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Modified BW80 Yamaha

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Discussion starter · #41 · (Edited)
Here's Sam's image. His vertical pieces might be taller than mine. The vertical pieces I used are 2" tall x 2" wide x 3/8" thick. This will give you about an 1 1/2" rise. You'll have to remove a piece about a 1/2" wide from both sides of the top clamp so the vertical pieces angle in at the top a little. They would look bad if they were straight up and down. Of course you could make the pieces taller or shorter if your looking for a different height, but i'm happy with the handling and looks.
 
Discussion starter · #43 · (Edited)
The shock alone does not raise the rear end. You need to drill the top shock mounting hole about 3/4" back from the stock mounting hole to raise the rear end. Once you do that you'll need a chain roller to help take up the slack created by raising the rear end.
 
#45 ·
There is a washer that is where the exhaust meets the engine that limits airflow resulting in a slower bike for younger riders. He should be fine if that is in there and when he needs more power then remove it. I wish I had one of these when I was 7 yrs old!
 
Discussion starter · #46 ·
Like Crawler said, excellent first time mini. I've put many first time riders on the BW80. Best part is the wide tires work great when the dirt gets soft, they motor right thru it. Stock power is mellow and I think there is a throttle limiter screw to keep it tame till he's ready for more. I actually bought mine back when the kid who was riding it outgrew it cause I missed having it.
 
#47 ·
234wheeler said:
View attachment 97299 Here's Sam's image. His vertical pieces might be taller than mine. The vertical pieces I used are 1 3/4" tall x 1 3/4 wide x 3/8" thick. This will give you about an 1 1/4" rise. You'll have to remove a piece about a 1/4" wide from both sides of the top clamp so the vertical pieces angle in at the top a little. They would look bad if they were straight up and down. Of course you could make the pieces taller or shorter if your looking for a different height, but i'm happy with the handling and looks.
Click to expand...
Thats what i did to my girls pw80 a while back plus i extended the shock mount on the swing arm and dropped the pivot point where the swing arm meets the frame an inch.
 
#48 ·
I have been thinking about using a piece of pipe with an id the same as the forks and attaching it to the under side of the tripletrees so I can change it back to stock when I want for my future kids. I don't think it would look bad raising the forks in your setup. What do you guys think or should I just "cut and paste" like we've been talking about? I also saw that you used one of those shocks and would like to know how/if/where you put a chain roller. I am still trying to decide whether I should splurge and buy the shock, just buy the extender or go the cheapie way and drill a new shock mount hole about an inch back.
 
#49 · (Edited)
I decide to go ahead and do it right. Will order the fastace 550lb shock next month. Working on the top clamp now, just trying to work out the minor details. From the pics it looks like the vertical pieces are 1/4" and not 3/8". I do have a few questions for 234wheeler if you don't mind. If you were to do the clamp again, would you still do the same rise or go higher? How and where did you install the roller? And how did you extend your kickstand?

I'm also in the process of putting the top end back together after cleaning it all out as well as the muffler. Hopefully it can breathe a little better now. The rings are a pain to compress with that odd shaped cylinder end. Also found a place that will mill the head for $40 so i'll probably go ahead and do that to. I dont think a port and polish will be that beneficial but I may do it later down the road.

I should have it all done by mid october.
 
Discussion starter · #50 · (Edited)
I'm happy with the top clamp dimensions. The 3/16" thick vertical piece is more than thick enough and much thicker than the top triple clamp itself. Also the cap on top of the forks clamps the fork tube to the top triple clamp. You can't slide the the forks up and down like most bikes. That's why you have to cut and lower the top triple clamp to raise the bike. I extended the kickstand by cutting off the pivot bracket, spring tab, and used a large washer for the foot and built a new kickstand using a longer piece of tubing the same diameter as stock. This is where it's nice to have a mig welder cause you can tack it together, put it in the bike and get it to lay up perfectly before you weld it up. I'll post a photo of the chain roller here soon.
 
#51 · (Edited)
After holding some 3/8" plate up to it, it seems like way overkill. Since I took 1/2" out of it, it makes it look like there is hardly any angle to it only having 1/8" gap from vertical. I am gonna see if I can scrounge up some 1/4". And 1n3/4" was too skinny so looks like I need to cut 1n7/8". Having a hard time just making sure everythings squared up. I would definitely like to check out your chain roller install. I'm finished with the whole engine, muffler and carb cleaning so I just need to weld the clamp up and get the shock. How did you keep your clutch cover from rusting after sanding?
 
#53 ·
Since the only welder I have access to is at school, this has taken a lot longer than I had hoped. I tacked it up, brought it home to make sure it would fit and it was way off. So I ended up using some quick glue and jbweld to "tack' it up and will weld it up tomorrow. Hopefully it wont warp if I keep it under 15v and rotate sides being welded back and forth. Then the plastics are off to be line-xed. Just need to get that shock and chain roller installed.
 
#55 · (Edited)
Wow! Nice fab job! I was thinking of making a bracket that extends down from the swing arm mount. Do you think that would work?

Edit: Finished, painted and installed the top clamp today. I was about to order the shock when I thought to myself, will this raise the rear "enough"? So I went out and measured the stock shock and sure enough, it is also 11" eye to eye. How high did the fastace shock raise the rear end over stock and if it is higher then why? I was looking at your pics but none of them are a side view where I can tell the height difference.

Image
 
Discussion starter · #56 · (Edited)
top mount

Those look good, nice work! I drilled a new shock mount 3/4" behind the original. This raised the rear end about 2". Here's photos of both sides of the top shock mount. The Fastace has more travel and a stiffer spring, much better than stock, especially for adult riders.
 
#57 ·
Im the new guy here. This is an awesome thread!
Time to share my story too.
I just bought an '86 BW80 for $300.
It belonged to a family friend, who's kid's I grew up with. They've had it since day-1. I even rode it a few times as a kid. Now, we're all grown up and "almost" too big to ride it.
In reality, it hadn't been used in several 5-8 years, was collecting dust and rotting away. So, they got it fixed up and running again and were looking for a good home for it to goto. I heard through the grapevine they were looking for a good home, and I have a good home and kids that will (eventually) ride it. My kids are 5 and 2.5 now. They WILL ride it within a year or 2.
Anyway... at a recent family holiday BBQ, I talked to them about and said that "I have a good home for it to goto." He told me they just spent $300-ish getting it running again (new carb, new grips, throttle tube & cable, oil change, air filter) and don't want it to sit around any more. The only thing it was missing was the muffler.
$300 later I bring it home. The best part, for me, is that not only did I dream and hope and wish to pray and beg to have one of these when I was 8yr old, but I rode THIS ONE several times, and now own it for me ...er my kids to enjoy!
Here's what I can tell about it so far.
Everything is stock!!
Oil injection still works.
Original cylinder and piston.
Original plastics and seat.
Original foot pegs.
Original pipe and muffler (err... where there should be a muffler)
Some quick browsing through this thread to educate myself and $101 E-bay dollars later, I have a Chineese knock off pipe and muffler.
YAMAHA PW80 PW BW 80 EXHAUST SILENCER MUFFLER PIPE EX23 | eBay
This will at least get me legally running and registered for some 'trial runs.'
So, just wanted to share what I got and share what repairs/restoration I'll be doing on it.
Image

Image
 
#58 ·
Suspension rebuild and Shop Manual question.

Has anyone on here done their own front fork rebuild?
Any tips? Tricks? Special tools required??

Also, is the Clymer PW80 Repair manual good enough for a BW80, or are there enough subtle differences between a PW and BW? Im thinking specificaly regarding front and rear suspension rebuilds.
 
#59 ·
You can get a bw80 repair manual download or cd online for about $10. I have found free owners manual and parts list pdf's free online. I believe that the older model pw80s engines are pretty much identical but not everything is the same. Many people use the pw80 clymers manual but there are other options.
 
Discussion starter · #60 ·
Thanks BIG, you got a great deal! The BW80 is a great kids mini. If the bike has to sit at all then drain the carb. The carb has tiny jets that plug easily. Also check PWonly.com for things like pegs, bars, etc. A lot of PW80 parts work on the BW80. The stock pegs suck so I would change those to steel pegs, but other than routine maintenence i'd just enjoy....
 
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