YZ125 1979

[gsr]

Hi all,
I am in the middle of putting together a bitsa motor. Yz125 79 top end on a dt175 bottom end.
I want to upgrade the intake and put a different carby on it. Does anyone know if a reed assembly from a YZ125 95-04 will fit? Also looking at putting a pwk flat slide carby on it, any info would be great.
Cheers

[Nathan S]

I think later YZ85 reed blocks can be made to work.
No reason why a PWK wouldn't work. I've got the measurements of the two larger body sides written down at home - will get them this arvo if I remember.

[gsr]

Thanks Nathan, any info is appreciated.

[Viper666]

Yz125 79 top end on a dt175 bottom end.

Almost a YZ125D\E. You could run their electrics but I assume you want the flywheel for torque?

[gsr]

Hey Perko,
Yep running the DT electrics for lighting and a modified flywheel, weight is about halfway between Yz and Dt. Also looking at doing a bit of porting work for a bit more power spread.

Cheers
Alex

[gsr]

Ordered a couple of reed valve gaskets off various Yz models.
I figure this will be the easiest way to see what will fit 

[Nathan S]

They didn't change much. In the 1970s, there's basically one YZ125/IT175 pattern, and a DT125/175 pattern.
Late YZ80/85 is probably the most helpful.

[bruce g]

not sure that this will help
restoring a DG themed 1982 YZ80 with a heap of engine mods running a V Force 3 reed and 32mm flat slide
have done some research on reed block sizes the early CR125 honda reed block has the same bolt pattern but slightly bigger in the reed cage so it will fit the YZ
for the YZ80 barrel had to grind out the sides of the port to fit the Vforce reed and had to run a reed spacer
early 80s yz100/125  have the same size bolt patten on the reed block
so if you want your YZ to rip good fit a Vforce reed and flat
heres some pics
cheersslide

[gsr]

Hi Bruce,
Where did you find the v force reed block, and is it a Yz one?

Thanks for the pics and info.

Alex

[bruce g]

Hi Alex

1987 to 2002 CR125 Honda { V301A V Force# number}
have to use a reed spacer and have to relieve out the sides of the port on the barrel
and it will fit have done it my little YZ80J and im pretty sure yz100 125s have the same bolt pattern as the 80
check the pic out shows both reeds and barrel
cheers
Bruce

[fred99999au]

You might need to grease that v-force reed block as well.

[tony27]

Would the reed block that fits the later yz80/85s not fit without modification, have a v-force 1 sitting here that is going into something else that I can measure up if you want

[bruce g]

heres a drawing with specs for standard yz80 J reed 1982 model
hope it helps
cheers
Bruce

[tony27]

V-force for YZ85 is V382S-A, this has a manifold as well but may not be needed, this kit also has centralized stuffer rather than offset

Mounting holes are 48mm x 58mm centres
Block is 47mm long, 44mm wide & 37.5 high & 15mm wide at the tips

That's quite different to the later stuff

[bruce g]

Did a fair bit of checking with different Vforce reeds on yzs, kxs,ktms,rms, ranging from 80s to 125s
have the upper hand as the Vforce importer is just up the road from me in my workshop in Tullamarine, and i sweet talked the office girl into giving me the where-house dudes phone number
in turn he let me come into the factory and pull out the actual reeds so i could measure them
thats how i came up with the CR125 reed which is real close to the early yz
sorry for the slow reply but i am trying to finish off my XR200 so i can enter it for this season
wont make the first one at Krusics
but should be ok for Pakenham