archie

One thing is for sure ausy300pro, if you do buy yourself a 163cc racing version (that includes the 2007/8 175 models) and then find you don't get on with it, you'll certainly have no trouble selling it.

Not entirely sure, especially when the seller says he has upgraded the front brake. My 2007 racing spec bike has as standard a four pot front calliper, my fork yokes are also billet machined tripple clamps, totally unlike the yokes on the bike for sale.

Let us know how you get on ausy300pro . Quirky little bikes, not exactly what you want for a world round and not to everyone's taste, but a strong following amongst us lot!

A very comprohensive service carried out by the seller I see, including changing both the gearbox oil and the water !

Just a few further bits and pieces for you (although Nigel Birkett is definitely the person to ask). Please don’t take all this as gospel, but my understanding of the main differences between the standard bike and the “racing” version are (whether 125, 143 or 163), on the racing version: - Paoli fully adjustable forks - Smaller fuel tank (3 litres?) which allows full steering lock - Tubeless rear wheel Just to complicate things further my bike is registered as a TYS175 but it is a full “racing” specification bike, so don’t rely on the log book to tell you which model is which! The earlier 143cc “175’s” models were simply an over bored 125. With a 143cc piston and rings and a re-bore it’s a simple job to increase the capacity of a 125cc bike to 143cc. Both the later “175” and “200” models are both 163cc!. The even larger bore requires a larger diameter cylinder liner and the crank cases need boring to accept this. So, a 125 can also be increased to 163cc but it gets quite a bit more involved. My 2007 163cc 175 model has “200” stamped on the barrel, at the back on the bottom left hand (flywheel side) corner. Here are some of the most common mods which owners make to these bikes.: Carb: Increase the standard pilot jet from size 15 (standard) to the next size up which is 17.5. A big improvement to starting and low speed running. Exhaust: In the standard exhaust box has four baffles (steel rods) welded across the section of the inner perforated tube. The accepted mod is to remove two of these although some owners remove all four. Clutch: The action of the clutch (whether cable or hydraulic) in standard form is extremely fierce and very trials un-friendly. If you remove the vertical rod onto which the clutch actuating arm mounts, you will find a cam machined into the bottom end. The cam in turn operates against the horizontal rod which pushes against (and hence operates) the clutch. Gently softening the radius of the cam on it’s leading edge (a simple job with a die grinder) transforms the action of the clutch and in my view is the single best mod you can make. Flywheeel: Lightening the flywheel is an accepted mod which does make the engine accelerate much faster. The benefits depend upon your ability and riding style I guess. Cylinder head: The Yamaha TTR125 is obviously a mass produced engine and there are noticeable gains to be had by “sweetening” the fit of the steel inlet and exhaust seat inserts (I found nasty shoulders on both of mine ) and also by matching the inlet manifold to the inlet port (where there is a pronounced step between the two as standard). I had to play around with the carb allot after doing this, but once sorted this gave another noticeable improvement. Great little bikes. Have fun 

If you are talking about the Yamaha TTR125 derivative engine (as used in the Scorpa 125, 175 and 200 models), I think you mean engine and gearbox oil. Scorpa recomend 1 litre of Motul 300V (10W40). I have always used this oil to good effect. Do not over fill. My wife has just served me up a salad. In front of me is a bottle of olive oil and a litre of Motul 300V (used to get the spec right for this post). They don't look too disimilar. Decisions decisions

Are you entered for the Blue Bar this weekend godzilla ?

Really nice job, well done. Could you tell me what finish you used on the engine? Thanks

The service from Birkett Motorsport (01229 716806) is excellent. Never had any stocking problems, same day turn around and very helpful with advice if needed.

Since my original post I have been trying to figure out the cause of the problem, and I now seem to have it solved. Although I had the float height set accurately at 18mm, I wondered if this was anything to do with the problem. The float hinges from the back of the float chamber, and when going downhill I reasoned that the relative fuel level in the float chamber would be lower when going down hill as the float would cut it off earlier and I wondered if this was anything to do with it. I tried increasing the fuel level by setting the float at 17mm, and I am pleased to say that the problem seems to have been cured. If any other lurkers are interested in some other development work which I have done. I had the head off to check the condition and de-coke. Most of you will know about the miss match of inlet manifold and inlet port (there is a nasty step where the two faces meet), and (with the head off and using a die grinder) I gently removed quite a bit of material to match the inlet manifold to match the inlet port which is now really nice. With the valves out I also noticed that the steel valve seat inserts were also rather a

I know that Birks recomends starting at 3 turns out with a 17.5 pilot, but on my bike 3 turns is way too rich. At three turns the plug goes really sooty and it becomes less responsive. You can hear it too as the exhaust note softens. I have found my bike really likes to run on the lean side. The throttle is more responsive and it feels alot more powerful. When it was warm it would run really well on the highest clip (leanest) on the needle. Now it's so cold it runs better on the middle clip. I run a 100 main jet now having experimented with 100, 102.5, 105 and 110. I was originally thinking that the problem was carburation, but I have also lightened the flywheel, and I think now that may be the problem. It may be it's just me stalling it as the tickover is too low? I'm going to try running it with a higher tickover to see if that helps and failing that I'm going try it with the orginal flywheel back on (I bought one to lighten off ebay for

Thanks for your generous offer

Thanks for the reply. Mine does it regardless of the level in the tank, and I've checked the breather also. Any more ideas ?

When I am going downhill, the engine revs tend to drop slightly (and it is less responsive) and occasionally it coughs and dies as I open it up. I have the float height set accurately at 18mm. This is not the more common four stroke cough as I have spent a great deal of time optimsing the carb settings. It runs fine on the flat or uphill at low revs and picks up cleanly from low revs without any hesitation. The problem is ONLY when the bike is going down a drop. For your info I have the 17.5 pilot jet. Mine runs best with two turns on the fuel screw (it is sensitive to even a 1/4 turn). I have found that three turns as recomended by others is way too rich. If the bike has a tendency for the revs to drop slightly and occasinally stall when going downhill, is this a float height related issue? What is happening and should I try to increase the float height? Any thoughts would eb gratefully appreciated.