Shortened Ty Inlet

[tobster]

hi

when/if you fit a barrel with a shortened inlet (eg J Shirt) to a pinky engine, the carb will therefore be mounted a cm or so nearer the engine - so, how do connect the air box rubber to the inlet side of the carb as surely it won't be long enough? that's it - I'll sit back and await the flood of suggestions

[scott_king]

Hi Tobster

I have had that mod done to my TY250 and the boot does need to be extended slightly. I have a bit of pipe connecting between the carb and the boot. I think it is made of nylon but I cant be sure. Providing it is air tight fit any pipe should work.

Also cut the top of the air box open so more air can gets in. It will improve the effectiveness of the mod.

Hope this helps

Scott

[2fargone]

Hi Tobster,

I presume you are talking about a TY mono?

If so I remember doing this mod to mine in about 90' and if I remember correctly I shortened the inlet by 12mm and still managed to use the standard carb/airbox rubber connector just by fitting a 12mm spacer between the back of the airbox where it fasten's to the frame (moving the airbox forward)and tweaking the pressed steel bracket on the top of the airbox that holds it to the two top tubes of the frame.

Hope this makes some sense to you.

[tobster]

thanks for the replies - looks like a little bit of bodging, sorry tweaking, is called for. presumably your engines were also bored out as well (270cc) or did you only do the inlet mod? If you did both, what kind of carb setting changes (eg jets) did you find works best or was it just fine tuning (eg needle position). when you've answered those questions I'll move onto the need for high octane fuel etc

later

[scott_king]

Hey Tobster

My bike was not bored to 270cc, we kept the standard 250cc but had the ports enlarged on the barrel and piston.

I am unsure about what we did to the carburettor but I think it was slightly bigger jets and maybe moving the needle a bit.

As for fuel, obviously the higher octane 98 is better but people do run them on the normal 95 with no problems.

Scott

[tobster]

Scott

as you didn't increase engine size but 'only' ported and modded the inlet length, what differences did this make to the way the engine performed? I find my standard bike runs a little rich, so perhaps all these mods may lean it out a bit and I may not have to do much replacement tuning in the carb, just adjustments (probably wishfull thinking). re your airbox mod - would this also apply to a mono airbox, as I can't think/see what I'm supposed or even able to cut off without letting in unfiltered air. Perhaps it's only for twinshock airboxes

2fargone

yers it is a mono (aren't all pinky's mono's??)

[2fargone]

2fargone

yers it is a mono (aren't all pinky's mono's??)

<{POST_SNAPBACK}>

Yes of course they are I didnt read your thread correctly sorry!

You should'nt have to cut anything of the airbox just squeeze the thin steel bracket together slightly to allow it to slide forwards 12mm.

Also,inlet mod only on my bike,if I remember correctly I did'nt do any re-jetting just a bit of fine tuning with the needle height and airscrew etc, the result was the engine revved out much higher and much cleaner,not as rich as the standard barrel.

As you say it 'leaned' it up.

(the bike I did was a white framed TY 89' not a pinky but as far as I can remember the airboxes are the same on both, could be wrong though but if I am misleading you I apologise.)

[scott_king]

2fargone

yers it is a mono (aren't all pinky's mono's??)

<{POST_SNAPBACK}>

Yes of course they are I didnt read your thread correctly sorry!

You should'nt have to cut anything of the airbox just squeeze the thin steel bracket together slightly to allow it to slide forwards 12mm.

Also,inlet mod only on my bike,if I remember correctly I did'nt do any re-jetting just a bit of fine tuning with the needle height and airscrew etc, the result was the engine revved out much higher and much cleaner,not as rich as the standard barrel.

As you say it 'leaned' it up.

(the bike I did was a white framed TY 89' not a pinky but as far as I can remember the airboxes are the same on both, could be wrong though but if I am misleading you I apologise.)

<{POST_SNAPBACK}>

Hi

I fully agree with 2fg. The mods are also on a 89TY mono.

Referring to the airbox, the standard opening on the top is not enough apparently, just extend it a bit and add a twin walled air filter. This will let the bike breath more and make the mods more effective.

When I have got time I will post sum pictures of the air filter and carburettor extender.

Cheers

Scott

[tobster]

I've had a closer look at the air box and it does indeed look a fairly straight forward job of moving it forward afew mm - it might even end up not looking like a bodge!!! Re the piccy of the airbox top mod that would indeed be v useful. I'm not expecting to have to replace jets etc as the original bike tends to run on the rich side anyway. I'm not sure if it is essential/recommended for this type of modified engine (John Shirt actually), but I think I shall probably use superunleaded fuel to try and reduce any pinking. We shall see.