Mito 443 Project
Discussion
Have got it running quite nicely on the PWKs now, unfortunately we didn't have the right needles at Dave's and only pilots up to 58s, which you'd have thought would be big enough but she's bloody thirsty! Maybe it's a feature of the PWK air strikers, it's certainly gulping plenty of air in. Unfortunately it was one of those catch 22 scenarios where the 58s realistically were still too small but going that large was dogging the engine in other areas as we needed a leaner needle. So we ended up with smaller pilots and barely cracked open air screws, Dave as usual didn't want to give up which was great but I think we were never going to get anywhere with the bits we had on the day. What was very promising though was it did something like 160 runs on the dyno and they were all ultra consistent and we could track every change we made.
The most it did on the day was I think around 102 at one point, but most runs were nearer the 98-100 mark, which is still a lot of power at the wheel, but when I took the bike out a few days later I could notice the power loss - BUT, also noticed that there was much more potential in these carbs and it was very smooth.
Ive been playing with it after work just changing little things and heading out. I've now ended up with a much leaner needle, slightly fatter mains and considerably bigger pilots allowing me to actually get some use from the air screws which has made all the difference, it just picks up and goes now when cracking the throttle open, pulls through the flat spot much better before it comes on the pipe and feels bloody fast, so there's no doubt in my mind it's got to be back to somewhere nearer the 105-110hp region, it certainly feels way better than its ever been and I'm not even finished yet.
I've got a few more tweaks to make then when I'm happy with it I'm going to do a top end refresh, run that in and probably take it back to Dave's for any fine tuning/verify it's safe. Also waiting for a new ignitech quickshifter sensor as mines given up, the way it makes its power it's much nicer to ride with that working!
The most it did on the day was I think around 102 at one point, but most runs were nearer the 98-100 mark, which is still a lot of power at the wheel, but when I took the bike out a few days later I could notice the power loss - BUT, also noticed that there was much more potential in these carbs and it was very smooth.
Ive been playing with it after work just changing little things and heading out. I've now ended up with a much leaner needle, slightly fatter mains and considerably bigger pilots allowing me to actually get some use from the air screws which has made all the difference, it just picks up and goes now when cracking the throttle open, pulls through the flat spot much better before it comes on the pipe and feels bloody fast, so there's no doubt in my mind it's got to be back to somewhere nearer the 105-110hp region, it certainly feels way better than its ever been and I'm not even finished yet.
I've got a few more tweaks to make then when I'm happy with it I'm going to do a top end refresh, run that in and probably take it back to Dave's for any fine tuning/verify it's safe. Also waiting for a new ignitech quickshifter sensor as mines given up, the way it makes its power it's much nicer to ride with that working!
Yazza54 said:
Anyone got either lying around unloved they want rid of? Even a rolling chassis would do.
The 1st post in 2013 
You my man have some serious patients for that project 
. The trouble is with these projects is they become so involved that when you finally achieve the perfect bike you will get bored and sell it, Don't forget to drop me an email when that happens please 
Bloody photo f
ket ruining yet another long term thread. It doesn't feel like it's been that long! It's about 2 years since it first ran, probably been on the road a year and a half or so. There's been periods where I've not done much with it too, it spent a long time at my parents house when I had garage problems etc. I can't see me getting bored of it. It was very frustrating pissing in the wind constantly with the old carbs but a great feeling to be finally getting somewhere.
Gutted that Photobucket has ruined the thread
Gutted that Photobucket has ruined the thread
Great service from Martin (mad biker designs) as usual. New 68mm wiseco pro lites, rings, little ends and pins. New base and reed gaskets too and going to try some Evans waterless coolant in it. Might do this at the weekend but more interested in fine tuning the jetting at the moment. Have gone what feels like too far now on 170 mains so going to spend some time gradually coming back down. I've bought the in between sizes, I.e. 162,168 - think it'll end up on 165s which it felt pretty good on. It felt lean on 160s and too rich on 170s but I'll try the in between ones anyway.
Edited by Yazza54 on Thursday 10th August 18:59
As far as I'm aware probably just helps reduce weight given that this is the meatiest part of the piston. Might help keeping it cool too. Seen loads of 2 stroke pistons with holes above the pin, some with quite large reliefs down the side of the piston too but other than reducing friction I'm not sure what the purpose is.
Yazza54 said:
As far as I'm aware probably just helps reduce weight given that this is the meatiest part of the piston. Might help keeping it cool too. Seen loads of 2 stroke pistons with holes above the pin, some with quite large reliefs down the side of the piston too but other than reducing friction I'm not sure what the purpose is.
Expansion points. Allows the piston to expand rather than bulge out. The area under the rings around the ex port gets hot and these allow the material to deflect into the hole rather than bulge and increase friction. Which increases heat. Which increases friction.Which increases heat.Which increases friction. Which increases heat.Which increases friction. Which increases heat.Which increases friction. Which increases heat. Which isn't a good thing on a 2T. 
Edited by Steve Bass on Saturday 12th August 08:38
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