Trials Australia Forums

Over lap the wings for strength

Looks good



Because I was doing this on.
A 11 degree day which is possibly not recommended I used a heat gun to dry the sides sone then pulled the tank out to dry the centre. Seems I did this to early as it distorted a bit. To impatient

Perfect fit front


Right side sagged when I removed the tank to early I could pack it but seems not to need it
l

Hold it down with cable ties. There is flex in the system if pushed but it springs back into position

It's not the F1 dream I had but function will do

I love the look PENETROL gives metal.


I have a carby coming. I think it's 26mm, hope so. I suspect the slide will have a longer through. So I need a era throttle longer through.
Just so happened I do have one and I had to prepare it


Dismantles, washed in petrol,marinated in paint striper, plastic ad hearing to the paint stripper, a few hours, washed in detergent, sprayed with PENETROL, assembled and I love the finish qualities.


I ported the exhaust, touched up the side ports. Typical me ported them before I every heard it run. Dose sound special, I think the bomfired exhaust helps with its clean inners. Confirming my thoughts I have had comments that it sounds like a YZ. Exhaust is tuned to 3000 more rpm till peak. I'm after a mild surge in the last 3000 rpm. At the moment it chokes for the last 3000 rpm
I may have forgotten to put the shampher on the exhaust. I don't intend to pull it apart but I'm doubting my self. If I did and it blows then I will have to take it from there


Touched up the read cage in preparation, for a larger carby. I'm thinking a 24mm is possibly best but a 26 could do the job and more. Rule number one " no Los of bottom end"
Foot pegs lowered and slightly forward. Repositioned the foot brake end.


Going for a centre mount mount, much more flow orientated.


Tried to make the 250 read block fit. Should have thought and done it before. At least prepped. Just can't get it thin enough to fit in a tight hole


A little more flow. I don't know If the boysons mare the best choice hear. Like the no stopper but if those thin ones can cope then a one piece read could do better no stops. I may be able to make one. Where on the way to removing the centre bar do I thin the centre bar out till. If I'm. Making one then I will make it to size.


May have to keep the same reed angle which will limit me in donors.

.

I'm going for a signal top and a boyson bottom. The area the top opened into is about 40% deeper than the bottom so I'm guessing they will never hit the roof and the bottom are boyesen which are designed for no stops.



Top reed is the same thickness as the two thin boyesens only thing is it is bigger so consequently harder to open
If you read Boyesens own literature they will tell you that there reeds tend to make the motor richer up top and leaner low down. In other words work better down low and not as good up top. I can see that as the larger base reed is quite thick and hard to move and the thin one on top is very soft. Withh this hybrid combo I get it all




Only theory but the top reed will be hit the hardest at peak flow. The bottom can open earlier and stay open longer. This will make les back flow and act to a small away work like a boost bottle?


Not hard to swap reeds around for finer touched

I used to say 3bikes was enough. 5 is heaven.


That bike has claimed all but one and he rode it for 75m and said that's enough


CC is its nick name and you get what you pay for. I have just about changed every thing to make it ergonomic. The suspension is just to hard. It's made for about a 90kg person and it caries 25. That will have to be next


I'm getting a lot of enjoyment out of this bike. I especially like playing with the motors when you don't know what you are doing.


If you ever asked a JC how it wanted to stand it would say like this. I'm taking it on the toy ride tomorrow. I would put money no it having the most steering lock in the paddock. That paddock could hold 5000 from all over the state I have a day rego on it. Don't have to display any thing. Hop on and we will meet, have lunch. Ride it to the DEC. have a wonderfully experience and ride home. Fun


That's a Demi Brute. I would not say the motor was angry, more having a go. The suspension, every thing is in harmony. In first gear you accelerate at about 3000 rpm and drive the front wheel up. 9 times out of ten you have to back off and reapply to keep it up there and not back flipping it i put a bigger front sprocket on it and if you catch it right you can drive it right out to 9000 rpm. It wasn't till i got a accelerator pump that i fixed the hole i created. One of my success stories.


Edit:
I had to de tune that motor

It's a 24. Disappointed. I thought it might be a 26. I'm not to concerned about the argument, small boar, draw harder bottom end. Once past the slide they open out to 26 then go through to the reeds. Why not just start with 26?


Could have been 26 so 24 will have to do still a lot of area. I will learn a lot.


The air bleed should go to the emulsion tube but it doesn't I seem be able to blow air to the air jet. Out the mixture jat but not the emulsion tube?


I want to swap float bowls so I can have the quick jet change option. Problem is the ty emulsion tube has 2 large holes and the dt has 5 small.


Needles aren't the same. I'm going to have to think about this


The tube through to. The emulsion tube is blocked. Will have to drill it out


This passage is also blacked it was claimed that this motor used to run which it could. Have as there was petrol residue in the float chamber. It would have been sucking neat fuel out the main jet and pour idling. This photo captures well how the carbs are 26mm throat shrunk to a. 24 in Thai case or a 22 for the ty.
My way of thinking is as the air enters the area after the slide it hits a big void which tumbles, eddies and messes up air flow. This is lessened as the slide opens more but as the carb is only 24mm into a 26 space it never really flows plus how much do you ever use a ty at full throttle?

The 24mm carb cleaned up ok after finding 2 more blockages the centre mount for the reed block seems to be ok


Looks bigger than the standard 22mm


I should have thought more about my bright ideas of needing more pull on the throttle when you go to a bigger carb. The ty throttle pulls plenty long enough it's just takes more twist. The example is (left) ty throttle cable is located close to the handlebars. This means you have to twist more and not as jerky. Dt trail bike centre and mx right which is either on or off. More parts for the parts bin.

I found it. It's over carbed. Muddy down low. Just needs to be tuned.

It's there


My brother once told me if inlet tube is 3 x the boar you are just moving air


Some one was thinking that in the 70 's
A26 is not going to work with this track


The shape is one cm. from the exit. It could change flow


Not happy


Needs some persuasion to see it my way


Nice

Now I know it's done I won't have to revisit it


Took to the air leaner with a pair of sizers to relax the base (photo not shown)

The top of the air cleaner had another layer of fome on it that I pealed off then trimmed the crown to mimic the lid. There is no air flowing through there (there could be).
It's a really small air box I think it will be ore right if I let the air get to it


Drill holes? Crude.


Mathematically to small
I bent the lip down but is just blocks a mother way
I'm guessing the lip is for stoping water


Not good enough


Re design
That was quite brutal with a old sharpened screwdriver


Looking better


Good spread


To small


Magic