Trials Australia Forums

Hi Everyone,

So I am really happy with all of the little modifications on my TL 250 and I never would have guessed that to make it better, you first must make it heavier!
The grips no longer slip.
The clutch and brake cables have a much nicer action.
The throttle is smoother and less vulnerable to interference.
A more substantial fork brace now holds the mudguard.
The 600 gram heavier flywheel really makes it much more rideable especially in tight turns and boulderfields.
Practice has made me better at predicting when it wants to lay down and have a rest!
Likewise with counteracting such desires, sometimes simply by slide of hand......

One of the other things that made it better was slightly more preload in the forks and new seals. When they made these, they were not cutting corners on quality or materials used:


Here is something that I have not seen before in bikes from the mid 1970s, the sliders have guides as standard, this might be an option for worn sliders on other bikes.

Here are some action shots:

It's very nice to see what things you have done to make that easier to ride in sections. I love seeing what setup and tuning changes people make to their twinshocks.
Have you found that this bike is easier to ride in some situations than your other twinshocks in those situations?

Hi Everyone,

David Lahey wrote:It's very nice to see what things you have done to make that easier to ride in sections. I love seeing what setup and tuning changes people make to their twinshocks.
Have you found that this bike is easier to ride in some situations than your other twinshocks in those situations?

David, that is a very interesting question and I have pondered over it for some time as it is difficult to answer. The main reason is my twinshocks are quite diverse and start at 1970 through to 1985, this covers some fairly major changes and development.
IF for example I could add 1970s to your question?

David Lahey wrote:Have you found that this bike is easier to ride in some situations than your other 1970s twinshocks in those situations?

Then it is considerably easier.
The TL 250 has power to burn up hills and it bites in and tracks up hill rather nicely!

Wondering about this made me curious enough to do a swingarm comparison on a pegboard that coincidentally is like 25 mm grid paper:

There are 12 swingarms in total, a Dirty Dozen if you like:

Right to Left is shortest to longest:

Perhaps this photo depicts the lengths a little better:

Interesting how cover both of the extremities!
What does all this mean you ask?
Well you have probably worked out that were on to a long swingarm before all of the others!
In fact TL 250 is the same length as TLR 200 and TLR 250.

Now back to your question as you asked it. Firstly a little on my TL 250, it came to me about 15 to 18 years ago with those Marzzochi shocks and I can remember playing with the preload and rebound a long time ago. They are maybe 20 mm longer than standard and work quite well.

Now I am thinking that the combination of long swingarm and long travel on the back along with a torquey motor is a good set up! The TL 250 of mine has an uncanny ability to recover from a bump and track straight up a hill and do it with ease even on a bump like this:

David Lahey wrote:

Greg Harding wrote:Hi Everyone,

On another note, I was asked recently about weight distribution on my SQUEAMISH and I didn't have an answer. From memory the motor went forward 15 mm in the frame and that was achieved at the front at least by fabricating new engine mounts.
So to summarise, the crankshaft centreline location makes sense for working out the weight distribution for a static bike. However the nut holding the handlebars seems to move around quite a bit in every direction so that might be a very different equation?

So I guess that means that the Squeamish engine relocation was intended to go along with the use of a longer swingarm without lengthening the wheelbase?

I guess I've been conspicuous by my absence but I've just seen these posts so here goes.

I still have the "Squirmish" and it get ridden regularly. Apart from a random problem that feels like loading up it's still a lot of fun to ride.
When time allows, I'll weigh and measure mine as it would be good to compare to the real Squeamish.

I lowered my footpegs and moved them forward for a great improvement in climbing and turning.

As an aside, I've spent the last few months converting my KTM Freeride from petrol power to battery electric and getting it registered.

Hi Everyone,

brent j wrote:I still have the "Squirmish" and it get ridden regularly. Apart from a random problem that feels like loading up it's still a lot of fun to ride.

Excellent to hear Brent, you have me curious about what carby you are running? The standard 28 mm is a little big in my opinion so I fitted a 26 mm round slide OKO and it runs a lot better right off the bottom and is better right through the rev range.


The mounting (insulation) block is a Mikuni part straight out of their catalogue and bolts up. The main problem was getting the original air cleaner boot on to the carby. That was a little like Blacksmithing, heat beat repeat. To start with I soaked it in boiling water to heat uniformly and soften and then forced it on to a warm aloooominium tube. Then I split a bigger aloooominium tube, inserted and used tyre levers to stretch the boot. This needs to be gradual to avoid splitting and I was using a heat gun as it was more convenient than hot water. The aloooominium helps prevent overheating the boot so heat a little, stretch a little, rotate a little, heat stretch repeat.......


Knowing you are a fitter machinist so I will use Engineering terms: You need to stretch the Firetruck out of it!

Greg Harding wrote:Hi Everyone,

brent j wrote:I still have the "Squirmish" and it get ridden regularly. Apart from a random problem that feels like loading up it's still a lot of fun to ride.

Excellent to hear Brent, you have me curious about what carby you are running? The standard 28 mm is a little big in my opinion so I fitted a 26 mm round slide OKO and it runs a lot better right off the bottom and is better right through the rev range.

IMG_20250221_143505.jpg

IMG_20250221_143452.jpg

The mounting (insulation) block is a Mikuni part straight out of their catalogue and bolts up. The main problem was getting the original air cleaner boot on to the carby. That was a little like Blacksmithing, heat beat repeat. To start with I soaked it in boiling water to heat uniformly and soften and then forced it on to a warm aloooominium tube. Then I split a bigger aloooominium tube, inserted and used tyre levers to stretch the boot. This needs to be gradual to avoid splitting and I was using a heat gun as it was more convenient than hot water. The aloooominium helps prevent overheating the boot so heat a little, stretch a little, rotate a little, heat stretch repeat.......

IMG_20250221_150350.jpg

IMG_20250221_150341.jpg

Knowing you are a fitter machinist so I will use Engineering terms: You need to stretch the Firetruck out of it!

Love the "engineering terms"!!

My carb is a flatslide OKO from Mid Atlantic trials that was supplied as pre jetted kit. It included a manifold similar to yours and a rubber adaptor to join the std air intake hose. Due to the different position of the motor I had to shorten the intake hose and glue the adaptor in place.
I'm having a problem where, once it is hot and it stalls or I turn it off it will start after 15-20 kicks and it runs like it's loaded up. Hold the throttle full open and it just blubbers until it clears and revs. Once it cools it starts on two kicks as it normally does. I've swapped CDI units, replaced the plug cap with a new Suzuki one (5k resistance) replaced the coil with a new Suzuki one, several new plugs and swapped out the stator for a TS250A unit. None of these things made any difference. Yesterday I pulled the plug as soon as it stopped, and the plug looked oily so i put in a new plug and it started straight away. I've drained the tank and will refill it next weekend. The bike was jetted in June-July at around 20C and 20% humidity. Currently it's 35C and 90+ humidity. I also run an oil feed to the LHS main bearing so I'm inclined to think it's loading up on oil. I was running about 30:1 fuel mix. I think the oil pump may supply enough to lube thee motor but I'll run maybe 60:1 just to be safe.
I'll measure the bike and post up the specs to see how close it is to yours. I recently moved the pegs forward and down for a massive improvement in climbing and turning.
The purists will hate me for this but the RL really was a pig of a thing to ride and a few changes make them a different bike altogether.
I've been putting a lot of time on my BEV converted Freeride. The available torque without revs or speed makes it hard to judge how the RL is running.

brent j wrote:

Greg Harding wrote:Hi Everyone,

brent j wrote:I still have the "Squirmish" and it get ridden regularly. Apart from a random problem that feels like loading up it's still a lot of fun to ride.

Excellent to hear Brent, you have me curious about what carby you are running? The standard 28 mm is a little big in my opinion so I fitted a 26 mm round slide OKO and it runs a lot better right off the bottom and is better right through the rev range.

IMG_20250221_143505.jpg

IMG_20250221_143452.jpg

The mounting (insulation) block is a Mikuni part straight out of their catalogue and bolts up. The main problem was getting the original air cleaner boot on to the carby. That was a little like Blacksmithing, heat beat repeat. To start with I soaked it in boiling water to heat uniformly and soften and then forced it on to a warm aloooominium tube. Then I split a bigger aloooominium tube, inserted and used tyre levers to stretch the boot. This needs to be gradual to avoid splitting and I was using a heat gun as it was more convenient than hot water. The aloooominium helps prevent overheating the boot so heat a little, stretch a little, rotate a little, heat stretch repeat.......

IMG_20250221_150350.jpg

IMG_20250221_150341.jpg

Knowing you are a fitter machinist so I will use Engineering terms: You need to stretch the Firetruck out of it!

Love the "engineering terms"!!

My carb is a flatslide OKO from Mid Atlantic trials that was supplied as pre jetted kit. It included a manifold similar to yours and a rubber adaptor to join the std air intake hose. Due to the different position of the motor I had to shorten the intake hose and glue the adaptor in place.
I'm having a problem where, once it is hot and it stalls or I turn it off it will start after 15-20 kicks and it runs like it's loaded up. Hold the throttle full open and it just blubbers until it clears and revs. Once it cools it starts on two kicks as it normally does. I've swapped CDI units, replaced the plug cap with a new Suzuki one (5k resistance) replaced the coil with a new Suzuki one, several new plugs and swapped out the stator for a TS250A unit. None of these things made any difference. Yesterday I pulled the plug as soon as it stopped, and the plug looked oily so i put in a new plug and it started straight away. I've drained the tank and will refill it next weekend. The bike was jetted in June-July at around 20C and 20% humidity. Currently it's 35C and 90+ humidity. I also run an oil feed to the LHS main bearing so I'm inclined to think it's loading up on oil. I was running about 30:1 fuel mix. I think the oil pump may supply enough to lube thee motor but I'll run maybe 60:1 just to be safe.
I'll measure the bike and post up the specs to see how close it is to yours. I recently moved the pegs forward and down for a massive improvement in climbing and turning.
The purists will hate me for this but the RL really was a pig of a thing to ride and a few changes make them a different bike altogether.
I've been putting a lot of time on my BEV converted Freeride. The available torque without revs or speed makes it hard to judge how the RL is running.

RL250 “Squimsish”
Measurements taken with the bike on a stand with wheels just touching the ground with suspension on full extension.
Wheelbase 1360 (1335-1370)
Rear axle to footpeg 405
Ground clearance 365
Swingarm pivot to ground 475
Footpeg to ground 410
Swingarm length 430
Front axle to triple clamp 805
Fork angle 28
Frame rake 26
Front weight 44kg
Rear weight 54kg
Full fuel tank on bathroom scales

photo to come

Hi Everyone,

brent j wrote:"Squirmish"
Love the "engineering terms"!!

My carb is a flatslide OKO from Mid Atlantic trials that was supplied as pre jetted kit. It included a manifold similar to yours and a rubber adaptor to join the std air intake hose. Due to the different position of the motor I had to shorten the intake hose and glue the adaptor in place. Is that 26 mm or 28 mm? Also can you please post a photo of the intake assembly (adaptor)?
I'm having a problem where, once it is hot and it stalls or I turn it off it will start after 15-20 kicks and it runs like it's loaded up. Hold the throttle full open and it just blubbers until it clears and revs. Once it cools it starts on two kicks as it normally does. I've swapped CDI units, replaced the plug cap with a new Suzuki one (5k resistance) replaced the coil with a new Suzuki one, several new plugs and swapped out the stator for a TS250A unit. None of these things made any difference. Yesterday I pulled the plug as soon as it stopped, and the plug looked oily so i put in a new plug and it started straight away. I've drained the tank and will refill it next weekend. The bike was jetted in June-July at around 20C and 20% humidity. Currently it's 35C and 90+ humidity. I also run an oil feed to the LHS main bearing so I'm inclined to think it's loading up on oil. I was running about 30:1 fuel mix. I think the oil pump may supply enough to lube thee motor but I'll run maybe 60:1 just to be safe.

30:1 sounds a bit much to me when you consider that you are injecting oil as well, 50:1 on my old 2 strokes.
The SQUEAMISH was suffering similar symptoms and I chose the other rabbit hole that smelt like fuel. Mainly because I was able to replicate the problem at will, it happened more often with a full tank and even more often descending down steep hills. My thoughts are the one way valve in the fuel cap was sealing too well while manhandling the bike over obstacles and the pressure had to go somewhere with the next weakest point being the needle and seat.

IMG_20250302_111421.jpg (939.2 KiB) Viewed 4144 times

IMG_20250302_113604.jpg (508.68 KiB) Viewed 4144 times

IMG_20250302_113541.jpg (710.61 KiB) Viewed 4144 times

The valve can go in 2 ways and I think it is meant to let air in as fuel level goes down? The parts book is no help:

IMG_20250302_114656.jpg (538.61 KiB) Viewed 4144 times

The workshop manual has me thinking there is a conspiracy:

IMG_20250302_115553.jpg (843.52 KiB) Viewed 4144 times

To be fair, I think were not considering what can happen in Trials riding and the workshop manual reads very similar in other examples for different models. What do you think?

I had a TL250 for a few years and loved it.
One problem that took a while to find was continuous stalling at low revs. Turns out it was the cam wearing in the head and varying the timing due to the continuous changes in the points gap.
I found it to be a great hard trailbike, a bit like my KTM Freeride turned out to be.

Regarding the Squirmish.
Here are the "specs".

RL250 “Squimsish”
Measurements taken with the bike on a stand with wheels just touching the ground with suspension on full extension.
Wheelbase 1360 (1335-1370)
Rear axle to footpeg 405
Ground clearance 365
Swingarm pivot to ground 475
Footpeg to ground 410
Swingarm length 430
Front axle to triple clamp 805
Fork angle 28
Frame rake 26
Front weight 44kg
Rear weight 54kg
Weight measured with a full fuel tank on bathroom scales

Hi Everyone,

Brent, your photos bring back memories of living in Darwin, the coolest place is usually under the house. The dimensions are very similar to my SQUEAMISH, it would be good to see them side by side.

TL 250s do get some bad press, I think the tripple digit weight is rather hard to ignore and I still laugh at claim of 99 kg. You wish jelly fish! The heavier Motosport flywheel makes it harder to stall and smoother off the bottom. Were you having cam wear problems at higher ambient temperatures? There has always been a theory that TLs suffered more from this because the XL was generally ridden faster...

In other news a Mate of mine ended up with these 2 TY 250s:


He wanted to keep the matching numbers "A" model and make it more complete. So I supplied him with most of the missing parts and in exchange I ended up with the "B" model:


It is not matching numbers and quite a few parts are wrong, can anyone identify the non genuine TY 250 B model parts?