OzVMX Forum

Marque Remarks => Honda => Topic started by: pmc57 on February 08, 2016, 08:43:20 pm

Title: 1981 XL250S
Post by: pmc57 on February 08, 2016, 08:43:20 pm

What's an easy performance upper for a 1981 XL250S without going down the big bore or cam work path?

I'm thinking carby and exhaust as the two obvious areas, any suggestions including details would be appreciated.

Title: Re: 1981 XL250S
Post by: TT5 Matt on February 08, 2016, 09:33:17 pm

pipe it and buy a cr250 front end and some shocks with lots of adjustment knobs on them and tune the suspension to suit you and youll be going faster then if you hot cammed it with stock suspension

Title: Re: 1981 XL250S
Post by: pmc57 on February 09, 2016, 09:01:33 pm

I'm just interested in what modifications I can do with the exhaust and carby to get a bit more "fast response and action" out of the standard motor. I already have a PE front end on it and modified (longer travel) rear suspension.
Vinduro / trail riding is the only type of riding I do on this bike, I'd just like to sometimes be able to open the throttle and pop wheelies or roosts at will, have more fun in other words.

Title: Re: 1981 XL250S
Post by: Curtis on February 09, 2016, 10:26:27 pm

I used to race one, remove the balance shaft, it will spin up quicker

Title: Re: 1981 XL250S
Post by: cyclegod on February 10, 2016, 12:36:48 pm

Fit a carb with an accelerator pump, that should improve throttle response a bit. A 2valve TT250 carb may fit.

http://www.ebay.com.au/itm/XT250-carburetor-TT250-carb-XT250-TT250-/161970567267?hash=item25b632b863:g:3jYAAOSwvUlWtjKX

Title: Re: 1981 XL250S
Post by: pmc57 on February 12, 2016, 09:13:52 pm

I'm thinking of adapting either a 32mm or 34mm Mikuni VM round slide carby replacing the standard Kilen item as well as increasing the standard Twin (two-into-one) 22mm ID header pipe with 25mm ID headers and increasing the rear tail pipe section (appropriate silencer fitted) from 28mm ID to about 32mm ID for extra breathing both in and out.

Any one done similar and what's the thoughts?

Title: Re: 1981 XL250S
Post by: cloggy on April 07, 2016, 12:37:49 pm

You'll probably lose bottom end with that set up and be even less likely to do wheelies. Honda pipes of that era are often difficult to better

Title: Re: 1981 XL250S
Post by: 80-85 husky on April 07, 2016, 07:30:09 pm

get an XR from the mid 80's that's what your trying to make....

Title: Re: 1981 XL250S
Post by: skypig on April 07, 2016, 10:20:31 pm

Certainly in 1981 mine went better with an aftermarket silencer on it.
I can't remember the brand but it had a performance edge over a couple of mates bikes with the popular "Peter Allan Performance" pipes. Mine was also objectionably loud.

The decision to fit "a pipe" was made easier by the fact the stock muffler rusted out on the way home from the dealers....