Hello and questions!

Zitat von Baffo

On XT500's they sometimes use XT500 valvesprings on top of the normal fork springs to make this poor mans progressive springs, since the diameter of the forks are identical (o no wait you have a TT, you'll have to check that) you could go with that

I friend at home has also suggested that and I am going to try it as soon as I find some suitable springs. Another friend works in an engineering shop and assures me that he will be able to get me some.

Zitat von Baffo

Where did you get 533ml quantity from, because I think it is too much and therefor your seals will leak
Take out the springs, push the outer tube all the way up and leave 140-160mm of air in it, you can suck the oil out from the top like so:
http://westerbaen.tweakdsl.nl/XTZ750/800/imgp0294.jpg
http://westerbaen.tweakdsl.nl/XTZ750/800/imgp0296.jpg
http://www.wilbers-products.net/shop/gabelf_yamaha.htm says 160mm air for a 1TJ

I first got 533ml from "some guy" on Usenet - I asked for the specs when I first bought the bike and didn't have a manual. I now have a Clymer manual and it says 533ml as well. "some guy" probably got it from a Clymer manual

Interestingly though, the manual suggests a level of 125mm. I think I might try a bit less.

Zitat von Baffo

Linkage free play is normal if there is no grease in them (!) Grease them up, make sure all seals are in place and in good order then you will have (almost) no free play. You can even install grease nippels yourself if there aren't any, and regularly grease them up (not too much, or you will push out the seals)

Mine has grease nipples and I just happened to grease it this week. It feels much better!

Thanks,

Brian

Zitat von Don Pedro

Hi Brian,

an owners manaul you can get from :

http://www.yamaha-motor.com.au (download/ pdf)

Gruß,
Peter

Are you sure - I just checked and they don't seem to have the TT350 manual listed (any more?). Do you have a copy you can send me?

Thanks,

Brian

Zitat von trischter

You shurely know that this meant the air-chamber left in the fork without springs when the tubes are pushed completely into another.
Leaving less than these 125mm won´t change the damping overall but increases damping on the last third of compression and tendencially avoids grounding the bike after jumps.
I´d try a level around 100mm and think that will do with your weight.

No I did not know that. I have a fair bit of experience with motorbikes, but it is all self-taught and mainly engine. I know next to nothing about suspension tuning.

I was actually think of going the other way - "less" above meaning less oil = more air. Although my plan was to first check if 533ml of oil = 125mm of air, just to sanity check the manual specifications. What you are saying about more oil = better "end of stroke" damping makes sense as well.

It sounds like I should do some more reading. I have tried to search for suspension tuning articles on the net but have only been able to find people wanting to sell their services. Any pointers? I might even consider buying a book if there is consensus (I won't hold my breath for that here...) on a good one.

Thanks,

Brian

Sorry, I was not clear. I already have the Clymer manual. I was asking for pointers to suspension tuning articles or books.

I took my bike out again today. About 35 degrees C and lots of dust - urgh.

Anyway, I spent a bit of time playing with the suspension. I used up the last few mm of rear spring preload and turned the damping up quite a bit. I can't say how much as the clicker does not click - I think it is about 7 clicks from hardest, which is softer than standard according to Clymer! I think it was set very soft when I bought it. It now feels OK. I does not bottom out on jumps (although I might not have been riding as hard today), holds OK through whoops and is not too jarring. I ran out of time, but I think I might try a little softer on the damping next time. The rear is close.

The front is a differnt matter. Still leaking badly! This week I am going to pull the front forks apart again. Install new oil seals and dust seals and 12.5wt oil (I have a litre of 15wt and I'll buy a litre of 10wt and mix them). I am also going to try 10mm more oil/less air.

From the bit of reading I have done (Google search for suspension tuning articles) I think the springs are close to the right strength for me, from checking the sag. But, they are a little harsh (15 wt oil too heavy as suggested here) and do bottom out (too much air space).

I don't get to ride often, but I will report back after my next test - should be the weekend of the 11th of March.

Thanks,

Brian

Zitat von Baffo

http://www.yamahaownershandbook.com.au/?r=0

Thanks - just what I was after. The link is there on the Yamaha Australia home page under "Support -> View Owners Handbook". I just could not see it...

I was also able to get a manual for my son's YZ80H from here, which is a very good manual. I now know where to look for the timing marks on the magneto and set it correctly rather than by guess

Zitat von Baffo

Suspension tuning:
http://www.ohlins.com/pdf/ultimate_tuning_bike.pdf
http://www.ohlins.com/pdf/mx-enduro-…k_absorbers.pdf
http://www.ohlins.com/pdf/mx-enduro_front_fork.pdf

Although this was mainly Ohlins specific, there was some general theory. I already know and understand the theory presented there. I think maybe it is not that difficult and I just need to go and implement the theory rather than just thinking about it!

Thanks,

Brian

Zitat von Don Pedro

In Australia , the TT 350 was sold till 2000. Since 1996 the frame was coloured in blue.
Can you find out, how the modeltype is called ? (picture)

I was in my local Yamaha shop today and asked. He had a look around and said that the newest fiche he had was for 1993 and the model code was 4DR - same as your 1992 model. The Yamaha manual download site only has them up to 1993 as well so no hints there.

Brian

Well, that was not too hard - I now have my forks set just right. I drained the 15wt oil, pulled them apart, cleaned everything and put back together. I then put in 500ml of 10wt oil and 100ml of 15wt. I pumped up and down a few times to ensure it was well mixed and then used a syringe to suck out the excess (about 35ml) oil to take the level to 110mm. I spent most of the weekend on the bike and the seals did not leak and the feel it great!

Now I need to work on the rear shock. I have the spring preload as tight as it will go and I experimented with the damping through the weekend. I think my shock might be broken as the damping adjuster does not click very well when it is turned and it seems that at one position it is very soft and bottoms on small jumps and on the next position it is way too hard. The manual says there are about 35 positions so I would not expect to find such a difference with just one click! Has anyone had experience similar to this with the rear shock on a 1990 TT?

Brian