RD400 chain length confusion

[ElFuegoBlanco]

I ordered a replacement 530 chain for a '76 RD400 cut to stock RD400 length from Economy Cycle
The chain was cut to 96 links and it's too short. The chain I replaced is 98 links. Can someone help me figure out where I went wrong here? The rear sprocket is has 38 teeth, if that helps at all. Even with the rear wheel all the way forward, I'm 2 links from being able to connect the ends of the chain.

Rob

[Striker1423]

Easy answer, you got an rd350 chain length.

[rodneya]

Easy answer, you got an rd350 chain length.

Nope, according to Economys site the 350 is cut to 92 links and the 400 to 96 links.

Do you still have the stock swingarm?

[ElFuegoBlanco]

Easy answer, you got an rd350 chain length.

Nope, according to Economys site the 350 is cut to 92 links and the 400 to 96 links.

Do you still have the stock swingarm?

It was a barn find, so... Yes? As far as I know.

[1976RD400C]

Did you count the links, maybe it was cut wrong?

[ElFuegoBlanco]

Did you count the links, maybe it was cut wrong?

Yep. Old chain: 98. New chain: 96

I have found 96 in several places, including the parts diagram. But then I see 98 in posts like https://www.aircooledrdclub.com/smf/index.php?topic=51468.msg404047#msg404047 and I don't know what to think

[1976RD400C]

Does it have the proper adjusters allowing the axle to move all the way forward in the oval holes in the swing arm? 

[Jspooner]

Just throwing this out there but could there be some confusion between the number of links with a 520 vs a 530 chain?

[ElFuegoBlanco]

Does it have the proper adjusters allowing the axle to move all the way forward in the oval holes in the swing arm? 

The wheel is all the way forward, yeah

Just throwing this out there but could there be some confusion between the number of links with a 520 vs a 530 chain?

All of the chains I see on economy's website say 96 links for the rd400. 520 and 530 alike.

[SoCal250]

Did you count the links, maybe it was cut wrong?

Yep. Old chain: 98. New chain: 96

I have found 96 in several places, including the parts diagram. But then I see 98 in posts like https://www.aircooledrdclub.com/smf/index.php?topic=51468.msg404047#msg404047 and I don't know what to think

96L is correct for RD400 (USA 1A1 & 2V0 and for CAN 1A1 & 3J7)
THE TECH LIBRARY »TRANSMISSION - CLUTCH - FINAL DRIVE
Not sure what model that post on the A/C site is referring to because the UK/EU 1A3 & 2R9 also uses a 96L.

Maybe post some pictures of what your parts look like.

[ElFuegoBlanco]

I'm not sure what pictures would be helpful. If you have any suggestions, please let me know.
Rob

[SoCal250]

That swingarm doesn't look stock.

Should look like this. Notice the axle slot plates
https://www.ebay.com/itm/Yamaha-400-RD-RD400-Used-Swingarm-1976-1977-ANX-B-54/154129701988
https://www.ebay.com/itm/1977-YAMAHA-RD400-REAR-SWINGARM-SUSPENSION-ARM/312174166393

[bostontrackrat]

This is very interesting.  I have an RD350 and bought the 92L (520) chain from them, and it was 2 links too short as well, even with the adjusters cranked all the way forward.  I'm returning it and getting a 100L chain and cutting it to my needs.

[Economy Cycle John]

RD250/350 is 92L
RD400 is 96L

520/530 are same length only width is different. 400 swinger is 1" longer.

[ElFuegoBlanco]

That swingarm doesn't look stock.

Should look like this. Notice the axle slot plates
https://www.ebay.com/itm/Yamaha-400-RD-RD400-Used-Swingarm-1976-1977-ANX-B-54/154129701988
https://www.ebay.com/itm/1977-YAMAHA-RD400-REAR-SWINGARM-SUSPENSION-ARM/312174166393

I don't quite understand what you mean. I'm not seeing the difference you're referring to between the ebay swing arm and mine.

The swing arm measures just shy of 20 1/4" (best I can measure while installed, anyway) and the rear sprocket is right around 8".