Vintage Dirt Bike Q & A

Does have a undamaged air box for sale? I have been looking for 3 years now and thought I found one in great condition. Sadly, all the changes Yamaha made back in the day during the same year produced this slightly wrong air box arriving on my doorstep. Are the light alloy replacements now my best option do you think?

I'm having the similar problem,(my bike is missing so much) I can't find solid info on what the deal is with the 78 yz250 air box and how it mounts? I paid way more than I care to admit for a really nice air box said to fit ,78250 but came from a 78 400. Problem is it fits the frame perfect but there no way to mount it. So further research i find the 77 yz has this weird air box mount but it works hand and hand with the motor mounts, and they are different 77 to 78 it's very hard for me to try and find pics of how it mounts

yes the 77 yz250 requires the large metal bracket which bolts to the underside of the frame. without it the airbox mount oints are in fresh air. I ended up bonding the broken box back together with some very strong glue. not perfect but work fine. Just now need a replacement airbox side cover and I should be OK.