1. Dismiss Notice
  2. Hey Facebook people... We've created a group for XS650.com members to connect. Check it out!
    Dismiss Notice

1978 xs650 "build" work in progress

Discussion in 'The Garage' started by bigo, May 4, 2021.

  1. bigo

    bigo XS650 New Member

    Helloo there. I have been eyeballing xs650's for quite some time and the wife finally let me pull the trigger on one and what did I do? yep, I stripped it all down and chopped the back of the frame. HAHA It's a terrible feeling let me tell you. I immediately searched craigslist to reassure myself that I can always purchase a stock bike later. This is my first post so bear with me.

    Gallery Available Here:

    My History:
    I've owned two bikes in my lifetime: a Honda cm400e and an xs1100. I'm not a mechanic but I did stay at a holiday inn express last night. Anywho here's my first attempt at documenting my build as I go.

    The bike
    1978 xs650 Special. I don't have a picture of when I barely got it but here is one after I started going to town on it:

    The bike now:

    Note to self: Create at the very least an outline of your vision/goal and take some notes on how to reach the goals. I didn't come up with a plan of attack so I think I spent money every which way. I did browse/stalk a lot of these forums in the past as well as watched a lot of you tube videos as well.

    At first, I started window shopping online, putting items in my cart and waiting to see if I should just ask the wife for forgiveness but I held back. I realized most of the parts were geared more towards the look of the bike and not really the way it ran. Even though it ran when I bought it, I decided to tear the engine down and focus more on that than the look and feel (for the moment).
    Here's a list of what I decided on and have purchased (most of this stuff way too many already have but lets see what unique stuff I can come up with along the way).

    Complete "Semi" Engine rebuild.
    I don't know anything about machining or what have you so I'm just going to inspect most of the stuff and pray it all still in good condition. I purchased a forney stick/tig welder so I can practice every now and then and then do things like seat bungs and chain tensior etc etc. I'll leave the rest to an experienced pro. THE PROBLEM IS I CANT FIND ANYONE TO HELP WELD THE HARDTAIL HAHAHA mosts welding shops says its needs to be on a straight surface so they say no. I have a buddy so has been welding for a few years not that log maybe ill build a jig? and he can weld it? or I can find a mobile welder somewhere that is willing to help. Sucks oh well.

    To my surprise, everything in the engine looks in decent shape(from what I can tell). It may be in terrible shape and I just wouldn't know.

    Heres a list of what I've purchased. I'm friggin broke now and I have to take it easy from now one LMAO

    Haynes Manual
    Clymer Manual
    The Yamaha xs650 Engine Book

    -=Hughs Handbuilt=-
    motor mounts
    "windowed" neck gussets
    "windowed" top motor mounts
    PMA Kit
    Crank and Cam Rephased to 277 degrees

    So far his products seem/look great, his instructions are great and everything has arrived.

    "Ya Mama" pipes
    277 ignition kit
    FriscoStr tank with peep sight
    Stuff comes in tomorrow exciting!

    I do see them on the line a lot so hopefully they not burned out but I have a few ideas in mind and they do look nice. Hopefully they fit my "vision".

    -=TC BROS=-
    Clutch Friction Plates (I didn't buy the metal plates or springs. Should I have?)
    Weld-On Hardtail Kit
    7/8 Drag Bars
    Athena Gasket Kit

    Engine Oil Seal Kit
    5th Gear OD (heard this helps with vibration? as well as with RPMS?)
    Stock Pistons ( too lazy to clean the stock ones but I thought the bike was due for some new ones)
    Stock Piston Ring Kit
    Cam Chain
    Cam Chain Tensioner Assembly
    Cam Chain Guide (I've read lots of bad reviews but this one looks spot on. We will see. When I took apart the engine, the cam chain guide black slip was detached and I read it has to be bonded together)
    One piece clutch push rod and bushing (heard this is better)
    washers and lock washers

    I did not buy new valves, do I need to buy new valves? if I bought new pistons? I ran outta money HAHA

    I thought about upgrading to a 700cc kit but I decided to keep stock internals with the 277 degree rephase. I'm not racing and I jus want something good and reliable that sounds, works and looks nice and is cheap.

    What are your thoughts regarding vapor/sand blasting and then coating the engine case/cylinders housing parts. Is it worth it? like wont the engine just get dirty after a short while?

    I'll keep editing this post with updates whenever I can.


    Attached Files:

    Greyandridin likes this.
  2. bigo

    bigo XS650 New Member

    Alright so lets call this thread "HOW NOT TO SPEND MONEY?". I think I made a dumb purchase.

    This weekend I was Harbor Freight and ended up buying their sandblasting cabinet. (Not sure if this was the right move). My original thinking while browsing the store, was that I could media blast my all my parts now that they are all taken apart. Of course after making the purchase, I've been reading a lot of posts saying that this could ruin the engine if I'm not careful. Son of a biscuit! While I don't plan on media blasting the interior of the engine, I thought I could blast the exterior so I could put a fresh coat of paint. I didn't want to pay a huge amount to get this done at a shop so I ended up buying the cabinet. The media I purchased was aluminum oxide as that is all they had and it said "Great For Engines"....
    Here is a picture of it assembled:


    I test this on the oil pan?

    and painted it a bit to see how it could look HAHA

    I read that I need to degrease the metal parts before blasting them to avoid clumping up the media so I used "GUNK" heavy duty gel. I may need to get another can but I will use WD-40 as I read it has kerosene and should help.

    Here are the pictures of my engine parts. I scrubbed the head with a brass brush but I plan on media blasting these to remove the carbon deposits completely. Any thoughts??? Should I even media blast the engine exterior? Would the paint seriously look better if it was media blasted?
    thumbnail_IMG_0857.jpg thumbnail_IMG_0868.jpg thumbnail_IMG_0862.jpg thumbnail_IMG_0867.jpg thumbnail_IMG_0874.jpg thumbnail_IMG_0880.jpg thumbnail_IMG_0877.jpg thumbnail_IMG_0870.jpg thumbnail_IMG_0869.jpg

    After degreasing and rinsing with water and hitting them with compressed air, I bagged the parts


    Also all my parts have arrived!!! WOOT WOOT! but I can't do anything with it yet. Got the 5th gear and new pistons and rings. I'm pretty sure I messed up and bought the wrong piston set I got the standard bore size form mikes xs and I hear that I will need to hone the cylinder heads and that might mess with the bore size. We'll see I'll have to measure with the new gauges I bought when the time comes.
    thumbnail_IMG_0882.jpg thumbnail_IMG_0884.jpg

    HOW THE HECK DO I TAKE THIS PART APART???? DOES IT COME OFF. I removed the screw and I've been hitting it with a rubber mallet and it doesn't budge. I want to remove this before blasting to avoid leaving media inside the passage of the case.

    Alright I'll report back when I have more to report LOL! Right now, I'm debating to blast the exterior of the engine so I can paint it and I just sent off the Crank and Cam to get rephased. I should have the PMA system here soon.
  3. 5twins

    5twins XS650 Guru Top Contributor

    Absolutely do not blast any internal areas of your motor. Blasting media can embed itself in the soft alloy and just washing won't remove it. It will come out when you run the engine and it gets hot. It will wreak havoc with and probably ruin all your bearings. Personally, I use glass beads for cleaning the external parts but am sure I completely block off any openings so none of the media can get inside. Here's a cylinder before and after .....



    For de-carbonizing the combustion chambers and removing any old gaskets, you can use paint stripper. It may take several applications but it will safely remove that stuff without doing any damage.

Share This Page