Author Topic: 1979 YZ 250 and YZ400 frame differences  (Read 2334 times)

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Offline loosecannon

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1979 YZ 250 and YZ400 frame differences
« on: February 13, 2014, 09:20:11 am »
Hi guy's

I just checked the numbers on my 1979 YZ250 frame, and it's a YZ400 number, is there any differences in the frames?, I have been told there isn't

Would this cause any dramas come time to race it in any classes , once I'm ready to race it, I haven't raced yet, so I just thought I would ask

Regards
Dave

Offline vandy010

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Re: 1979 YZ 250 and YZ400 frame differences
« Reply #1 on: February 13, 2014, 10:17:21 am »
I'll say no drama at all Dave,
frames are from the same year (evo) and the engine size
decides what class it runs in..
No probs...
I have a swing arm and airbox to suit the 250/400F if yourself or anyone
reading this is interested...
Cheers,
Vandy
"flat bickie"

Offline loosecannon

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Re: 1979 YZ 250 and YZ400 frame differences
« Reply #2 on: February 13, 2014, 03:52:06 pm »
Thanks for the info Vandy ,

I did read somewhere they are the same frame, even part number with Yamaha,


Regards
Dave

Offline Viper666

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Re: 1979 YZ 250 and YZ400 frame differences
« Reply #3 on: February 17, 2014, 08:19:17 pm »

Frames are identical. The only differences between 250/400F is the engine (obvious), pilot, needle, main jet & slide in carby & tube from carby to air box (400 shorter), expansion chamber, CDI & spark plug coil. (250 use magneto, 400 flywheel), rear rim & spoke set (250 2.15 rim, 400 2.50 rim) but you can use either.

Thank the Lord for Melbourne Bitter, anti-inflamatory drugs & an understanding wife.
YZ80H, YZ100G, YZ125E, YZ125F, YZ125G, YZ250D, YZ250E, YZ250F, YZ250G, YZ250H, YZ400F, IT125G, IT250K & a, a, a,      CRF250X???????    

How the FUG did that sh*tbox Honda get in here?

Offline loosecannon

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Re: 1979 YZ 250 and YZ400 frame differences
« Reply #4 on: February 17, 2014, 08:25:21 pm »
Thanks a bunch for the info Viper  ;)

I did hear they were the same, but wanted to confirm it, incase I needed different parts...anyway mine will be a race bike, not a concourse/show bike, the fact the frame number is different won't make a rats to me, I only want to race it

Offline Viper666

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Re: 1979 YZ 250 and YZ400 frame differences
« Reply #5 on: February 17, 2014, 08:29:07 pm »
If you were to buy a new frame, back in the day, it wasn't stamped. I have new cases for my YZ125E & it so you can restamp your own.
Thank the Lord for Melbourne Bitter, anti-inflamatory drugs & an understanding wife.
YZ80H, YZ100G, YZ125E, YZ125F, YZ125G, YZ250D, YZ250E, YZ250F, YZ250G, YZ250H, YZ400F, IT125G, IT250K & a, a, a,      CRF250X???????    

How the FUG did that sh*tbox Honda get in here?

Offline loosecannon

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Re: 1979 YZ 250 and YZ400 frame differences
« Reply #6 on: February 17, 2014, 08:37:28 pm »
Ok, cool that's interesting to know too  ;)

one more coat of paint and you won't see my frame number anyway...lol...