1971 xs650 build. Newbie will need help

[azcafe]

Hey All

I just purchased an XS 650 1971. It is basically a roller right now. I was going to start by rebuilding the motor. I think all the top end is there but I will have to buy parts for the bottom end. Am I able to buy parts from other years and use them in my bottom end of my 1971.

I will post pics soon and continue to post on this as I rebuild it.

Thanks

 

[GreasyC]

You pretty much have to use all early (256) or later (447) parts. They don't really mix. The connecting rods got shorter in the later motors so your 256 pistons won't work with the later 447 crank because the wrist pin hole is too high. The cam drive sprocket also changed so the later crank also needs the later cam, cam chain, and chain tensioner etc.

 

[jamaral]

Ive got an entire bottom end. No engine covers off a 1971. Let me know if you need anything. Joe

 

[azcafe]

Thanks for the response everyone. Jamaral I will most likely be needing parts but I need to tear down the motor and take an inventory of what I have.

Thanks,

 

[azcafe]

Hey All,

So I started to tear down the motor last night. I got the top end off but couldn't separate the bottom case Ill probably wait until I have some extra help to get that done. Here are some pics.

here is a shot of the piston. Looks to me like its in good condition but this is my first rebuild so feedback is welcome.

Here is a pic of what I believe is a magneto type deal. I know a lot of people are using a PMA as a replacement. What do you think would be the best option if I am going to run minimal electrical and would prefer not to have a battery.

Here are the rocker arms. I did not see how to remove those are do they not remove? Also what do you suggest for cleaning the rust off?

this is the bottom case with the side cover and clutch basket removed. This engine pretty much had no internals on the bottom end when I bought it.

other side of the bottom case.

Here is a pick of the valves. Again what is best for cleaning the rust off?

Here is a look at the valve springs.

this is how i purchased it.

close up of the carbs.

I want to go through a clean everything and then take an inventory of all the parts I need to get. Then I will start to do the rebuild. The one thing on this bike I have the most trouble understanding is electrical. I am not very informed on electrical systems and how they work. Does anyone know a good thread on here that will help me get a better understanding.

Thanks,

 

[gabecustom]

check out the xs650 Tech link.. lots and lots of info and Q&A. as fare as the rust is concerned, soda blast every thing! soda blasting is way easier on the engine parts. the valve springs and valve guilds/seals will need replacing.. and probably the valves to.. kind of a replace one, you need to replace all sort of thing.
correction welcome.

 

[650Skull]

The Tech menu is your friend.

A couple of links that covers most all of what you need to know.

http://www.xs650.com/forum/showthread.php?t=9625

http://www.xs650.com/forum/showthread.php?t=10561

 

[jamaral]

the bottom end of motors i believe are specific to the 1970-1971 models. I believe they had the longer rods. Can anyone else enlighten on this?
what's the no on the bottom cases? do you have a cross over tube or ports under the carb mounts. Lets make sure you do have a 71.
I'm saying this because I have a complete 1971 bottom end here for sale. Or if you need parts from the bottom let me know. Joe

 

[azcafe]

Jamaral

It is my understanding that the 70-73 were pretty much the same running the 256 motors but in 72 they added an electric start vs kick start only. In 74 they started using the 447 motor which will have different internals. I am going to take an inventory of all my parts this weekend and find out what I need. I will PM if I need anything I appreciate the help.

Thanks,

James

 

[gggGary]

It's your bike, but my advice is to look for a better motor to start from. That is very rough and I cannot imagine you getting a decent runner out of it without spending horrendous sums of money.

 

[mick71b]

It's your bike, but my advice is to look for a better motor to start from. That is very rough and I cannot imagine you getting a decent runner out of it without spending horrendous sums of money.

And no electric start, either.

 

[azcafe]

Hey All,

So I got most of the main parts I need for my motor. I got all the bottom end pretty much and another top end that is in much better shape than my previous one. Also I purchased new gaskets, valve seals, cam chain, valve seating tool from mikes. I also got a cam chain tensioner but I believe it is for a later model engine either a 78,79, or 80 engine. Will that work on my 256 motor. I know mine has the 6 hole pattern. If it wont work where is a good place to find a cam chain tensioner at. I will post pics of everything soon.


Also any tips on commonly overlooked steps when reassembling a motor.

Thanks

 

[azcafe]

Hey All,

So its been a while since I have posted on this build but I have mainly been reading and collecting parts for the build.

I got a bottom end from CleonCleon who is local and he has been helping me out a lot on the build. Once I got the bottom end in place I sealed it up with some 3m bond and torqued down the bolts.

Then I worked on getting kick start and clutch basket in place. I have the clutch basket all in place I just need to torque down the center nut and I need to make a tool to hold the unit in place. Ill probably do that tonight or sometime this weekend.

I was having troubles finding all the parts for a cam chain tensioner for the early 71 model. I was able to find the tensioner itself but not the plunger. I decided to just switch to the new style tensioner since I have a plunger off a later year. I ended up cutting the pin that the cam chain is wrapped around since I didn't want to split my cam chain.

Once I got all that done I was all excited to put together the top end. I started to inspect the pistons and took the rings off of one of them and sure enough the middle ring snapped in half. So I found a set of OEM piston rings standard size on ebay for $20.00 since I dont think you can run the honda or acura rings on the 256. Currently waiting on those rings and then I will start to assemble the top end. I have already replaced the valve seals and lapped the valves to the head. Oh and yes I ended up buying a new head unit with rocker arms that actually moved. The valves and cylinder head was caked in carbon but I was able to clean off most of it.

That has been the story of the motor.

For the frame I havent been doing much to it yet. I took off both wheels and took the forks apart to lower them. When I took them apart I noticed lots of parts were missing. These forks are from a 72 btw. They were missing he spring compressors which I wasn't to worried about since I was going to lower them any ways and could just ditch those. The damper rods were rather interesting the top part of the damper rod which usually has a little rod that runs across it has a cotter pin style rod running through it. Didn't look that great but probably would work just fine. One of the damper rods and a space below the top head and the other didn't and then the piston space thing at the bottom of the upper tube was not there. Then I noticed the c clamps at the bottom of the upper tube were basically home made and looked pretty ghetto. Anywho I figured I would be able to find most these parts online. I send my Dampers to Hugh to put on some lowering kits and good ole usps lost my package . So then I found a killer deal on a set of forks on ebay and pulled the trigger on those. I got those in and they were in great shape minus a little pitting on the upper tube. These ones had all the internals and I sent the damper rods from this once to Hugh to get the lowering kit put on. The day after I sent those out my old damper rods usps lost show up in the mail. I guess thats how the cookie crumbles.

I also got a gas tank that I am debating on using. It was rusted inside so currently I have it sitting in a molasses derusting mix. I bought redkote and need to line the inside. I was going to replace the current petcock on the gas tank with two new ones. Is it best to take out the old petcock weld up the hole and then line the tank? Or is it better to line the tank and then weld up the old petcock hole? Suggestions are much appreciated. I am also debating on whether not I am going to use the tank at all. It is a rather small tank and I am not sure I like the look. I kinda want to wait and see what it looks like when I get the clip on handle bars and a cafe seat on there. Plus its only a 1.75 gallon tank so I wont get far with it. Would have to figure out a way to make a couple gas canister mounts to carry extra fuel

I also picked up a pair of Rebel 250 shocks to drop the back. I haven't mounted them yet but hopefully soon.

Other then that I have just been getting more parts I know I will need. I picked up a Hugh PMA, Pamco Ignition, and a bunch of other parts for future builds.

Parts I know I still need are 34mm clip ons, tires, headlight, sparx capacitor and some other odds and ends.


James

 

[azcafe]

So I finally sealed up the bottom end of the motor installed the kickstart and the clutch and started to assemble the top end. I did it without breaking the chain and it took me a couple of times to get the tdc lined up correctly but sure enough I got it done.

So I was super happy to get this all put together and ready to torque everything down when I realized the piston were put in backwards. Yes I am an idiot, but I guess these are the sort of things you run into your first time building an engine. So I tore the whole thing back down and turned the pistons around but I haven't put it all back together yet. I will most likely do that this weekend.

On a happier note I needed to get a new advance unit because mine had bad springs so I took a trip down to the ole salvage yard and scrummaged through all their boxes of random xs650 parts and wasn't having and luck. So then I headed out the yard to see if they had any left over on a motor and sure enough they did. The guy said I got lucky and he overlooked it when it came in or else it would probably of been gone.

The guys there also sold me a tach plug which I installed the other night.

Hopefully I can have this engine done soon and get the carbs cleaned so that way I can start working on the frame and this build thread can actually get exciting.

Thanks

James

 

[azcafe]

So I have continued working away at the good ole XS. I ordered up a new gas tank since my previous one was just to small only held 1.75 gallons. I ordered and CB160 tank that was in fantastic condition. It was a pretty expensive tank due to their popularity but I think it will be worth it once I get it all done.

As you can see I also picked up a front fairing for the headlight and have got my tires mounted and balanced. The headlight was a 5 3/4" bates style headlight and the fairing is from a Harley Vrod. The tires are a 4.5 x 18 in the back and a 4.0 x 19 in the front firestone champion deluxe. I know they are not good handling tires but I just couldnt pass up the look.

For the stance I have Hughs 2" lowering kit in the front forks and rebel 250 shocks on the back. I really like the way it sits so far. I am going to chop up the frame a bit this weekend by just cutting off tabs I dont need and cleaning it up. I also am going to cut the rear loop shorter and put on a cross bracket or just rework the loop back on.

After I was all gitty about the frame I started to install my PMA from Hugh so I could get the motor put in and I ran into a problem with the install. Turns out my crank case is slightly different then all other xs650 crank cases. What happened was the bracket provided in the kit would not sit flush with the crankcase like its suppose to and when I put on the flywheel it would rub on the stator hardware.

So I emailed Hugh about it and we came up with a plan of action and so I am currently waiting on couple things from him and then we will try to reinstall it and see how it works out. Hugh is such a helpful guy that I know it will eventually get figured out.

I am getting excited now that I can see things coming together a little more. Let me know what you guys think of the build.

 

[I am Carbon]

The tank n faring combo really works for me!
That PMA sure looks sweet too.

 

[azcafe]

Thanks Carbon

I still am debating the seat a rear section. I picked up some poster board so i can play around with it a bit this weekend.

 

[GeorgeKillianLett]

Really nice looking setup you have going!
I am anxious to see what you have in store for the loop are you talking 2 or 3 inches off the loop or more?

 

[jdizon]

Dayummmmm! That looks so Badass! I really dig that tank man.. good choice looks and looks good with the fairing

 

[h3llb3nt1]

Nice job so far. I too like the tank. Seems like you definitely have enough spare engines