1980 Yamaha YZ250 weight savings

jrfx41
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jrfx41
Edited Date/Time 1/4/2021 10:19am
I've heard that is fairly easy to shed 10 lbs on the 1980-81 YZ250's by replacing steel nuts and bolts, wheel spacers, handlebars, and kick starter. Anyone know what make, model, and year aluminum kickstarter will fit? Same question for the wheel spacers. Thanks and much appreciated.


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OldPro277
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OldPro277 1/3/2021 4:20pm
1/3/2021 4:20pm
As an FYI- I built a 1980 YZ250g that weighs 204.8 lbs with oil (no fuel). There are a ton of things you can do. Alum.Wheel spacers are easy to make, pull out your wheel bearings and make the bearing spacers out of aluminum and drill the shit out of them. Aluminum bolts everywhere there’s no stress and titanium everywhere else. Cone pipe and alloy silencer will save almost 5 lbs alone. I turned my hubs down a little, used motion pro ultra lite rim locks, ultra light bike master tubes and Pirelli MX32 tires, another easy almost 2 lbs was to retro fit a 78 YZ125 fuel tank , slimmer ,much lighter and looks “OW” works,alloy rear sprocket and rear torque arm., I got it to that weight without titanium axles or mono spring , and I also used 82 43mm forks with trick billet clamps and a DLS front brake setup,and an inch longer swingarm from an 81 . I have all the weight savings logged in a “build notebook “ I’ll try to pull it out sometime this week
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jrfx41
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jrfx41 1/3/2021 7:02pm
1/3/2021 7:02pm
Thanks OldPro277! This is exactly the info I was looking for. I've already done a few of those tricks... cone pipe, alloy silencer, alloy handlebars. I'll start with the low hanging fruit that you listed...rim locks, tubes, no stress aluminum nuts/bolts. Had no idea you could shave off 2 lbs with tank swap. Would love to get my hands on your "build notebook"!
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rob.boucher.547 1/4/2021 6:58am
1/4/2021 6:58am Edited Date/Time 1/4/2021 6:59am
Yes, 10-15 lbs easy


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rob.boucher.547 1/4/2021 7:03am
1/4/2021 7:03am
many hand made items, exhaust hangers
silencer, dozens of hand made ti fasteners





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rob.boucher.547 1/4/2021 7:13am
1/4/2021 7:13am
I do not have pics of the chain adjuster spacers, or front or rear axle spacers, over a pound of savings there, cut of the kick stand
mount, remove the steel bars, brake arm
seat brackets, steel shock collars
steel res cap( made custom billet res parts/hose kits


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rob.boucher.547 1/4/2021 9:21am
1/4/2021 9:21am Edited Date/Time 1/4/2021 9:23am
I do not recommend the answer silencer
it will melt your panels, i made my own
and made sure the pipe to silencer tube
and a better bend to clear the side panel
by at least an inch
Remove all the steel bushings/washers
fuel tank mounts,airbox mounts also
head stay bolt
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jrfx41
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jrfx41 1/4/2021 9:32am
1/4/2021 9:32am
jrfx41
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jrfx41 1/4/2021 9:38am
1/4/2021 9:38am
Holy #!@$! That thing is every bit as trick...maybe more so... than an OW! Nice job. Is that an '83-'87 rear brake stay arm that has been drilled?
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OldPro277
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OldPro277 1/4/2021 9:45am
1/4/2021 9:45am
jrfx41 wrote:
Thanks OldPro277! This is exactly the info I was looking for. I've already done a few of those tricks... cone pipe, alloy silencer, alloy handlebars. I'll...
Thanks OldPro277! This is exactly the info I was looking for. I've already done a few of those tricks... cone pipe, alloy silencer, alloy handlebars. I'll start with the low hanging fruit that you listed...rim locks, tubes, no stress aluminum nuts/bolts. Had no idea you could shave off 2 lbs with tank swap. Would love to get my hands on your "build notebook"!
I'll do my best to get it out of the files, and possibly send some pics of the "Classified Top Secret Eyes only" mods, lmao. Its a great bike and only gets better with the weight savings. I believe I could get that bike to 199 lbs ready to race if I wanted to spend a ridiculous amount more , but other projects are taking priority at the moment.


FYI--- I have an extra stock plastic 78 125 tank, as I upgraded mine to an alloy replica. The smaller tank REALLY improves the look of the bike in my opinion, and it takes the weight off at exactly where its needed. Since our Vintage races are never any longer than 20 minutes, the smaller capacity is never a concern.
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OldPro277
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OldPro277 1/4/2021 12:24pm
1/4/2021 12:24pm
Shawbridge Husky wrote:
I came across this alloy replica on eBay, they make for 125D-E and 250D-E :
https://www.ebay.com/itm/Petrol-Gas-Fuel-Tank-Aluminium-Fits-Yamaha-YZ1…
Watch those dudes. I sent them 2 plastic OEM tanks for "patterns" and I never got them back OR my alloy tank. But apparently they put my tanks to good use,since they are now offering 78 YZ tanks, lol. Bastards !!!!
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