'82-'83 175 pistons...long story.

This is a synopsis of my almost 2 year search for parts and information on the '82 Husky Products 175 kit pistons and the '83 production pistons.
In Dec '10 I bought an '82 XC125 that had the entire Husky Products 175 kit. As many know, the 175 kit included a pipe, cylinder, head, exhaust manifold, and a cylinder base spacer plate. The large oval intake holes on the '82-'83 (and probably up to '86 which was the last true Husky 125) piston makes them easy to identify, no other piston looks like it. I have bought 10+ '82 175 pistons on eBay that were either not labeled as for a specific year, or mislabeled as for the '76. The piston sizes are confusing though. The stock bore for the '82 175 is 64.75mm but all of the pistons I have stamped "cs" on the top indicating stock size are far too small, like .5mm or more too small. I have an unused NOS '83 175 cylinder so I know for certain the bore is stock, but these pistons can NOT be for another bike, they are too small for the '82, but are definitely not for the '76 175 which had a standard bore of 62mm and the '76 wrist pin is bigger than the '82. I have some pistons marked 64.88mm which are marked as 4th over, that is closer to 1st over but a 1st over should be 64.96mm not 64.88mm., yet they are identical in every other dimension to the piston that was in the '82 kit cylinder when I got it. I now have 5 of those 64.88mm pistons, and my '82 kit cylinder needs to be bored so I am thinking of sending it to Lancort or somewhere else and have it nikasil coated to that size. 4 OEM Mahle pistons should last me a lifetime of Vintage use as long as I keep the air filter clean.
Last month I bought an '83 WR175, the production bike. There are some interesting differences in the kit parts and the production parts. When I first looked at the bike I was a little bit concerned that it did not have the base spacer plate, I was worried I had bought a 125 that was claimed to be a 175. I popped the head off and measured the bore and it was indeed a 175 at stock size. Obviously the '83 piston had to be different than the '82 kit piston if it did not require the spacer plate, the wrist pin compression height had to be different, or the rod had to be shorter. Since Husky treated the 125/175s like step-children I suspected a different piston over a different crank/rod. I was in a hurry to get other bikes ready for Unadilla so I didnt take the cylinder off. When I got back from Unadilla I popped the cylinder off and the '83 piston is indeed much shorter with a pin height closer to the crown. The '83 cylinder does not use the larger exhaust manifold like the '82 kit either, it uses the same size manifold as the 125. Another interesting difference in the kit top end and the '83 production top end is the iron "lip" at the top has a larger outside diameter on the '83 than it does on the '82 so that the '82 kit head will not fit the '83 cylinder without either the liner or the head being machined. Since I have both a kit head and an '83 production head I wont have to do that, but its interesting.
At Unadilla I talked to Husky Guru Craig Hayes and he said the original Husky Products 175 piston was an off the shelf piston from some other brand and model of bike, Husky did not make it. The piston they used for the STD size of the kit was actually the unknown bikes 1mm oversize, which explains why the pistons I have with .040 (1mm) in the top fit the NOS '83 cylinder I have.
I am glad I discovered that the '83 piston was different and allows the use of the 175 cylinder without a spacer plate. I will still have some 175 pistons made, but I will send the '83 as an example instead of the '82 so that anyone wanting to build a 175 will not have to find, or have made, a spacer plate.
Brian

I have a 175 head and cylinder with a broken sleeve .
Don't know if it is a 82 or 83.
Could you send pics to show the differences between 82 and 83 ?
Thanks

'82 cylinders were bare aluminum, '83s were black.

I have an 82' XC with the 175 kit installed with no spacer. Is this in line with what you have found? This thing runs great, but I would like to know what to look for when it comes time to do a top end.

Without the spacer the kit piston will hit the cylinder head before it reaches TDC. The kit piston is 5-6mm taller, I dont see how it can be used without the spacer under the cylinder. Are you sure it does not have the spacer? Maybe it has an '83 piston? The '83 piston has a completely flat top, where the kit piston is domed. Here is a pic of the kit piston on the left and the 125 piston on the right with a wrist pin in them to set compression height.



An update on pistons, there are several rods that will let you bump up to a 16mm wrist pin and access all kinds of pistons like Yamaha Banshee, IT200, KTM200 etc that are the right bore size or very close. One of those, particularly the ones for the Banshee stroker crank, look like they will work. I think it might be easier to change a rod and use an off the shelf piston instead of having a small batch of '83 style pistons made.

Hello Kartwheel 68
I'm writing to have some more informations about the 175
you seems to know a lot.
I have measured the outside diameter of my 175 lip liner.
It makes 76 mm. Is it a 82 or a 83 cylinder ?
How much is a 83 lip liner ?

Can we find 82 or 83 liners ?

About the 82 175 cyl: Is it a 125 cylinder bored with a bigger liner by HP
or is it a 175 cylinder made by the factory ?

Is the 83 pipe the same on 125 and 175 ?

Can a HP '82 pipe can fit on a 83 cylinder ?

What size are the piston pins on banshees ?

Thanks

Michel

If you needed to replace a rod, you could use a shorter rod as you know. I have found you can likely find something you can lightly modify from Hot Rods catalog .I was able to find rods from them that could be used with minimal modification for both the 135mm rod used in the 82 up 250, 430, 400 and the 145mm rod for the 500 2T

The Husky 125/175 rod is already too short, I am looking at using a 13mm longer rod with a 1mm bigger small end to allow use of the Yamaha pistons.

Michel,

76mm should be an '82 kit cylinder, the '83 is 83mm outside diameter. I dont know if there are any liners available.

As far as I know, the '82 kit cylinder was just a 125 with a bigger liner, while the '83 was a purpose built 175 cylinder, the castings are different for sure.

The '82 kit came with a special pipe that used a bigger ID exhaust manifold, the '83 175 used the same pipe/manifiold as the 125.

You can use the '82 pipe on an '83 cylinder if you also have the bigger manifold.

The the Yamaha pistons start at 64mm and go up to 66.5mm, the STD Husky 175 piston is 64.75mm.

You can search product on Hot Rods website for the rod with the exact center to center distance you need. You may need to make a step pin for the big end and possibly shave or shim big and small end widths, but you are looking at a custom installation so that is what might need be done

I already found a rod with the correct big end and a 1mm+ small end, I just have to buy one and determine the correct thickness cylinder spacer for the new rod/piston combo.

hello have you some news about the 175 story.
do you think is it possible to put a 175 sleeve on the 83 125 cylinder?
sincerely
@+fred

There was an old Husqvarna dealer in Stratford,ct I haven't been there in over 15 years. I'm not sure if he's still in business or alive. He would have the knowledge or the piston you need. There's lots of out of business Husqvarna dealers who hung on to there parts. Kart, email sent.

piston NOS OEM
65.19 mm
175/1983
ebay usa
for sale
299 $ us

Didn't the older 250cc mag engine use a shorter connecting rod with a 250cc piston? I remember rebuilding one once. Does the 125/175 use the same short connecting rod? With the same tdc height on the cylinder?

no

hello kartwheel
have you done some modification with new rod and piston
what is working well with the 175 cylinder
someone have the carb jetting for the 175 83
sinvcerely
@+fred

I stopped working on the project because no one was interested in it other than me.

sorry for arriving to late
i have the plan to build one
some news in the few days
@+fred

receive some parts to upgrade a 125 hva 1983 to an 175
piston 64,75mm and cylinder with new liner
don't have a 175 head
if someone have one i will be interested or will copy it to another 125 head
@+fred