Kent Money's First Build - "Beginner's Luck"

KentMoney

XS650 Addict
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I had written a nice intro and then the page just refreshed on its own !:banghead:


Anyways, this is my first automotive endeavor so the learning curve was a little steep. I come from a BMX background (I rode for about a decade, check it out here) so it was only logical that I would progress onto custom motorcycles after I stopped riding BMX bikes in college.

So, here is my 1981 XS650 Special as I bought it about 2 months ago. 13,000 miles on it for $1200 (pretty good price in California!). The previous owner had rejetted the carbs and put on pod filters and drag pipes, but other than that it was pretty stock. I actually bought it before I even had my M1 license, so as soon as I got it I was riding it stock for about a month. Here is how she looked.

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Then, I bought some new drag bars an lowered the rear suspension a bit. I rode it like this for about half a month before I started to get reallllly fed up with the stock charging system and other various electronic disappointments. But everything else was riding pretty damn good I think!

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So, I finally said "fuck this!" and started tearing her down.

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I pretty much got her all disassembled in one evening. Then after about two days of chopping and grinding various crap off the bike, it was starting to look like this.

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So I was making pretty good progress in those three days but that's when things started to slow down. I decided that I was going to 277 rephase this sucker and do a total engine overhaul. I researched my ass off and finally got the confidence to dive in.

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As expected, the sump filter was torn :shrug:

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Then I started to mess with the crankshaft to rephase it. I really don't have any serious machinery, just basic power tools so i had to improvise. I saw that someone else had split the crankshaft like this so I gave it a shot, worked like a charm :)
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Success!
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I ground out a notch for the sprocket key and this baby is ready to get pressed back together. I am going to have to outsource that task, however, as well as truing to a local machine shop. In the meantime, I am going to start cleaning up my engine cases for painting and polishing.

I also found that the cylinders are ovaled, so I will be going with 1st oversize piston/rings and I will have the cylinders bored and honed.

Here is how the chassis stands at the moment. I personally sorta like soft-tails better (I know, a minority) so it's gonna keep the suspension. I mounted the sporty tank and some other crap. I plan to do a cafe-style seat faring/fender, I think it's gonna look really good. I may also go for some slightly higher Z-bars if I can find a good set in 7/8. I think im going for a bobber/brat/cafe fusion style.

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That vimeo video is dope, you've got some serious riding skills. Skateboarding was my addiction for about 15 years.

Build is looking really good! I agree on the suspenstion, like it much better with it.
 
how much effort was it to turn those bolts to get the crank apart? like , he-man, or pee-wee herman?
 
I tried the bolts to get my crank apart. Busted my butt and got nowhere. Used a twenty ton press. No problem.
I heard you can do about the same to get them together. Get some 1/2 thick steel. Drill matching holes in the steel just a bit farther apart than the flywheels are in diameter. A couple long bolts through the holes. Slide the steel between the flywheels by the rods, Center over the center pin, tighten the bolts.
I don't reccomend either the bolt trick or the clamp trick. I have built a couple cranks with a 20t press. I would reccomend that and welding the crank. When I rebuild the crank for the 750 rephase, thats how it will be done.
I'll probably let Hugh at Hugh's Handbuilt do the crank and cam. For it.
Leo
 
Looking good man. Nice to see another bay area builder.

Thanks man. You got a sick garage shop yourself. I'm really trying to connect with other Bay Area riders, so lets definitely plan to cruise when I have this thing up and running! i wanna check out your shop too.

That vimeo video is dope, you've got some serious riding skills. Skateboarding was my addiction for about 15 years.

Build is looking really good! I agree on the suspenstion, like it much better with it.
Thanks for the props man. I've done a bit of skateboarding and longboarding too, fun stuff.

:cheers: on the softtail

how much effort was it to turn those bolts to get the crank apart? like , he-man, or pee-wee herman?

I'm not that weak, but I'm not he-man. I just used the two crescent wrences you see in the pics and pulled them in opposite directions. The handles did start to hurt my hands after a while from the force, however, so I used a PVC cheater bar to help alleviate that.

I tried the bolts to get my crank apart. Busted my butt and got nowhere. Used a twenty ton press. No problem.
I heard you can do about the same to get them together. Get some 1/2 thick steel. Drill matching holes in the steel just a bit farther apart than the flywheels are in diameter. A couple long bolts through the holes. Slide the steel between the flywheels by the rods, Center over the center pin, tighten the bolts.
I don't reccomend either the bolt trick or the clamp trick. I have built a couple cranks with a 20t press. I would reccomend that and welding the crank. When I rebuild the crank for the 750 rephase, thats how it will be done.
I'll probably let Hugh at Hugh's Handbuilt do the crank and cam. For it.
Leo

if I had a press I would go that route for sure. I plan to have the crank pins welded to the flywheels, but should I weld any other parts? Should I weld the two halves together too? I hear 6 tons is enough to press these things together well...

Hughs Handbuilt's rephase service is good, but its a bit expensive. i got my camshaft from Mr. Riggs on eBay. It was $185 shipped and I still got to keep my old cam, and the design is good...

And I think it should end up being cheaper to get my cranks pressed and trued than to send them over to Hughs...
 
Bikes looking good! Nice video too. Funny how many bmx dudes have evolved into motorcycles. Everyone I used to ride bmx with pretty much ride motorcycles now.
 
Thanks for the kind words folks :thumbsup:

If you get that crank 100% apart, and aren't to sure about truing it up and getting it right, I'll be glad to help out via messages or services... But, PLEASE make sure you weld up those pins and center section... Too may folks are sending me rephased cranks that weren't welded up and have had the cranks start to fail on them.... No one likes to tear the engine down 2X...

http://hughshandbuilt.blogspot.com/2011/03/failed-cranks-why-to-properly-build-and.html

Not trying to solicit services, just wanting you to make the proper decisions to keep that engine alive :thumbsup:

PS - My favorite ride from 1994 and my current ride hanging out together .

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Old BMXer' don't die, they find gasoline much more efficient - haha
 
just ordered a PMA bracket from ya, Hugh ! :thumbsup:

took the crank today (and the cylinders for boring/honing) to my machine shop to press em back together and true. They will also TIG the pins. But it sounds like I should TIG the two halves together too? I suppose right there near the crank sprocket?
 
Kent,

Yeah, you'll want to weld the center pins of the 2 middle flywheels as well. To do it properly requires complete disassembly of the crank and rods.... Your PMA kit will ship today - thanks for your order...
 
i'm gonna go ahead and say this: I wish I had gone with Hugh's rephase service.

Ended up getting my cranks back today. To press them, true them (and I'm not sure how exacting they were trued), and a little welding on the flywheels cost me $300 here in Mountain View, CA. I coulda sent it to Hugh (and knew that the job was getting done correctly) for the same price...live and learn.

so here she is. new rephased crank, and the cylinders honed, bored, and blasted.
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i do have a question. If I am going to be using 1st oversize pistons, should I be concerned with balancing? the weight of the piston should be greater, so would balancing be in order?
 
I had the engine apart on mine and almost dove in as you are thinking. Thought I could re-phase on my own...did all the research and figured I'd end up spending more on my own and possibly majorly SCREW it up. Wish Hugh would have been around at that time...my next project will have some Hugh stuff. Guaranteed.

Following your build though. Hope it works out!!
 
so did ya ever get it done yourself?


I'm not thinking I made a mistake, but I just hope that the shop trued all the critical points of the crank. I also didnt get to weld the two halves together, so I am just gonna have to make sure to keep the RPMs down to avoid that.


In what RPM range can I expect crank separation?
 
Stay under 4K Rpm and you should fine:laugh:

Do you know if they at least used any kind of Lock-Tite or bonding agent on the splines when they pressed them together? If not, you'll want to keep close eye on your sump filter and such for Alloy shavings, that is a sure sign the cranks have seperated and are chewing through the cases... An no, it won't make any noise to speak of... Also, when cranks seperate, the stock charging systems are affected, as the rotor will try to push into the alternator housing... Your pics are kinda hard to see, did the weld the inner rod pin surface as well, or just the outside?

Once the splines have been pressed apart and put back together a time or 2, they become MUCH easier to seperate, so if that crank ever had a rebuild on it, you "might" have an issue way down the road.

BUT, you should be in decent shape as long as you aren't too hard on it and take it easy...
 
im gonna call tomorrow and ask if they put loc tite or anything like that, and also ask how many tons they used to press. The crank pins are welded on both sides to the corresponding flywheel.

I will keep an eye out for shavings, but 4RPM, REALLY? I can get this thing up to 6-7RPM momentarily, right?
 
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