TY 250 Improvements

Need help finding information or parts for that old machine in your shed? Someone in here will know!

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Stanm
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Postby Stanm » Sat Aug 11, 2007 9:15 pm

Yamaly, Nice looking 175. I have not seen one like thay before. What is it based on? Have you done all the mods yourself? What shocks are you using?

I have my 250 forks 8mm down in the clamps and this seems OK and I like the bit of extra ground clearance. Where is your 250 forks set Up?

I also checked the gas pressure in the falcon shocks and found one at 11psi and one at 32psi. So i pumped them up with air to 80psi as suggested. I believe the nitrogen is supposed to be around 150psi and it stops airation of the oil. It does not effect damping. Or am I incorrrect?? See the Monro web site on shocks.
http://www.monroe.com/tech_support/tec_ ... orbers.asp

Cheers



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Tee-Why
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Postby Tee-Why » Sun Aug 12, 2007 12:43 am

Stanm, try here for replica rubber bits, I dont know if he has what you are after:
http://www.4robs.com.au/

yamaly, that one smart looking 175 you have there, pity you are not bringing it over. Care to mention what mods you have done internally and externally? And where you sourced the bits from? Where will you reside in Australia?


I would rather push my twinshock than ride a modern!

Stanm
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Postby Stanm » Sat Aug 18, 2007 9:06 am

I emailed rob at 4robs and he does not have any inlet tubes for TY250's at the moment but said he will be making some soon. (Oct - Nov $40-) . I tried to soften mine with armoroil then tried WD40 with no luck. Then put it in some heated up WD40 and the shape improved but it shrunk at the hard end( carby) I then heated it up again and shoved a tube the right size into the end 40mm or so and got the right diameter again.
This has improved the shape and the fit is better but not the flexability so I am no longer concerned that it may come off. Any hints on improving the flexability of rubber bits or is it a lost cause?



Stanm
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Postby Stanm » Fri Aug 31, 2007 7:52 pm

Hi Again
We had the last round of the Vic Troy series combined with a junior development day. So while my boy was getting trained i was doing a bit of practice myself. The hills at Mt Bolton are a bit more of a challange than the slopes at Oakliegh Motorcycle track as I soon found out after a couple of spills. It didn't take that much skill to notice that i had bent one of my shocks about 20 mm off centre. So i took the shock off and positioned the high spot on my ramp and then gave it not one but a dozen or so calibrared kicks. And it freed up!!! So falcons shocks shafts are easy to fix ??? Second time lucky.

Cheers guys and thanks for you feedback on this topic



David Lahey
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Postby David Lahey » Wed Sep 05, 2007 8:29 pm

Stanm wrote:Look forward to your feedback on the reeds.

I finally fitted the Boyesen reeds last weekend. They went into the TY250D motor in my Majesty. Sad to say I have not been able to pick any difference in performance compared with the steel Yamaha reeds. I haven't done any big stuff with the Boyesen reeds yet but on logs, cambers and small quick climbs I really couldn't pick any difference.
I did discover something though with the jetting of TY250 twinshocks in the process.
I had thought the only difference between the TY250B carby setup and the TY250D carby was the main jet size (280 for TY250B and 150 for TY250D) ie I had failed to notice that the jet needles are different too.
Because I hadn't noticed the different needle, I had fitted a 280 main jet to my TY250D carby when I used a TY250B airbox on the Majesty, and had problems getting it to run right at about 1/3 throttle. I finally worked out the problem when I read the specs for both carbies again.
The reason for the difference in the jetting between the B and D models is because of the airbox design of the D model (breathes through a baffled lid entrance) being a bit more restrictive than the B model airbox (breathes through two 25mm holes in the left side of the airbox).
If anybody wants photos of what I'm banging on on about here, let me know and I'll take some and post them.



David Lahey
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Postby David Lahey » Sun Sep 09, 2007 9:08 pm

David Lahey wrote:
Stanm wrote:Look forward to your feedback on the reeds.

I finally fitted the Boyesen reeds last weekend. They went into the TY250D motor in my Majesty. Sad to say I have not been able to pick any difference in performance compared with the steel Yamaha reeds. I haven't done any big stuff with the Boyesen reeds yet but on logs, cambers and small quick climbs I really couldn't pick any difference.

Well the Boyesen reeds got a good workout today at a local trial. The bike went very well in the tight trickling bits as well as up big stuff. The only adjustment needed was to move the air screw 1/4 turn more open. I still couldn't pick any improment in performance compared with the standard steel Yamaha reeds.



Stanm
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Postby Stanm » Mon Sep 10, 2007 7:05 pm

Thanks for the feedback on the reeds. So that something i will leave off the need to do list. I dont have a collection of carbys for the Ty250 but have 4 Ty80's so know the feeling with the bits mix up.
With all the knocking about I have given the Falcons they are starting to feel a bit sloppy so will need to pull them apart and overhaul them at the end of the season. At this stage I suspect I will need a shaft or two and some seals but any hints on what else may be worn?? Also best place to get the parts.
Anyone got a diagram of the falcons?? I dont recall you mentioned the grade and quantity of the oil you used so this would be appreciated. Have you experimented with this?
By the way I pretty much settled on 15W oil for the forks

Cheers
Stan



David Lahey
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Postby David Lahey » Mon Sep 10, 2007 7:35 pm

I usually buy Falcon shockie parts from Don Newell in Brisbane.
I use 100ml per body of 10WT Shell fork oil. Yes I tried 5WT fork oil once and I thought the damping was a bit light. 75psi seems to work fine.
You don't need a diagram to work on them. They are very simple. To make it easy, find some pin-ended contracting circlip pliers that will fit inside the body about 40mm.
The top shiny bit that looks like an oil seal retainer is a dust seal retainer and is a push fit in the end of the body. Getting it out without any damage is a bit of a challenge and if you succeed, tell us how.
Below the dust seal retainer is the oil seal retainer held in by a circlip.
Below the oil seal retainer is another identical circlip.
The rod unscrews from the piston assembly.
That's it!
On my first set of Falcons, the shortlived original bottoming rubbers were replaced along with the oil seals and dust seals. The shafts were fine. I haven't touched them since and they are still great.
The other two pairs are still going strong ie nothing has worn out on them yet. I've only changed the oil in them a couple of times each.
The only other Falcon experience I have is with my buddy Cedric who replaced a shaft that was bent on the end and replaced the seals at the same time.



Stanm
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Postby Stanm » Sun Sep 16, 2007 9:28 pm

David
Thanks for the hints. I will try get some information from Falcon UK on spares and repairs and will let you know if I find out anthing useful.
Cheers

Stan



Stanm
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Postby Stanm » Wed Sep 19, 2007 11:08 pm

Hi Aagain
David wrote "The top shiny bit that looks like an oil seal retainer is a dust seal retainer and is a push fit in the end of the body"

I had the springs off the shocks to check them before the Vic Titles this weekend and noticed quite a bit of oil leakage. So I thought I would give the dismantling a go. See what you mean about the top shiny bit ( mine is made from Aluminium) I did not have much luck and thanks to your hints did not stuff it to much trying.
I was considering grinding a small groove under the flange of the top bit so I can get a grip on it with a home made two screw puller. Do you think this would work?
I will ride with the sloppy shocks this weekend.

Regards
Stan




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