Has any one had any experience of using bored out carbs on a TZ.
I have recently acquired a '91 3YL with 4DP barrels and CDI and on investigation found that a previous owner has bored the carbs to 39mm.
The bike pulls well, but tops out between 11-11.5k, I have checked the power jets (found one with a broken wire and repaired this) and they get 12v at high revs in neutral .
I have done a check on the settings and find as follows :-
Mains...420
Power jets..80
Pilot jets..20
Nozzels... R 3 ?? (Unlisted in the parts manual)
Needle clip.. one richer than middle.
air screws.. 1 turn out
Squish.. around 0.8mm .
Timing.. 1.59mm BTDC.
I am running at sea level using 102 octane leaded petrol and Motol 800 (motocross) at 30:1.
Has anyone any suggestions as to what difference the extra 1mm bore dia would make to jetting and why it won't rev to ( I'm told 12500-13000).
Also it won't idle, but I suppose that comes with buggering around with the carbs.
Any ideas.
Geoff.