Putting a 1988 Suzuki Kan of Tuna back on the road

Discussion in 'Some Assembly Required' started by mrchristian, Feb 17, 2018.

  1. neppi

    neppi Been here awhile

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    Have you sync'd the carbs? Again? Do you have idle mix adjusters visible? If so, how much are they open and are they "in sync"? Did you put an inline fuelfilter there? What does that look like?

    Start with carb clean / -sync / idle mix adj. Is your idle speed in spec? Some of these babes actually like to idle faster than what your ear tells is appropriate...
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  2. mrchristian

    mrchristian Been here awhile

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    I think I understand why people hate these things a bit more than other mid-level performance bikes. They aren't GSXR supersports and they aren't quite Concours style long distance cruisers so they exist somewhere in the nebulous word of Ninja 650's and SV650s except they don't have a unique enough or differentiating engine like an SV. In 1988 they were fine but they kept producing them for a long time so they were pretty outdated later on.

    They are the V6 Mustang of the motorcycle word. Sporty-ish vehicle that's not hardcore enough for the hardcore power snobs, not comfortable enough for the comfort crowd. Volume seller that's easy to hate on.

    The Katana Marque was never exclusively a hardcore superbike-homologated bike - they build a shaft-drive "G" 650cc Katana in the early 80's too and a 250cc Katana model in the 90's for Japan. Never seen one though.
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  3. neppi

    neppi Been here awhile

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    Soooooo... How´s it going?
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  4. mrchristian

    mrchristian Been here awhile

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    Everything running great. Replacing the brake pads and tightening the headset got rid of the brake jitter. Just the neutral light has a mind of it's own. I need to take off the plastics for the hundreth time to trace the wiring but I'm just letting it do it's thing for now.
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  5. poppykle

    poppykle Adventurer

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    Just finished reading from start to finish. Great job, I love seeing these "old" bikes bought back to life. Looks like you kept it pretty close to budget as well.
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  6. mrchristian

    mrchristian Been here awhile

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    Still piling on the miles occasionally. Coming up on 4,000. For some reason the exhaust keeps getting quieter and quieter as I keep riding it which I like. That said, I can hear a lot of the top end noise now which seems fine until the bike warms up and there's a fairly loud sort of metallic noise that increases with RPM. From what I can gather these things have a ton of noise, especially the cam chain. Bike has always had oil, doesn't burn any and the original oil I took out had no glitter so who knows. I'm hoping the oil is just thinning out when it's hot and not pushing the tensioner as much?

    Starts and runs fine so the valves must be fine. *strug*

    At 4,000 I'll do another oil/filter change and stick in another jug of Rotella.

    In other Katana-related news Suzuki is bringing back the marque cribbing the "cooler" early 80's Kat. Was hoping it was going to be a turbo or something whacky but it's basically a GSX1000. Still neat!

    [​IMG]
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  7. Millwright98

    Millwright98 Share the love, leave the dirt in the garden.

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    @mrchristian ... had one of these things back in the day.... tough as nails.... try running 20/50 oil.... I seem to recall that made a big difference in the one I had for noise... Cheers!
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  8. mrchristian

    mrchristian Been here awhile

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    Still putting around - unsurpsingly the fork seals went kaput. The seals were so loose when I took the forks apart that they just fell out basically, 30 years old and whatnot. $12 set and back in business. It's amazing how cheap parts are for these. Removed the PVC spacer in the forks to bring them back to street-cush spring rates.

    Filled in the rusty pits on the stanchions with JB Weld and sanded them with 1200 grit while I had them apart. Filled up forks with some leftover 10W and good to go.

    [​IMG]
    [​IMG]
  9. mrchristian

    mrchristian Been here awhile

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    Still having fun with the Katana. Mostly just riding it.

    Found a local welder and got the kickstand reattached. Much better than my rigged dirt bike stand which wasn't too stable.

    [​IMG]

    The previous owner was also super cool enough to mail me the original owners manual! It's full of 80's-tastic fax-machine pictures.

    [​IMG]

    Suzuki officially (in the manual) claims the GSX600F weighs 430lbs dry which seems...wildly ambitious. There's no way this rideable couch weighs in near an SV650. Super smooth cruiser though, even though the RPM's are way high with the (but still factory it seems) gearing.
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  10. mentolio

    mentolio Been here awhile

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    Well done, man. Glad to see you still having fun with that old thing. Any plans to "go naked?" As I recall, those buggers do have awful pretty engines. Seems a shame to keep it covered up.
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  11. Antti

    Antti Been here awhile

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    Nice project!

    Friend of mine has similar 750, think its from around '90.

    Had it from newish and now like 200 000 kms on the clock and no massive failures. Head work done ones.
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  12. mrchristian

    mrchristian Been here awhile

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    The plastics are a collossal pain to deal with especially on a bike that needs constant tinkering. But I love the 80's looks too much.

    Since this is ADVRider, here's an appropriate picture:

    [​IMG]

    Sadly the seat is rapidly disintegrating so that will need to get recovered. Might have to lose the factory maroon color. There was a ton of recovering kits on eBay last time I looked and now they all vanished. They ran about $25 each for front and rear, now they are gone strangely.

    Also the Kenda tires are barely wearing at all. Hard cruiser compound with "relatively" (compared to a Honda VTX or whatever these usually go on) lightweight bike. I'm used to dual sport bikes that are toast in 5,000 miles.
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  13. r60man

    r60man Long timer

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    Excellent work bring this bike back to life.
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  14. VX Rider

    VX Rider Long timer

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  15. mrchristian

    mrchristian Been here awhile

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    My Walmart powersports battery died after a year and some months. It would spin the motor but it seemed like it wouldn't "catch" when the motor went to fire. I tried charging it but that didn't seem to improve things. Replaced with a Yuasa, ordered on Amazon, the battery acid shipped from a separate shipper and that took two weeks so bike ended up sitting for a while. Sadly...thumbs down to the Johnson Controls Walmart Everstart I guess...I've had solid experiences with their JC Everstart car batteries so I figured it was worth a shot.

    Got new battery in and it fired up. BUT a weird fork shudder is somehow back. Last time I scoured the brakes with a brillo pad and that mostly solved it. It feels different this time, under moderate braking I can see the front axle vibrating/hopping around. Steering head bearings are tight, front end is aligned, fork seals are good, the front wheel bearings should be good. There's always something with this thing. I'll report back if I figure it out.
  16. VX Rider

    VX Rider Long timer

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    eeek!

    pull the wheel check your spacers, wheel bearing and head bearings...
  17. mrchristian

    mrchristian Been here awhile

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    Yeah, I think this is the route. Just pull it apart, reassemble and see if anything changes.

    Also the bike fires up within one rotation if it sits overnight. Leave it for a few days and it needs all sorts of cranking to get it to run.

    It'll fire up after work no problem. Next day, no problem, etc, etc. Acts like a fuel injected bike, easiest starting bike ever. Stick it in the shed Friday...when I go to start it Monday it'll take tons of cranking and all sorts of experimenting with choke placement for it to sputter to life.
  18. VX Rider

    VX Rider Long timer

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    That sounds like your float needle is sticking open and or the fuel bowls are draining.
    Or your petcock vacuum is leaking and not letting fuel flow freely.
    You could drain them to see what quantity of fuel is in the bowls after sitting. I wouldn't do this on my VX800;
    unless the batter is fully charged as it takes a bit to fill that front carb bowl after it has been drained.

    Also consider your starting method...I didn't understand how mine 'should' be started (no owners manual),
    So I was mucking it up simply by touching the throttle even with choke off...
  19. Roofchop

    Roofchop Hands up mother stickers, this is a f**k up!

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    Is the long spacer tube between the bearings? And the correct length (sometimes alloy ones get sqished up and are too short)

    Then bearings over tightened and die early..
  20. mrchristian

    mrchristian Been here awhile

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    Turns out it actually was the headset bearing loosening up. I've checked the snugness of the lock bolt while wrenching on other stuff but it still seems to have let the headset loosen. I made sure the 6mm triple tree bolts were snugged too as before and blue loctited everything this go around. Marked the headset location with a paint marker so I'll know if it starts moving again.

    I don't think my float needles have any issues. There's no leaks, no gas in the oil, no rideability issues. I've undone the carb float bowls a few times and lots of fuel always comes out. Just doesn't want to crank after sitting 48 hours. But i'll try and check if there's gas in them after letting it sit the weekend just to eliminate one more thing. I also have kept my idle speed a touch high (maybe at 1400rpm. I lowered it a bit so it's 'leaner' on startup). The tachometer isn't the most super accurate thing so we'll see if this helps.

    Thanks for all the advice everyone!