GS tuned

[MattyQ]

I recieved two tanks with my 74 125 , one says GS Tuned.  I tried to do a search to see exactly what that meant.  Sounds like it was just a sticker KTM put on the bikes that year.  Was that the case ?

Q

Matthew Quinlan

[tomale]

Matthew, it is not just a sticker,there is a difference. These Pentons  are a rare breed indeed, to my knowledge it is the only bike that actually is set up to actually allow you to change the the port timing/compression ration and ignition timing. the way it is done is by adding or removing cylinder base gaskets. This is measured by "deck height" check your manual for a better discription of what this is and the second is by either advancing or retarding the timing. when used together it can take a bike set up for the quickness of Motocross and detuning it to make it more rideable in the woods... Ie more trottle control making those tight woods section alot easier to manuever. John Penton really knew what he was doing.....  I should have the specs but I will have to dig for them....

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)
75' GS400 (finished project bike)
72'sixday (project bike)

[TGTech]

Matty:

The letters GS stand for GelandeSport, which in English, is basically, Enduro Tuned. Since at the time this came about, the Pentons and KTMs, were primarily used for enduro use, this just meant that the engines were tuned a little more for enduro use, than just general usage. There was a little bit of port work done to the engines, but it wasn't all that extensive.

Dane

[OUCWBOY]

Normally the GS tuned stickers were placed on the engine cases and not on the tank. Your bike may or may not be a GS bike. Count the fjins on the cylinder. If it has 6 fins, it is a "D" cylinder and if it has 7 fins it is a "B" cylinder.

Donny Smith
Paragould, AR

[Rain Man]

I know where you can get some DW tuned stickers

Raymond
 Down East Pentons

[socalmx]

GS or DW Tuned might have been nice but it would be very hard to top sporting a Mettco or FMF (in my case) sticker on your bike. Uncle Donny did the porting himself on my DKW 100B engine in 1974. That was one fast bike, wish I would have kept it.

[bkinnon]

I have a Jackpiner that has a Mettco decal on the tank. What can I look for to see if it has more than just the sticker? I bought it several years ago and, as Raymond knows, I have put it to one side and not touched it since.

Downeast Pentons- Central Division

[MattyQ]

I have 7 fins on my cylinder so is the B cylinder considered GS tuned ?  The tank looks to have an original GS sticker and may be the additional tank I received with the bike .  

Thanks for all the great info!

Q

Matthew Quinlan

[rob w]

Matthew,

The blue and white, long and narrow "GS Tuned" decals that Donny is talking about, were on the side cases.

but.....

I think you're refering to the red and chrome, almost square "GS Tuned" decal. Which was indeed found on the gas tanks just above the "Six-Day" decal.

I think Randy K. has new remakes of both of them.

You'll only find the red GS tank decals on Penton's of a certain time period. I want to say maybe late '73's thru '74's....and I'm pretty certain, on 100's and 125's only.

Have a good day,
BobW

[socalmx]

Any bike sold by Mettco had the sticker on the gas tank (as well as the rivets). If the engine had been tweaked, you could tell by looking at the intake spigot. It would have been ground open as far as possible. Another indicator is that the head would have been milled (up to .060)to the point where the head gasket surface was almost flush with the fins.