MC21 Tuning
MC21 tuning: Preparing your MC21 for Track Days
There’s a few simple things to do yourself, and a selection of bolt on goodies to turn your 45hp MC21 into a 65hp track weapon. The list below is by no means all you can do, but it’ll get you enough gee-gees to give your bike a new lease of life.
There’s no particular order to the procedure.
I’ve just started from the back and worked forwards.
Wire Splice
This is necessary to remove the PGMIII restriction, and is fully documented, with pictures, in the link “Wire Splice Guide“.
The above graphs show the difference between a stock MC21, and the same MC21 five hours and a few TYGA parts later.
Oil Pump
You’ll also want to remove and block off the 2T oil injector and go to premix. This gets rid of all the unsightly and ‘in the way’ 2T oil tank and associated parts and gives a solidly reliably feed of oil to all the moving parts. Use a quality oil mixed at 30:1. There’s many good oils to choose from, but one of the best in my opinion is Castrol A747. You’ll also need to block off the oil feed holes to the carburetors.
Carbs
For ease of setting up the carburation, an HRC carb setting kit is recommended. This includes three sizes of adjustable needles (A, B & C), a selection of main and slow jets, and replacement air corrector X & Y pieces. We can supply TYGA #0 power jets at no extra cost if the jet kit is purchased through TYGA, as these are not included in the MC21 HRC jet kit.
Crankcase
If you’ve got the cases apart then there’s plenty to do here. Radius all those nasty sharp edges, and smooth off the casting flashing. This removes any restrictive lumps and bumps and keeps flow restricting turbulence to a minimum.
The next step is to fit TYGA Hi-Flo reed valves and carbon reeds. These are always good for some instant ponies. Fitted with HRC style rectifiers and lifter plates to improve power and throttle response.
Expansion Chambers
TYGA Pipes are a must! Designed with the help of TSR’s computer design program and manufactured in Stainless Steel in either SS or GP designs. Silencer available in either aluminium, carbon, carbon/Kevlar or titanium. Fast and simple to fit with guaranteed increase in horse power over the stock pipes.
Well, that’s about it. Pay careful attention to the jetting at all times. If in doubt, start rich and lean off as necessary. Make notes at every track day for weather condition, best jetting etc. and you should be rewarded with a fast but reliable track day bike.
This advice is offered as assistance only.
TYGA Performance cannot be held responsible for any machine damage, personal injury or death incurred by following the above mods.
