125 A/B barrell and head can be YZ or MX not fussed

[Freakshow]

Thoughts its about time i brought some of these projects out  from the dark spaces in the shed to see some light, one i want to get going on the back burner is one of the YZ125a's,  but some things need loving on the one i pulled out, so for starters im on the hunt for :

125 A/B barrell and head can be YZ or MX not fussed.

also what is the rod kit for that model or who is doing them for a good price, and or variation model that also fit, zedder says 250/360 same which i dont belive but rod in it says 1G8, and that dont sound right either 

Seat cover for same.

Forks that fit and are pre 75 ( even ideas as i may have some here)

it looks like most 175/125 Dt or MX stuff is the same any one confirm that. 

is the hatachi black box the same as the MX250/360 or is it somthing else again ?

Where can i get or what rear sprockets fit ( they look a bit weird with a dish or can i shim it our and use a normal Ali rear sprocket)

[vandy010]

i can't help with any parts freaky but even an early DT125 barrel will work, {with a port job of course} but dont use the earlier AT2,3 barrel.
rods, anything from the early DT,YZ,AT,CT,MX 125/175 will fit. {1G8 is YZ125x and is fine}
seat cover, mine is from VMXR in the states, check ebay.
forks, 34mm DT forks if you must and they'll still be pre~75legal. the 34mm units will work better than the std 30mm units.
CDI box=? i dunno.
rear sprokets, yamaha still does steel items for the AG bikes avaiable in 47t or 51t in 428 pitch but you'll need to drill a few extra holes in them=easy.
we'll need to see progress pics of course

[Freakshow]

Kay thanks, also heard the 3RZ rod kit fits (yz100G/H) , but i dont want to order this stuff unless it works, im not good at coping when i spend $200 and its out by 1mm or too long by 3mm.

So are we sure a 1G8 or 3RZ rod kits are just plug and play ?  Stick with genunie or should i venture onto the wisco or hot rod site s?

I think this bike has a At or aggy somting pissy barrel on it, just know it dont look right, same with the exhaust seems to be cut at the front to fit an agle to make the ex port.  - so i need to sort one out.

Do the 34mm forks slip in or do you have to open them up and remove steal ? im not sure i want to cut the holes bigger ? i got a set of Dt forks here and some YZ250A ones so ill have a play with that concept.

can you get ali rear sprockets and shim out the dish ? the steal one ways more than me.

[Freakshow]

Also swing arm ? the one in it has been braced, can be shaped to look better as its just flat bar weled on, but a nice mx or yz or what ever else fits in would be nice to know too.....

[Lozza]

Longer rods 'work' better Freaky.

[Freakshow]

not when they hit the squish

[DJRacing]

Freaky the rod is 3R2

[Freakshow]

ooops soz typo, yep ment 3r2, thanks DJR

HAs the 1G8 in it now so that must work fine, been quoted Genuine kit for $220, just wanted to be sure there werent others that fit and/or are cheaper model varients,

what about the other stuff Dj any ideas _ what about your pre noughi barrell ? or you got more sexy jap parts tucked away ?

[Nathan S]

When its Yamaha 125 stuff, and its coming from Vandy or DJ, you should trust 'em Freaky!

I'll repeat: All of the early rods are the same. Yamaha supersceded all of the earlier YZ125 rods to the 125G (3R2) part many years ago, which should tell you everything you need to know.
The genuine DT rods are a bit chunkier but still fit straight in. If you buy an aftermarket rod for either a YZ or a DT, you'll get the same part.

HotRods don't have an awesome repuation in high stress motors (worked Banshees used in the dunes), but are still OK. I'd price genuine first.

To fit the 34mm forks, you just fit the 250/360 triple clamps. They go straight into the 125/175 frame.
DT250/360 lower triples are steel, while MX/YZ items are alloy. YZ125C lower triples also work, and are pre-75 legal as they're the same as YZ250B.
I want your original upper triple clamp if you go down this path.

I can't quite recall the casting numbers on the barrel... Pretty sure that YZ125A is 40102, while MX125A is 40100 (!?) - its cast into the RHS, near the intake manifold. In any case, the easy give-away is that the MX barrel has the port for the oil injection, while the YZ doesn't.
Remember that genuine YZ-A barrels are chrome plated, meaning no rebores and you MUST use the correct chome-bore-compatible ring (NOT just off the shelf Wiseco).
The pistons themselves are interchangable with all the YZ125s up to the 1985 model N. Yamaha has a zillion different part numbers because they were forever fiddling with ring numbers, widths, and intake cut-outs, but the pistons are 100% interchangable.

The dished alloy rear sprockets are still available, at a price. Most people use spacers and then fit (steel) DT175 sprockets.
The other option is to find a YZ125X rear hub/wheel and use it. Its basically an A hub with the spacer built in, so it accepts flat sprockets.
The third option is a YZ125D/E/F or monoshock DT125/175 hub, with a bit machined off the sprocket mounting face - these hubs essentially have an extra-thick spacer built in, so you need to machine them down to the X dimension.

[vandy010]

TY175 triple clamps are nice too! and the top clamp has a nice "lay~back" style to the bar mounts.
come to think of it, don't use them on the 125. but they are nice on the bigger bikes.

[albrid-3]

freaky, l have a dish alloy sprocket, 49 tooth

[Freakshow]

price or source please

[LWC82PE]

for rod kits have a look here. these guys have the largest stocks of rods of anyone i know. you can search through their data base now


http://203.59.136.171/search/index.php

or www.bbimporters.com.au

i just had a look and they have rod kits for 74 125 YZ yamahas Pro X part number for 74-79 - 03.2250 and part number for 80-85 YZ125 - 03.2203

you can confirm that on the website above or www.pro-x.com