Ferretflasher wrote:Have started on my next bike incorporating all the lessons learned from previous 4 machines. Latest improvement has be to adopt Fibre Reed Valve petals. As these old mono engines are based on a DT400 MX motor seems logical to fit petals for this motor. Huge improvement over the OEM steel items I obtain mine form in UK at Yambits , Borougbridge. Ask for the above type the part# is Hy Tech Reeds HT029.
Second improvement has bee to fit a 30 Flat side MIKUNI carb, choke needs moding as its wrong side and lift needle 1 notch otherwise its a superb fueling setup now, no pinking and very smooth. Throoootle cable needs shortening 20mm to use with modern twist grip.
Generally can mix it with modern machinery now no prob. More later as am with an original barrel with long inlet, aim to see if shortening has any descernable impact on the average clubman level of wobbling. More later.
Hi FF and any other readers!
I've just joined this forum so any advice both on using it and my bike problems would be appreciated!
My bike is a '92 TY250 Pinky which has lead a reasonably sheltered life spending most of its life following trials around the Hull, UK area before I brought it down to London in 2006.Then being a complete novice at trials I gradually tidied up the bike with the help of John Cane @ TY Trail & Trials mainly.
The bike is on its first rebore with the correct no.OEM piston / new small end, mains and seals (pressure tested at low PSI for 10 mins) / ultrasonically cleaned & refurbished original Tekei carb with relevant new parts (slide & bore in fair condition)/ Hy-Tech fibre reeds fitted / OEM air filter & free flow late air box / timing checked as spot on / de-coked exhaust with front box split cleaned re-packed and welded back, and a WES soft rear silencer fitted / 50:1 semi synthetic fuel mixed used (considering trying full synthetic @ 70 or 80:1...
The bike still tends to be a bit rattly (as I'm led to understand they all do) - but my two problems are knocking/pinking (only on the overrun) and the engine failing to drop its revs when I shut the throttle - giving little engine braking (indicating a lean mixture / air getting in despite all above checks?)... both these issues may be exaggerated when the engine gets hot. In desperation I have tried a colder plug by up to two steps to little effect... and whatever Keyster main / pilot jets I could get to enrichen the mixture also trying different needle heights (although naturally its the first 1/4 to 1/2 throttle opening which is problematic as higher revs are fine...)
Again, all of the above to no avail - indeed at the moment to keep things manageable, the air screw is all the way in (not 1 1/2 out) and ticker is purely on the throttle slide stop... throttle cable is adjusted with the recommended initial slack and it moves well...
What I did notice on the last stripping down is that the Hy-Tech fire reeds do not sit on the reed cage rubber facing as one might expect but are around up to 1mm off (on a bike this age the facing rubber must be quite hard, no?) - Is this significant would one think?
I am so frustrated that I am considering fitting a 28mm D slide Keihin carb - any thoughts here?
Also do Moto Tassarini do a V Force reed cage assembly which would fit this bike?
Thanks for any feedback on this!
All the best