Author Topic: Lightweight TS250/350 - Cycle Guide article. (Read 8010 times)

mx250 · « **on:** August 01, 2009, 06:47:33 PM »

Just in case you are feeling unloved over here in Suzy World..........

TT5 Matt · « **Reply #1 on:** August 01, 2009, 08:39:35 PM »

nice read and like the power of the motor i just dont like the std ts250a frame,maybe it needs a sharpen up of the steering head angle and a motor '"drop" to get to handle

Gerard De Ruyter (Twistandshout) · « **Reply #2 on:** September 11, 2012, 08:17:46 PM »

mx250 - do you know what the 322cc donor piston was from for this big bore job?

lukeb1961 · « **Reply #3 on:** September 12, 2012, 08:46:12 AM »

Quote from: Twistandshout on September 11, 2012, 08:17:46 PM

mx250 - do you know what the 322cc donor piston was from for this big bore job?

a clue is that the TS250 is 70x64 and to get to 322 would mean 80x64
so what ran an 80mm piston back then? the TM400 had an 82mm piston.
The Yamaha RT360 had 80x70, so that could be it?

Doc · « **Reply #4 on:** September 12, 2012, 09:38:28 PM »

Someone did tell me years ago which piston was used for the 322 conversion but I can't find the pertaining email..I don't think it was RT360 due to the windows in the back of that particular model piston. Maico keeps coming to mind but I can't be sure fur sure $:-\$ The kit parts for this model are rare..over the years I was lucky to find a kit ignition and pipe but little else nor have I ever seen anything else advertised. Was told by people from the era that the trick to getting the type I and type II '69/'70 TS250 to dirt track standards was to use the same mods they used for the TR roadracer and T500 roadie as the engine is basically a T500 cut in half.

Some tech reference can be found in the links below.

http://www.ozebook.com/compendium/t500_files/grant/grant3.htm

http://www.ozebook.com/compendium/t500_files/tech.htm

TT5 Matt · « **Reply #5 on:** September 13, 2012, 01:19:09 AM »

rt1 were piston port where rt2 and 3 were reed valved type pistons

lukeb1961 · « **Reply #6 on:** September 17, 2012, 08:07:31 AM »

Quote from: TT5 Matt on September 13, 2012, 01:19:09 AM

rt1 were piston port where rt2 and 3 were reed valved type pistons

OK, so what else back in '70/'71 had 80mm or so? CZ360? Anybody know the bore of a Maico MX360?
just trying to think what piston it might have been.
What about snow-mobiles back then? Sachs or something?

Dono113 · « **Reply #7 on:** September 17, 2012, 08:24:38 AM »

Man great read.. very interesting indeed, need to find that donor piston

OverTheHill · « **Reply #8 on:** September 17, 2012, 09:14:25 AM »

talking of 80x64 i have a spare 360 Rt2 motor set up like that, [why] just because i could. Must get back to it as [do] want to know how it'll run. I used a 250 crank in a 360 cases, set piston at bottom of ports [spacer under barrel], the took ummm--6mm off top. Will run oneday, just not sure how well. I'll report in with the bad news[or good]. Always wondered what size it is so 322cc looks like it. Could have been a piston port RT1 piston [as mentioned] in the TS250 mod. Always thought a good [mod] trick on a DT360A would be an SC500 top end as same base stud pattern & 70mm stroke [way over square] just cases are cast in to edge of cylinder liner where it sits down in cases so could easily be modded. Gosh your mates would wonder what the hell you'd done to it overnight as you wheelie past. I feel another [silly] plan coming on.

Dono113 · « **Reply #9 on:** July 17, 2013, 02:21:25 PM »

Did we work out the piston type?

albrid-3 · « **Reply #10 on:** July 17, 2013, 06:22:02 PM »

I like this bike, very neat and clean lines.

albrid-3 · « **Reply #11 on:** July 17, 2013, 06:25:30 PM »

An AJS Stormer 370 may do the job.

YUMASTEPSIDE · « **Reply #12 on:** July 17, 2013, 06:48:40 PM »

I've been working on one of these myself for a while now, from what I can work out they use a Beamish piston ,as in the trials RL's, they too much wheelspin to use as solos but powered the side hacks quite well.
The Beamish RL's had the exhaust port on the opposite side to the TS's, but I am looking at making my own sleeve . The pistons are still available from France at about $280

Early Beamish 322 RL

The start of mine

Roger

Lozza · « **Reply #13 on:** July 17, 2013, 06:53:17 PM »

Geez that Ag bike come together well, though you might have to spend some $$ on the suspension, be awesome little bike

SON · « **Reply #14 on:** July 17, 2013, 07:00:34 PM »

From a bad memory the 80mm Piston was from a SUZUKI Outboard that was NLA 10 years ago.

YUMASTEPSIDE · « **Reply #15 on:** July 17, 2013, 07:07:12 PM »

.......currently available from France.....80.25mm Beamish pistons 215 Euro/$308 AUD

Its a '72 TS250,TF tank,TM250 carb, RM/PE airbox rubbers and filter/cage, alloy airbox, TM rear wheel, PE seat, DT250 head and a long way to go!!

Roger

EML · « **Reply #16 on:** July 18, 2013, 09:25:51 AM »

I was told the Beamish RL had a Massey Ferguson piston and a vent hole drilled through to the exhaust port to stop dieseling on trailing throttle.

OverTheHill · « **Reply #17 on:** July 18, 2013, 11:43:06 AM »

TS400 is 82mm, bought an RT2 yam cylinder that had one in once with bushed gudgeon holes in the piston to bring down to size, must have shortened the inlet side or drilled reed holes but would have worked regardless--too long ago but worked as it was. Thinking though that hell--80mm would be bigger than the standard liner outside [or close] so by the time it's sleeved to take an 80 piston do you need to bore the cases a bit to fit sleeve overhang down into. Must take away some of the transfer size up the side too. Cheated doing something similar [as i've written] but used 360 yam cases & cylinder with 250 crank 80x64, always wondered what i'd built but sound like 322cc. Love odd ball projects & hope it works out for you. Cheers. ps, not sure where i was heading but probably that RT1 Yam is 80mm & 'no reed holes' & may work for you. Thinking in reverse, if my TS400 piston was bushed to fit the Yam pin then you might need to say find a needle roller with bigger rollers to fit the yam piston to suzy rod--or bore the gudgeon eyes out. Anyway---

LWC82PE · « **Reply #18 on:** October 02, 2017, 11:04:51 PM »

This is from the 1974 Webco catalogue

djr · « **Reply #19 on:** October 03, 2017, 02:39:51 AM »

I don't know if this is helpful or relevant , but I have a July 1972 motorcyclist magazine with a 4 page article about a 322cc conversion to a DT1 using an RT1 80mm piston.
I don't know how to post photos on here , but happy to scan and email to someone who can if anyone is interested

David Lahey · « **Reply #20 on:** October 03, 2017, 08:13:32 PM »

The 320 Yamaha Majesty motor is a TY250 motor with a bigger sleeve, machined head, machined cases, modded transfer ports, RT3 piston and additional flywheel weight.
The "works" trials 360 motor was RT3 piston, cylinder and head matched to machined TY250 cases. TY250 crankshaft with crankpin relocated (same stroke as RT3), longer conrod and much more flywheel weight.
There was also a motor developed that used the DT400 cylinder but I don't know anything about it.

LWC82PE · « **Reply #21 on:** October 03, 2017, 08:59:55 PM »

DJR, can post it but i will put it in the Yamaha section.

Mick D · « **Reply #22 on:** October 03, 2017, 09:39:26 PM »

Love threads like this, and all the info that comes forward,,

Great looking result on this thing YUMASTEPSIDE

pokey · « **Reply #23 on:** October 03, 2017, 09:59:50 PM »

MMM Beamish. should have pic of that above every marital bed and do the lil blue pill guys out of business.

Author Topic: Lightweight TS250/350 - Cycle Guide article. (Read 8010 times)

mx250

albrid-3

albrid-3