need a little info ....250R/300 big bore

[Jarrod]

I bought a 300 hondaline cylinder and head on flea bay of coarse with no piston....
I located a hondaline 300 ( 1.0 mm) last over bore piston,gaskets,wrist pin,etc
from a honda dealer in Iowa .The parts are on there way to me.
What I couldn't find is a set of rings for it.I have hand fitted rings for
my race car engines for years.....I figure I can find something that will work
just wanted some suggestions or ideas...
From looking at the parts fische at service honda I need a few more ods and ends
like the bigger main jet,etc...so here is what I need...

1-Piston rings (any suggestions 1.0 guess would make it a 310cc?)

2-hondaline 300 installation instructions (could some one pm PLEASE)

3-Exhaust ( can I use my stock exhaust system,I do have a 85 silencer on it)

4-Reed valves and carb mods,any suggestions? ( I need to get a #135 main jet )

BTW this a 83 model ATC 250R I plan on installing all of these goodies on...
the 1.0 over bore really doesn't bother me a lot,because I don't plan on thrashing it...

a big thanks to all of the help with this!!!!!
this site is the best hands down!!!!

[SYKO]

you need to pm. petesATC he may have your rings I jsut got everything from him for my 300 did you get a head gasket?? its a copper one the base gasket is just a regular 250r base gasket, you can use a stock exhaust but its extremely resitrictive on it, and the stock carb can be used but it keeps the performance down as well, go up to a 38 or 39 and it will be a monster only if you have a exhaust on it as well,, also when you get your rings pm me or raffa the rings HAVE to be put on in a certain way or you can cause some damage. I love my 300 its a great all around machine!

[1upfront]

Mine has a fl350 intake, 36mm pwk, boyesen pro series reeds, 82 cr450 clutch springs and a cobra pipe and silencer.:D

[Jarrod]

what kind of 38,39 carb should I look for?
as to the exhaust wich brand,etc...
thanks again.
I will try petesATC and see if he can help.

[82300R]

get with gotballs 250r, he can hook you up with any gaskets you may need.

[SYKO]

exhaust is still avail from dg, im not sure how well the dg works, I have an old hand formed jemco and it rips with it! i wouldnt trade it for anything, a 39 keihn will wake it up, im runing my 38 mikuni just becouse its fairly new.

[Huffa]

exhaust is still avail from dg, im not sure how well the dg works, I have an old hand formed jemco and it rips with it! i wouldnt trade it for anything, a 39 keihn will wake it up, im runing my 38 mikuni just becouse its fairly new.

Not that I would call for the exact same jetting since I also have a 38 Mikoon on mine but what exact jets are in yours right now. If you recall I stated mines running way rich from idle up to 3/4 throttle. That's with the air box lid on.

Does yours have any #'s on it so we can tell if we have the same type ?

[SYKO]

THE numbes on the carb are gone but I can tell you its a mikuni round slide its alittle oldschool but its a good carb, if you have a dennis kirk catoolog just look at the carb chart it will show you whats in the carb as far as jet numbers, right now im just to damn lazy to find out myself

[Jarrod]

well,Sky looks like you got petesATC last set of 1.0 rings.....
if anybody can help me in my search for another set pm me please....
the hunt continues...LOL

[SYKO]

ok man that sucks! pm raffa he's got a bud who found a bunch of 300 stuff, if you want you can also send it to this place

http://www.qande.com/

talk to vance, they resleeve the cylinder with a liquid sleeve port match it and use a modified liquid cooled big bore piston for it, the price is fairly reasonable and depending on the condition of the sleeve they can just modifie it to except the big bore liquid piston and save you even more money, like I said there price justifies the means, if petesatc didnt have the last bore setup that I got I would have sent the cylinder there to get modded.

[Jarrod]

I am pretty sure I can find some sort of rings that will work...I have everything I need to install except for the rings.I really would hate to sink more money into another big bore set up and all....
I have a good friend who is a dirt bike guru,he is helping me with this project..
it is just gonna take some time is all....
what I would really like to have is a copy of the instructions for the 300 kit...
thanks again!!!!

[ATC4ever!]

Syko,Huffa, noticed you guys running big carbs, 38,39mm and Mikuni's instead of Keihin's. Honda's came with Keihin's; is Mikuni a better carb or just easier/cheaper to work? Also is 39mm to much carb, even for a big bore 300R kit? I have a 84' 250R with a 300R kit, lucked out and found a 50 over coated piston and rings to match. Sleeve is trashed probably gonna need to be resleeved.

[Daddio]

Did you find a sleeve for it? They are also hard to come by. Parts for the 300 kit are getting harder to get every day.

[SYKO]

daddio Isnt their a compay out resleeving them now? they had kits on ebay, or I think correy sproke is going them as well.

throw the mikuni in the trash! the 300 can handle a big carb no problem! the keihin is easier to tune.

[Jarrod]

I have a spare 300 jug and head I bought off Ebay.
The sleave has a small crack at the very bottom of it.
looks likes its a standard bore also....


I still haven't worked on my 250R yet....
Haven't really looked into locating some kind of rings for it.
too much going on... LOL

[toyvette81]

where do you buy the freakin big bore cylinders? lol other than ebay i remember a while back before i got busy with other things and was really into my 250r there were some sites that had the the 300 310 330 etc...with some reasonable prices..i cannot find any of them but duncan and i cant afford them. what are they.. thanks

[Jarrod]

I bought two Hondaline big bore kits on e-bay with heads etc
I located one .10 overbore piston gaskets and all ( except for piston rings)
from a honda dealer in Iowa.

The only thing I need is a set of rings...I am sure I can get some other type
rings to work.

I have one spare jug and head. I cant remember if the dealer had anymore
pistons or not...

[Jarrod]

I meant 1.0mm overbore..ugh