Low-buck YT125 hop ups... A thought or two

[Six Stroke]

I've been pondering the fate of my '83. I just put a new top end on it the other day, and that in itself made quite a difference. It actually picks up speed in 4th!

Anyway, I had purchased a 175 top end off of eBay with the intent of installing it on this one. Since that time, I found a complete (sans seat and recoil) 175 for sale locally, so the plans have changed. I noticed that the 175 has a larger carb and intake flange, and also a better designed pipe than the 125.

It looks like these parts will bolt on with little or no mods, and I'm also going to throw a set of Boyesens in there, too. Maybe some 175 forks in the future.

Has anyone else done these mods? If so, were there any noticeable gains? It may be foolish for me to look for more power in a 125, but I've always been a sucker for a power boost.

[Unclediezel]

Physical dimensions are close enuff------to use the "whole" thing interchangeably

The 175 top goes on if you use the complete cylinder, head and piston ----the bottoms are identical-Exhaust doesnt interchange so use the appropriate system.

Recoils are the same(With the exception of a few "FREEKS" that are wound backwards, or have entirely different casings)
Forks are a "Bolt -on"--if you have the complete assembly---
JUST BUILD THE 175---!!!!!!---:lol: :lol:

[dirtybiker71]

Not too long ago (3 years perhaps) I bought a DG pipe for one of these (new). That plus reeds REALLY makes a difference

[smokinp]

i was talking to someone who put a Dg pipe on there 175 and they were quite impressed with it...I would think that with the mods you are doing it should work plenty good enough...

[Six Stroke]

JUST BUILD THE 175---!!!!!!---:lol: :lol:

Heh. I think you may have misunderstood me. I am going to build that 175, but I'm also gonna build the 125. A little spice! :w00t:

[Unclediezel]

Build-"A" - 175?

My point being--they are so close that ultimately you would have 2 -175's

[Six Stroke]

A wolf in sheep's clothing! Wait, more like an angry dog in sheep's clothing. It'd be really swell if I could find an aftermarket pipe, but they seem kinda hard to come by. Oh well, I'll make do with what I have, and hopefully end up with a somewhat impressive 125. I'll save my "big bore kit" for something else.

[Unclediezel]

The pipes are the hardest part of the equation--

Remember math class----the whole is the sum of its parts--Therefore if you mod a 125 with 175 parts--it will only equal at best a 175----

It does make a really nice "Sleeper " for the guys with the 110's---

[Six Stroke]

Very true, but the sum will be greater than that of a stock 125. It has been and will be used primarily on tight woods trails, so it should do alright.

[Unclediezel]

You may want to look into the gears----Im not sure if theyre different or not, but it may be worth mix-n-match--Especially if your trailing it, as opposed to straight run top speed

[Six Stroke]

I'll play around with it and see what I need. I officially dub this project "The YT that Yamaha should have built."