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Blood Sweat Tears and Grease => Projects => Enduro / Dirt / Scramblers => Topic started by: runmikeyrun on Sep 01, 2016, 03:57:22

Title: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 01, 2016, 03:57:22
Well.  Finally scored one of these.  I've been looking for years for either the 250 or 350 (F5/F9).  Why? 

Back in the day my dad had a 350.  Sold it after a few years to a guy.  Fast forward to when I was 12 (late 80s) and dad bumps into said guy.  Guy sells the bike back to him, which has been sitting almost since my dad sold it to him.  My dad rebuilds the bike in our basement that year.  I watch and I'm hooked!  At 17 I bought my great uncle's RD250 and promptly restored it a couple years later.  I've been a vintage bike nut ever since.

About the project: the bike is an oil injected two stroke.  instead of going for a full restore my goal is to have a reliable and safe machine with the current "patina" that it has.  The tank and fenders are straight and while there's some of the usual scrapes, surface rust, tears in the seat cover etc its in pretty good overall shape for a bike that's 45 years old.  Besides I'm already balls deep in a cb350 frame off and two full restorations at the same time would be too much.  One good thing about the Ohio winter: lots of time to build.

I'll be working in two phases. 

Phase one includes getting it on the road before the Ohio winter.  Amazingly, the tank is spotless inside and it runs pretty strong!  Shifts nicely too.  So some quick safety upgrades are in order so I don't immediately die- check/clean brakes, replace tubes in tires, lube cables, fix trans oil leak, replace the crusty chain.  The petcock leaks like crazy.  Needs some bits to get back to street legal too:  gauges, head/tail light, signals etc.  It never ceases to amaze me the number of people who strip enduros of all these things!  Just buy a dirt bike.  Also, it needs a title so I'm working quickly to get the paperwork to Vermont BMV.

Phase two (next year) is a motor tear down for new gaskets, seals, clutch plates, etc.  Electrical upgrade (modern ignition and addition of regulator) and new tires.  The tires are workable in phase one and putting around town but for the sake of longevity they need replaced.  I'll probably replace all the control cables, fork seals, brake shoes, etc.  Wiring needs TLC.  Shocks are stock units and suck bad. 

At some point I'd like to swap the 250 cylinder and piston for the 350.  From what I've read the bottom ends and most of the rest of the two bikes are the same.  The 250 makes ~23 hp, the 350 ~34 hp.  Kind of a no-brainer.  I'll probably do this when I tear down the motor.

I decided to name her Buzz Bomb.  She actually has a deep grunt for a two stroke but still retains the buzzy quality they all have.

I'll post updates as I make progress!

Bike as she sits fresh after delivery- the beginning!(http://uploads.tapatalk-cdn.com/20160901/54c8c067c673cad6d7b614a9319e40e8.jpg)
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: advCo on Sep 01, 2016, 10:38:33
Sweet little enduro. I'm in for the ride


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Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: canyoncarver on Sep 01, 2016, 17:43:09
Yeah, I'm in.
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: jimmer on Sep 01, 2016, 18:04:54
I hope you keep the stock tank/seat combo with the original patina! Cool bike.
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: Hurco550 on Sep 01, 2016, 18:13:52
Cool! Watching
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 01, 2016, 20:08:41
I hope you keep the stock tank/seat combo with the original patina! Cool bike.
Yes, absolutely am!  People pay money to have their bikes relic'd like this.

Update: coincidence or fate that I start vacation a week after getting the bike?

(http://uploads.tapatalk-cdn.com/20160901/173b2c8d35d35591a877ef1741c2f065.jpg)

Tore into a couple things today.  First, I sent the bill of sale and DMV paperwork to Vermont to get a registration so I can get an Ohio title. 

Second, wanted to start addressing some issues and get the ball rolling on parts.  Ordered a battery, petcock and gauges online.  The Local vintage Kawasaki shop had a few items in stock- tail light lens, engine seals, and a chain.  I'm glad I bought a chain for one extra reason that I found when I got home:

(http://uploads.tapatalk-cdn.com/20160901/171c95b21d84a5d6124ab8a6aa72559a.jpg)

Seems as though a previous owner thought metal spade connectors would make good master link clips.  God, that would have ended poorly!

There's a transmission oil leak and a little investigation revealed it was coming from the clutch side cover.  Wouldn't you know, the bolts were loose.  Tightened those up, we'll see if it will address it enough until I tear down the motor.  While I was over there I inspected the carburetor which is under this cover:

(http://uploads.tapatalk-cdn.com/20160901/d24ce5219bd50d1398b37d5d34cd9213.jpg)

Everything was ok.  Replaced the fuel line while I was in there.  There's a plug missing that I'll have to find, because that's a direct line of unfiltered air to the engine!

Speaking of unfiltered air- the air filter element was long gone, so I oiled a piece of filter foam and wrapped the expanded metal cone.  I'm not sure how the bike was running, some doofus had installed the air cleaner lid so that it sealed the air cleaner assembly! 

(http://uploads.tapatalk-cdn.com/20160901/b38d30832327a4c296f1f45abce2c9ad.jpg)

The tail light socket is crusty because it's been missing a lens and bulb for who knows how long.  (http://uploads.tapatalk-cdn.com/20160901/adee5c12e4908a655cff9aed1a4d4c9c.jpg)

So I picked up a new center contact and will be installing that.  I couldn't find any 6v tail light bulbs locally, so I'll have to order some.

That's it for the moment, more to come!
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: jimmer on Sep 01, 2016, 20:13:36
Get on amazon.com and buy a 12$ JT countershaft sprocket for that new chain. I'm sure it needs a rear too. You are getting things done! Have a great and safe vacation.
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 01, 2016, 21:29:43
I think that's a great idea.  They look ok, bike's odometer says just under 3,000 miles.  But yes, I think sprockets are a solid idea
Title: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 01, 2016, 21:30:31
The tail light lens is reproduction, looks kinda funny all brand new and stuff.  Maybe I should hit it with a scotchbrite pad?  Lol

(http://uploads.tapatalk-cdn.com/20160902/decd60842079f3b2363eae20b5608990.jpg)
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: advCo on Sep 02, 2016, 03:00:46

The tail light lens is reproduction, looks kinda funny all brand new and stuff.  Maybe I should hit it with a scotchbrite pad?  Lol

(http://uploads.tapatalk-cdn.com/20160902/decd60842079f3b2363eae20b5608990.jpg)

Just throw it on the ground a couple times, that's the look I'm going with on the XL

JT is pretty good about getting you sprockets that will work, if they don't have your model just grab the measurements they show on the website and call them up. You can get em cheap if you shop around, I found the best prices for front and rear on eBay.


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Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: TranceMachineVienna on Sep 02, 2016, 04:48:08
I smell 2 stroke!count me in sir!
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 06, 2016, 14:09:48
Back from vacation.  I actually dreamed about working on the bike while I was away.  Two nights in a row.

Psychological issues aside, I got down to some stuff today.  I was smart enough to order a bunch of stuff before I left so I had some parts waiting for me.  I replaced the mangled gauges with some eBay units. 
(http://uploads.tapatalk-cdn.com/20160906/cec5c0c31bad3f78300d8d7b92868f69.jpg)
The new gauges came with the dash lights, which was nice because mine were corroded to all hell.  Stuck them inside some loom.  (http://uploads.tapatalk-cdn.com/20160906/0aef048e9073cebcb4ff28eef2a295e9.jpg)
Also lubed the cables and replaced a broken brake lever.  One of those fancy upside down units...
(http://uploads.tapatalk-cdn.com/20160906/016ed80c882ed13ae8252f1fcc080e79.jpg)
Speedo cable is shot.  Adding that and some gauge light bulbs to the list.

Found the source of my oil leak wasn't just a loose clutch cover.  Seems the shift shaft runs all the way through to the right side of the motor and out of the clutch cover.  The only reason I can think of this would be flat track, moving the shifter to the right side and removing the rear brake.  I've never seen anything like it before.  Anyways, the seal is shot so it's going on the list. 
(http://uploads.tapatalk-cdn.com/20160906/ca323521445f7973eabde3429374e183.jpg)
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: advCo on Sep 06, 2016, 14:18:18
Interesting setup with the shifter spline. Never seen that before either. Going to be able to save those forks?
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: julian.allard66 on Sep 06, 2016, 14:40:12
A few early Japanese bikes had gear change shafts like that so that the gear change could be on either side for different markets, the rear drum is usually on a cable as well so that it can be either side.
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 06, 2016, 14:58:56
Interesting setup with the shifter spline. Never seen that before either. Going to be able to save those forks?
The forks are ok in the travel area, so yeah. 
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 06, 2016, 14:59:27
A few early Japanese bikes had gear change shafts like that so that the gear change could be on either side for different markets, the rear drum is usually on a cable as well so that it can be either side.
Makes sense! 
Title: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 06, 2016, 15:51:08
No photos, but I pulled off the front wheel.  The front brakes and drum look good, reassembled and adjusted.  I left the fork oil alone; I am going to do the seals at a later date and I will change it then.

Done for the day.  Waiting on a petcock and battery and I need to find a headlight and signals as well.
Title: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 10, 2016, 00:22:08
Not too much today.  Put on the new petcock (heh heh) and since the screen doesn't fit in the tank I installed an inline filter.  I forget if it was Klemm's vintage or Junkman adv that had a link to the right petcock.  Anyways, it's a Biker's Choice chrome petcock for HD #011411 so I'm pretty sure it made my bike louder and lose 10 horsepower . I also rinsed the inside out thoroughly as there was quite a bit of rust on the old petcock screen.  (http://uploads.tapatalk-cdn.com/20160910/012f24b24cdc506cb2bf627ef7bf58a9.jpg)

Painted my recycled chrome turn signals with some plastidip.  I love this stuff.
(http://uploads.tapatalk-cdn.com/20160910/ffb10b846ffce6e3ab55c99a72bc2a10.jpg)

Horn was weak at best, so I checked the switch and it was crustified.  Sanded the terminals and spring and now works great. 
(http://uploads.tapatalk-cdn.com/20160910/ea505d69eb6ba10fa28ce2f11416a24b.jpg)

Ordered some headlight bucket ears, a 6v halogen bulb which I will Frankenstein into the existing sealed beam headlamp, and I'm working on clutch cover items- cover gasket and shift shaft/Kickstarter seals.  Oil leak was too bad to continue.  Will replace clutch discs and springs while I'm in there too, if I can find replacements.  I'm finding that there aren't many parts left out there for these.
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: jimmer on Sep 10, 2016, 09:23:10
Nice progress👍👍
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 13, 2016, 15:41:36
Tried to replace the crusty tube inside the 45 year old front tire today.  Tire itself was ok enough to ride out the last of the season but I at least wanted to have legit tubes in there.  Well the tires are as hard as you can imagine and the iron slipped, smashing my finger into the end of the axle.  As soon as I finished throwing the tire irons and swearing I broke down and ordered two new tires and tubes.  I will let a shop handle the swap!  (http://uploads.tapatalk-cdn.com/20160913/f6700cf2b534862e2e4f2f49fcb69c72.jpg)

On a positive note, all turn signals are installed and working.
Title: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 18, 2016, 16:01:08
Fuck that tire.  Mounted the front, waiting on the tube for the rear to come. 
(http://uploads.tapatalk-cdn.com/20160918/1f4b21dad3a6d61868b650e0af472e19.jpg)
Leaky seals in the clutch cover were replaced along with some new gaskets.  Scraping 45 year old gaskets, my least favorite lol.  Inside of the trans looks clean!  Put some oil in the transmission to check for leaks, so far so good. 

(http://uploads.tapatalk-cdn.com/20160918/0a751f0fe5a7711c6324dcdeed1105af.jpg)

I cobbled together a headlight from the old sealed beam and a 6v halogen bulb since the right size sealed beam was unavailable.  (http://uploads.tapatalk-cdn.com/20160918/a8073bf8926c17aa262ebec1dbc4318d.jpg)
Yes that's JB Weld lol. 

Still waiting for the plate/registration from Vermont.  It's been 18 days since I sent it and they haven't cashed the check yet so I figure it's in the mail on the way back with the correct amount due. 

I'm hoping to be on the road by tomorrow evening and hopefully legal in the near future!
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: advCo on Sep 18, 2016, 16:06:26
Sweet man. Where'd you source the 6v halogen I need to do the same thing for the XL headlight?

VT sent all my stuff back after a week because I went by the min sales price tax and they made me pay based off the "good" NADA value which is BS.


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Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 18, 2016, 16:11:37
I picked up the bulb on Amazon: 

OCTANE LIGHTING One - 6 Volt Halogen Headlight Headlamp Clear Glass Light Lamp Bulb 35/35W H4 6V https://www.amazon.com/dp/B00GNU2PJA/ref=cm_sw_r_cp_api_1yU3xbA6HZVNR

I should give them a call Monday, 19 days seems like a long time.  However, I'm not prepared to answer any questions like "why are you registering your vehicle here?" Lol.  I guess I can always just hang up!
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: advCo on Sep 18, 2016, 16:14:52
Nah they won't ask any questions, They just want your money, lol. I sent everything certified so I knew when they received it. They were pretty helpful when I called a couple times. Thanks for the link in the light


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Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 18, 2016, 16:17:49
Nah they won't ask any questions, They just want your money, lol. I sent everything certified so I knew when they received it. They were pretty helpful when I called a couple times. Thanks for the link in the light


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Awesome, I will give them a ring.  And no problem man!
Title: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 20, 2016, 02:06:54
Well, it runs.  It won't idle and it takes a second to spool up.  Pulls ok up to about 5,500 and then sounds like it's at a rev limiter tac-tac-tac-tac staccato.  Sounds like it's strangled or starved for fuel but choking makes it worse.  I'm thinking weak spark and/or timing issue.  The points don't look terrible but the condenser looks antique.  I have directions on how to set the timing but I don't have the corresponding photo- the directions say turn flywheel mark A to match mark B on crankcase then loosen screw E etc.  I have a good guess what it's talking about though lol.  Bummer that I've got to pull the flywheel to get to the points/condenser.

The headlight doesn't work.  I don't have juice at the socket or headlight switch, and applying power at the connectors near the ignition switch gives me nothing.  I did, however, apply power to the instrument lamp socket (which is in series with the headlight) and it lit up, so I'm thinking my ignition switch is bogus- it switches the headlight on/off.  It's mangled beyond recognition from too many years of being turned on/off with a screwdriver.  I have a replacement switch coming tomorrow so we'll see if that helps.
(http://uploads.tapatalk-cdn.com/20160920/e727757fcce65ee41a6d72da041d9d13.jpg)
I hope to mount the rear tire and service the rear brake soon, the latter of which contributes zero effort to stop the bike lol.

Wish I could just call off sick the next two days!  Lol
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 21, 2016, 19:42:39
Good news today- Vermont DMV cashed my check so it appears that my application was approved.  Hopefully in a few days I'll have a registration and a plate :D now if I can just get it running properly in time lol.
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: advCo on Sep 21, 2016, 21:34:26
You'll get your plate first, but probably have to wait a week or so for the actual registration and sticker.


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Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: davedogg on Sep 21, 2016, 23:22:00
Since it's a two stroke... check your timing and change those old crank seals before you give your piston a moonroof.
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 22, 2016, 00:36:38
Since it's a two stroke... check your timing and change those old crank seals before you give your piston a moonroof.
Good call.  I'll have the flywheel off to change the points anyways, and the other one is easy to access if I'm not mistaken.  Thanks for lookin out
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 22, 2016, 21:13:43
Well, buttoned up a few things today.  Checked ignition timing with a light, it's pretty close.  I cleaned the points with some 800 grit sandpaper.  I cleaned the carb really well and set all screws back to stock setting, they were way off of course.  I also discovered the head bolts were loose!  Torqued them to spec.  Installed the new rear tire and freshened up the rear brake.

I purchased a replacement ignition switch on eBay and to my surprise I found a matching NOS key from another auction. 

Old:(http://uploads.tapatalk-cdn.com/20160923/e2ed39b15482b310c7d16a3102e8e24c.jpg)
Yeah using a screwdriver sucks.  Well worth the $25 I spent. 

And... Got this in the mail:
(http://uploads.tapatalk-cdn.com/20160923/75de4e3da14276c59870ec98dd9ae43f.jpg)
I still can't believe it worked I will head to the Ohio BMV next week when the actual registration and sticker come.

So... It runs!!!!  Runs quite well actually.  It pulls pretty strong.  I think the clutch is slipping a bit.  I took a gamble when I did the new seals/gasket that it would be ok, because replacement plates/springs were $100.  Well, over the winter I'll handle that.  No biggie.  It will almost idle, i think it just needs to be ridden some more.  I rode it around the neighborhood for about 20 mins and the more I rode it the better it ran.  I put some B12 chemtool in along with some fresh gas from the pump.  We'll see how it goes.

When I get the points I will probably pick up the service manual for it, the place I go to has 3,000 manuals for sale.  If the crank seals are a bitch I will do them over the winter.  I'm debating dropping a 350 cylinder/piston into it anyways. 
Title: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Sep 29, 2016, 16:06:42
Well she's running pretty good!  Still won't idle but it's much better.  The more I ride it the better it runs.  Clutch seems to have gotten better too, it was slipping a little before. 

Tasks for the winter will possibly include a 350 head/barrel and corresponding jetting adjustment.  Possibly modifying the rotary intake disc.  Have to see what eBay prices are when the time comes.  Crank seals, points/condenser and possibly a voltage regulator. 

Quick vid of some light off road, nothing adventurous. 
https://youtu.be/3RlDPTMe8VE
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: canyoncarver on Oct 18, 2016, 22:13:51
That is pretty awesome.  Looks like fun riding wherever that is. 
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Oct 19, 2016, 01:11:24
That is pretty awesome.  Looks like fun riding wherever that is.
That was by my house, the area is quite small. 

Today's ride was at an abandoned brick yard.  The bike did well despite some electrical issues that took out all my lights, but who needs those in the woods.  (http://uploads.tapatalk-cdn.com/20161019/4ce70a60c47a26fb179b20c4149c5b5c.jpg)
(http://uploads.tapatalk-cdn.com/20161019/3b22348ad157a341ba10ce1289430405.jpg)

About 15 mins of the ride, choose HD.

https://youtu.be/Anzme860y4Y
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: advCo on Oct 19, 2016, 03:43:03
Looks like a blast. I sure hope I can find some trails like that near my new place.


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Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Oct 19, 2016, 19:01:20
Looks like a blast. I sure hope I can find some trails like that near my new place.


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I spent some company time searching google maps a few years back.  When I'm driving if I see a road going off into the woods or an abandoned factory I pull over and check google maps.  I've found quite a few spots that way
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: skinnej on Oct 16, 2017, 08:12:31
I just inherited this bike. It has the carb and cover in another box.
I was hoping you could tell me what its worth. I'm not a bike builder nor interested. I also inherited a Yamaha mx 360. The Yamaha runs and sounds great.
Can you help me with setting a price and where would be the best place to advertise it.

Thanks
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: skinnej on Oct 16, 2017, 08:14:26
here is the Kawasaki.
Title: Re: 1971 Kaw F8 Bison 250 goin' down.
Post by: runmikeyrun on Oct 18, 2017, 21:02:17
here is the Kawasaki.
I purchased my Kaw for $400.  It ran, shifted, etc but had no title.  Lots of issues that took me a couple months to sort out.  I'd say yours might be worth approx half that, maybe a little more or less depending on if the lights work, it has a title, etc.  If you can button it up and get it to run then you could ask more for it.  As for the yamaha, running condition gives it more value as does the apparent cosmetic condition being good, but not as much as some people might think because...

The thing to remind buyers is that ALL of these bikes need maintenance to some degree to get them roadworthy, reliable and safe.  I put about $800-1000 into my Kaw to get it running properly, fix safety issues, and get a title, which I was able to do through Vermont.  At the least they usually need carb cleaned and adjusted, points checked/adjusted, oil and gas changed, air in the tires, chain and cables adjusted/lubed.  I also disassemble the brakes and clean, clean out gas tank, replace rotting/leaking gaskets, replace tubes/tires that are any more than a few years old, check over all the electrical, way too much to list.  If a buyer does not know how to do these things then he is going to be shit out of luck, or he's going to pay someone a lot to do it if he can find someone to work on it at all.  And he's gonna have to tinker with things along the way too.  For those that can't wrench old bikes are a pain in the ass because they "always break down" when in reality they just need tlc.

Good luck!


Here's where I list all my bikes:
'71 Kaw 250 Bison
'81 KZ750 cafe
'94 XR250L
2014 Yamaha Bolt

In progress: '68 CL350