Re: QT50 and SHA slide tuning

Found my drawings, all holes are 4.5mm off the centre line, first pair 4mm up, second pair are 8mm up. I centre drill to pilot and produce a little funnel, start at 0.8mm and try that, you can then open them up as required but open them up too far and you'll get runaway idle. There is also a cut out I machined at 30° just cutting into the front face of the slide but you could file that out with a ½ round file, easier to do on a mill and keep it centralised.

Here's a pic of a slide closed, this is an early iteration when I was trying flat bottom cut outs and different hole positions, but it gives you an idea.

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Apologies for the pants picture quality, took this on my endoscope.

See how you get on and try the 3d printed slide (that's what inspired me) but your welcome to dm me if you really get stuck and I'll cast another batch. I think Jay's right tho, I think the air filter may also be causing you problems, I'm still running with all mesh screens.

Re: QT50 and SHA slide tuning

The problem with the 3d printed slide is the boosts are centered so they just hit the emulsion tube and gives you that runaway idle. Kinda like cruise control, but kinda scary when you let off the throttle at 30 and it starts gaining speed on its own. Ha!

Re: QT50 and SHA slide tuning

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Really appreciate this tom! Thank you. Ill keep you all updated gonna be busy the next few days with work and got some bad weather ahead so things are hold for now.

Re: QT50 and SHA slide tuning

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Referencing your other post Jay, im assuming you could not get past the run away idle problem no matter how many screens you removed from the pack, is that correct? With the information you provided me yesterday about air flow and the screen packs im thinking that i can possibly get the #6 i filed down to work with some airfilter tinkering or even the #7 or #9 that were making the clutch grab before i could the engine to not stall out

Re: QT50 and SHA slide tuning

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So i got my order from treats today. They sent me a #8 slide by mistake which is quite interesting because they don't have the #8 listed on their site. Wondering if I should keep it since they don't make them anymore

Re: QT50 and SHA slide tuning

what’s it look like!

post pics!

Re: QT50 and SHA slide tuning

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Actually that's probably a #9 isn't it

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Re: QT50 and SHA slide tuning

yup, that’s a #9

close call tho!

Re: QT50 and SHA slide tuning

Yeah the runaway idle on the 3d slide was not fixable without blocking off the added boosts. In a piston port bike it is not as bad but the reeds really kept it going.

Re: QT50 and SHA slide tuning

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update for you guys:

It took off the screen pack and mesh filter and decided to try uni foam air filter which seems to be playing really nicely with the 3D printed slide. I'm using a 72 size jet in there which may be a size too big but my head temperature was getting up to a 370s with a 70 jet. No runaway idle issues from what I can tell so far but I didn't ride too long because this fucking wind is just unbearable where I live. With the wind it's hard to say what my top speed could be, GPS clocked me out at 33 but I was doing mostly 32.

Saw a guy on Reddit with pretty much the same setup as me except he had a biturbo Tomos ehaust, was using the stock slide in the SHA on his QT and was running an 82 main jet. He's thinking he has an airleak in the crankshaft seal which would account for the larger jet. He said he was doing 40 with that setup although I suspect it won't last with that faulty crank seal. Nonetheless an impressive speed to reach as I'm about 8mph behind him

Re: QT50 and SHA slide tuning

I run at about 40mph on my stock tomos with a 15 Sha and estoril pipe. Just keep tuning. Just make sure to be methodical about it. Changing up too many variables at once is not going to help the process.

I do plan to throw in the other slide from Tom into the tomos and see how that does.

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