be bored up to 67mm..the farthest that a 200x can go without a new cylinder..you can get it bored..if i was u id buy a 185 cylinder of ebay..there cheap ...and most on there are stock

[hotroddal]

so your saying i most likely have a 185 cylender bored to 200cc with a 200cc piston and rings?, and that i have boughten the wrong brand dew piston and rings???

[TimSr]

Judging from the Wiseco website, the 185 is a 200S with a very thick sleeve. It lists the first overbore as 2.00mm instead of the typical .25mm. This is also the Standard bore listed for the 200S, and they use the same replacement piston.
The first thing to do when replacing a piston is to clean off the top of it until you can read what is stamped on the top of it, to identify what piston is. Wiseco pistons are marked underneath with a circled "W" insignea on the underside. On the top of the piston both OEM and Wiseco mark their pistons with an overbore size, and/or part number.

[OldSchoolin86]

I'd like to add that if your installing a new piston you really should have measured it, oredered the right piston, and spent the $60 to have it bored to a new piston size.

[hotroddal]

well, on either of the pistons is any marks, except for the top where it says "IN" and that faces the intake valve port,other than that there are no other marks.

[TimSr]

If its says "IN" on the top it is not a Wiseco piston. Does it have any markings on the underside? I also agree with OS, you should have the bore measured to see if it needs bored. If its worn eggshaped, you cannot tell by looking at it.

[jeswinehart]

or you might have a 200 top end on the trike.
at the base of the jug ,,, what are the numbers stamped on it ???


john

[grundlegrabber]

You most likely have a stock, standard bore piston if it's stamped IN and no other markings. Someone probably installed a 200 top end on the bike. Cylinder should be measured with a micrometer to see if it's within specs for the bore it's on now. Those specs are available in the service manual. If it shows wear or is out of spec, it needs an overbore. If you are not going to bore it, it should at least be honed before installing a new piston. So there you have it- measure the cylinder (a machine shop can do this if you don't have the tools), determine if an overbore is needed, obtain the correct piston. And be sure to adjust the valve clearances properly. =:)

[hotroddal]

ok guys i have found out that someone in the past has bored the cylinder out to a 200cc and has instaled a 200cc piston and rings , and at the bottom of the cylinder it says 180cm3 so i know it is a 185 head that is bored to 200, so instead of using the bored cylinder, i just decided to use all 200cc parts that i have, cam,rockers,valves,piston,head,jug,tranny,cam chain, and cdi, all of this is within factory honda specs, i do have 2 micrometers, and i have used them to find out if these parts were in specs and they are, so i will be using evrything that is stock 200cc, so all i need to buy is honda 200cc piston rings, cuz i dont have those, the reason i originally didnt use the micrometers to see if the new piston is right is beacuase i never new it had been bored, and the the piston is for a 185 honda, so now i got all the questions answered, i whent ahed and ordered 1983 honda 200c piston rings, and so far today i have laped the valves and installed new valve guids and seals,and split the tranny cases and installed new gaskets and seals,and honed the cylinder, so all im waiting for is the piston rings and i can install all my new parts.

[HaggLE]

Its like the old saying: measure twice, cut one. But in this case its measure twice order once, not other way around. :)