set up is mhr team 70's mhr main bearings mhr team pipe polini evo 2 crank polini straight manifold polini evo reed block malossi delta clutch polini kevlar belt polini super speed variator with 6 3.7 gm and 3 5 gm rollers deloroto pghb21mm carb with 115 main jet and needle clip in 4th ritchest position it runs perfect with no problems very fast lifts up on power premix at 40to1 but still seems to be running lean because done a plug chop an it is still grey surley it shouldent need to be more than 115 mj? also checked there is no air leeks
MHR Team without a long stroke crank? Sounds interesting... You should really be running a 25mm carb or larger on specs as high as that.
didnt know u had to use a longer crank in the mallosi booklet that comes with the 70's it ses with the mhr team kit minimum of 19 mm carb i have got 3 spare 24,26 and 28 carbs which one would u think would be best then?
i will use the 28mm just gotta get a bigger inlet manifold how much quicker will it b with the 28 than the 21?
I'd try both the 24 and the 28. One could end up performing better than the other as it's not all about size. But 21mm really is too small. The MHR Team is built for a 85mm conrod. It's not the worst thing in the world to run a 80mm conrod but it will be slightly down on performance. I worded my first post wrong as i meant a longer conrod not stroke. It has the same stroke as stock just with a longer conrod. Of course you also should be running 98 octane fuel.
ok thanks i will order the manifold then seems 2 run very well at the moment very quick lol and i do run 98 octane and fully synthetic oil when i get the manifold i will see which runs best after setting each carb up n post results
Right so after seeing the picture of your bike i now realise your specs are not quite true. It's a MHR air cooled kit. Not an MHR TEAM. Two completely different kits. Ones air cooled and a hell of a lot slower and one is LC and a complete beast. You will only ever be getting about 14-15bhp out of the kit though as one of the best scooter tuners is the world only managed 18.5bhp out of a ported and setup on the dyno MHR air cooled. Your exhaust is too high revving for your kit as well. Malossi themselves don't even advise it and they are known for going for the most over the top and expensive addons. Hell you may even should be running 95 octane. I would personally only run around a 25mm carb on an air cooled MHR kit but still try it and see. A good side though is that the air cooled kit is built for the stock stroke and conrod size.
incase your all wondering WHY the conrod length maters if the stroke is the same.. the angle of the conrod at firing point is alot diff with a longer conrod so more of the force is applyd laterally to the crank (basicly the longer the rod the straighter it pushes on the down stroke) this basicly means if you run a shorter conrod where a longer one is recomended the power the kit produces is basicly wasted pushing the crank round where it already has power to move and wasting power past 90 degrees past tdc
