OzVMX Forum

Clubroom => Tech Talk => Topic started by: bigtoe on June 21, 2012, 05:11:12 pm

Title: XL250
Post by: bigtoe on June 21, 2012, 05:11:12 pm
Hi, I am trying to think of ways to trim the  weight off my fat XL 250 and I was thinking would a TL 250 frame be lighter? would it be strong enough ? and would  it be pre 75 legal? has anyone got some answers ? thanks
Title: Re: XL250
Post by: sudman on June 21, 2012, 05:47:34 pm
I end up thinking same thing 1st year of production was 1975, I purchased a TL250 but ended buying 2 C & J frames from the US side port & centre port, the C & J are lighter than TL,s by 2kgs for centr port and 4kgs for the side port.
Title: Re: XL250
Post by: JohnnyO on June 21, 2012, 05:50:15 pm
I wouldn't think a TL's steering geometry and engine placement would be the ticket for motocross..
Title: Re: XL250
Post by: Eddy#36 on June 21, 2012, 05:59:26 pm
I have an  XL175 74 model rolling frame, would that be any better weight wise?, or would it fit a 250 0r 350 motor in frame?

Keen to know motor dimension differents between cc's
Title: Re: XL250
Post by: bigtoe on June 21, 2012, 06:03:27 pm
thanks for your replies, looks like I'll have to save up for one of those after market frames, I think the TL 125 came out in 74 I'm not thinking of its frame but its small light tank
Title: Re: XL250
Post by: bigtoe on June 21, 2012, 06:06:10 pm
I'm not sure about the XL175 frame maybe some else out there would know
Title: Re: XL250
Post by: Slakewell on June 21, 2012, 06:23:35 pm
I had a XL 250 with Standard frame down under 100kg with a bit of work
Title: Re: XL250
Post by: bazza on June 21, 2012, 06:33:22 pm
guys in Unzud go big bore 250 in xl175 frame
Title: Re: XL250
Post by: NSR on June 21, 2012, 06:53:50 pm
Quote
guys in Unzud go big bore 250 in xl175 frame

Really,  Do they slot straight in?     
Title: Re: XL250
Post by: sudman on June 21, 2012, 07:03:10 pm
Na they don't fit you have to do cutting and welding, but that was 350 I was looking at fitting so 250 may go in as they are shorter.
Title: Re: XL250
Post by: matcho mick on June 21, 2012, 07:46:41 pm
i'm riding a TL250 with XL350 (centreport head)motor innit,if you dont like the steering angle for MX, don't use TL front end,forks are 33's anyway,i'm thinking the 76 Xl front end might be next on my list of suck it & see's, :P
Title: Re: XL250
Post by: bazza on June 21, 2012, 08:00:43 pm
LIKE THE MAICOSPORT xl HYBRID 305CC OFTEN BETTER TAN  350 TO 460CC  WITH GODZILLA NISSAN PISTON AS YOU DONT GET AS MUCH FRAME FLEX.
Title: Re: XL250
Post by: sa63 on June 21, 2012, 08:58:08 pm
I just finished a sideport 250 (262 cc venolia 75.5 mm piston)in a 72/73 maico frame and rode it at the nats. a good thing, mine still has some bugs to work out, but handles very nicely. low ground clearance the biggest issue, which im working on now..Its around 105kg on the bathroom scale method

I will post a pic. or two

Aside  from from the c&J  & other exotica like the KSi what is a good donor frame for a centreport xl in pre 78??

For pre 78 is a husky frame a good recipient ? (light and good steel that can take modification?)
Title: Re: XL250
Post by: Swiss on June 22, 2012, 09:40:09 am
For the Swedish Honda version of the HL500 Yamaha, visit the MX web site.
http://classic50mx.com/ (http://classic50mx.com/)

Then click on 4-Takt Special in the left column and then on the Eksjo-Honda link.  You can translate the text through Google Translate for English unless you read Swedish!  Some nice bikes built many years ago that never got the publicity that the Yamaha bikes did.

Swiss
Title: Re: XL250
Post by: sudman on June 22, 2012, 11:15:57 am
Husky frames are good option and cheap to buy off ebay.
Title: Re: XL250
Post by: sa63 on June 22, 2012, 05:00:25 pm
swiss - some beauties there!!!
Title: Re: XL250
Post by: evo550 on June 24, 2012, 11:59:31 am
I was trying to do the same thing with a XT550 years ago, took it to a alloy fabricator and expliained how heavy it was and that I wanted to exchange this and that with alloy to make it lighter......to which he just looked me up and down and said "Well there's 20kg it could do without right there" cheeky barstard, I spent a fortune there getting the piss taken out of  :)
Title: Re: XL250
Post by: rmyzit on June 25, 2012, 07:33:04 am
Hi I have just finished my XL250 project and had the same idea about getting it lighter, but I keep the original frame and ground off everything that was not needed, side stand, frame lugs, brackets etc. The steel tank was replaced with a plastic item, the original seat weighs heaps so I used a plastic base seat from an early 80's KX. Numerous other steel parts have been remade in alloy. In the end though your still dealing with heavy engine so you have to get used to it. The XL250 handles grass track coarses very well and is great fun to ride and well worth the effort.
Evo
 
(http://i587.photobucket.com/albums/ss315/EVO450/Barrabool%202012/DSC00849.jpg) 
Title: Re: XL250
Post by: sudman on June 25, 2012, 09:06:12 am
Cool I like it :D
Title: Re: XL250
Post by: shelpi on June 25, 2012, 02:15:37 pm
Excellent, I want one, a job well done  :) onya EVO
Title: Re: XL250
Post by: rmyzit on June 25, 2012, 04:36:10 pm
Excellent, I want one, a job well done  :) onya EVO

No excuses for shelpi! get into mate ;D
Title: Re: XL250
Post by: Noel on June 25, 2012, 05:00:39 pm
What forks and what rear wheel have you got there RMYZIT?
Title: Re: XL250
Post by: rmyzit on June 25, 2012, 07:00:23 pm
What forks and what rear wheel have you got there RMYZIT?

Hmmmm........a scrutineers question Noel ;) XLS forks and 101.6mm rear travel
Title: Re: XL250
Post by: shelpi on June 27, 2012, 10:52:19 am
I agree EVO we dont want excuses, we want results  :D but hey ya got to admitt building a pre 68 MX out fit is nearly a good enough excuse  :o, oh yer speaking of XL250 MOTOSPORT projects can any body help me  ??? i need a set of triple clamps for the for mentioned K,K1 or even K3,k4 I have never seen one as bent and cracked as this  :-[
Title: Re: XL250
Post by: sa63 on July 03, 2012, 03:09:26 pm
 (https://lh3.googleusercontent.com/-xTT3gl5p6Xo/T_J1VeTLgVI/AAAAAAAAARo/tu0P1NTNx1U/s640/xl262%2520exhaust.jpg)

(https://lh6.googleusercontent.com/-RQhxAklf1IM/T_J1VQI6pkI/AAAAAAAAARo/1CbBCDGUNfs/s640/maico%2520xl%2520262%2520b.jpg)

(https://lh6.googleusercontent.com/-I9GrFhpQsMM/T_J1VY6SbgI/AAAAAAAAARo/RY-GL2SzOHQ/s400/XL%2520IGN.jpg)

(https://lh5.googleusercontent.com/-8GzbEDEv8so/T_J1VZRZMNI/AAAAAAAAARo/kkHDT6UxQ9g/s640/sean%2520on%2520thumpthing.JPG)

(https://lh6.googleusercontent.com/-i8pwlo4pUwE/T_J1VQtWIAI/AAAAAAAAARo/8vyrhjGuhJ0/s640/xl%2520262%2520redone%2520swing%2520arm.jpg)

Here is my recently completed/ ongoing xl 262..

maico 72/73? frame, venolia 75.5 mm piston, megacycle B40 cam, 1mm o/s inlet valves,matched porting, electronic button rotor ignition, swiss designed & inspired exhaust (1 5/8" and 4  1/4 "megaphone) , 36mm carb on methanol. Many thanks to Swiss for advice on the motor and keeping me on track when I got impatient!!
back wheel is tm 400..(wanted a mudcatcher rim to match the front.)
It was a partly done project which I got , which I got in Feb and got it  running 2 days before the nats.. motor has a good wide powerband, but is horrendously thirsty..

Its good , turns very  nicely but was too low, no paint left on the underframe.. and I think it put me on my bum once because of the frame htting the ground - the action pic shows the frame almost touching the ground.
 Also black marks under the guard tell a story. the swing arm as far as I can tell is a xl/maico combo with the lower shock point pretty low. Lots of things fell off that weekend..including the seat in one race..!!

I had Too many other things to do and the height/ shock position slipped through the cracks.
The muffler is as ugly as sin, but I had no time to anything else .. and it was LOUD through the open megaphone..

Last photo shows rearranged swingarm with lower shock mount  back  to a maico spec. and shocks extended by 20 mm. 101 mm travel now , with no springs..!

Not ridden yet since the rework...double the dirt coming up so the next outing is dirt track..yee hah!
Title: Re: XL250
Post by: rmyzit on July 05, 2012, 09:51:25 am
Wow! thats a cool XL mate, the engine sits in the frame very neatly. I'm interested in the where and how of your ignition system you have. Sorry for the hijack Bigtoe ;)
Evo
Title: Re: XL250
Post by: sa63 on July 06, 2012, 07:12:35 am
Its a HPI universal 4 stroke igniton from belguim . Ar0und $220. supplied with a blank rotor and mounting plate both machined to suit.

the cradle has been extended to fit the motor, hence poor ground clearance.

not my thread - so no hijack - bring on the xls!
Title: Re: XL250
Post by: Montynut on July 06, 2012, 08:12:25 am
What forks and what rear wheel have you got there RMYZIT?
Yours does not need to be any faster Noel we can not catch the bloody thing now ;D
Title: Re: XL250
Post by: Noel on July 06, 2012, 05:54:25 pm
Maybe, but SA63 Maico Honda is Quicker

Noel