YT 175 ports vs. IT 175 ports

[bcredneck]

im manily posting this cause rubber salt wanted to see it but the yt and it jugs are intrecangable but have major diffrences in the ports this proves that theres alot of untapped power in the yt motor ive riden a it 175 and its way the h*!! faster than the yt
http://www.3wheelerworld.com/attachment.php?attachmentid=120839&d=1301445080
http://www.3wheelerworld.com/attachment.php?attachmentid=120844&d=1301445326
http://www.3wheelerworld.com/attachment.php?attachmentid=120841&d=1301445181
http://www.3wheelerworld.com/attachment.php?attachmentid=120842&d=1301445228
http://www.3wheelerworld.com/attachment.php?attachmentid=120837&d=1301444987
http://www.3wheelerworld.com/attachment.php?attachmentid=120843&d=1301445278
http://www.3wheelerworld.com/attachment.php?attachmentid=120847&d=1301446473
http://www.3wheelerworld.com/attachment.php?attachmentid=120838&d=1301445031

[RubberSalt]

Wow, that transfers on the base of that IT... I can't beleive i didn't think of that, i know how to make mine HUGE now :-D thanks a million for thos pictures. That exhaust is also pretty damn big, but i've already added my triples, a little to close to the exhaust to widen it lol. My next cylinder(if i ever get another to port) will be even better than this 1 im working on. Now the stock piston's i had, had the talls ports. The wiesco i bought had the circles. I opened them up alot. This next 1 is going to be a blaster piston. I've got pictures of them for anyone if they want to see them. They are the same height, some pin boss, bearings, same height for wrist pins.. bigger ports than the YT, smaller than the IT. But they are cheaper :).

There is still a ton of room for improvement for that IT cylinder, i wounder what the port timing is. Could you measure how from the top of the jug the exhaust and 1 of the transfers are? My program will give me the durations based on port height.

[bcredneck]

i think the reason the yt is down tuned much is the IT hits realy hard in the mid and pulls realy hard till it tops out i could see a yt fliping back real fast

[RubberSalt]

After my port job, it pulls real hard just off the bottom, damn near flips over. This is with the stock reed cage and carbon fiber petals(boyesen superstock equivilant i say), a 28mm carb... and my port job :).. with the triple exhaust!!, and a stock pipe, only 100psi, had bearing go out and damage the cylinder alot.. but what ever, it runs right? lol

to make that IT faster, squaring out that exhaust, widen the transfers, and get a blow down of 30-35 for that thing, No idea on what the port timing is. I take it, that the pulling is produced on the stock yt pipe and carb?

[200XMichigan]

Post up some good pictures of the YT175 and the exhaust you made for it?

[RubberSalt]

I've modified the xhaust ports, I'm still on the stock pipe atm. I've got some plans though, for a custom made pipe, when it's done(hopefully soon) I'll post up :)

[RubberSalt]

GOD DAMN my trailprotrailprotrailprotrailpro hauls ass for a stock pipe! lol

[Chazz of Blades]

Hey Rubber, I might just end up shipping my 125 top end for you to port some day.


Who knows, start your own company.

[Six Stroke]

I like this kind of talk! My YZ cylinder has the same style of transfers at the base. Man, I can't wait to get a hold of a 175.

[bobotech]

My YT125 is converted over to something. Im not sure what, but it has the piston that is shown on the left side of the top picture you posted. I have a 28mm carb on it too. I can't run the fuel pump though, if I do, the carb overflows. It runs fine without the carb. Has some aftermarket pipe on it (no idea what brand) and I welded a stock Yamaha spark arrestor to the tip of the expansion pipe.

Has a 11 tooth gear instead of the 10 tooth, the 10 tooth was badly chipped to the point of uselessness.

[bcredneck]

your yt 125 has the it 175 dirtbike jug if you have that pistion and a 28mm carb hats wat that pistion is from

[RubberSalt]

Now both my YT engines used the piston on the top left. The 1 with the small circles is possibly a Wiseco. The Wiseco i bought had the small ports, i opened them up nice and HUGE - well as huge as you can go without failure.

I bought a "1978" IT cylinder recently to play with, but it doesn't look like that 1. The base only has 4 bolt holes, not 4 + 2 to line it up? It also has cooling fits all the way to the base, bolts have to go in from the top. I'm getting really leery about it truly being a 78.

[RubberSalt]

I feel better, looking at ebay, things resemble it more than i thought. i know my yt head fits it.