GT550 Rebuild and Restomod

[kadavenport]

All part of the fun right? At least I know she will run. That was step one. Now tuning.

[yeadon_m]

Kyle,
+1 on what you and Alan said. They only do it to amuse and frustrate you. You do know that these restorations are never completely finished? and amen to that, what a dull life it would be if there was nothing to tinker with?
On the carbs, I have a habit of lightly tapping the float bowls with a screwdriver as I prime whenever they've been off the bike. I have found a few times that when I didn't do this, fuel would pour out of an overflow. I've taken to popping the tank on and priming the carbs as soon as they're on, immediately after fitting them. If they're gonna leak, I want to know BEFORE I've fitted everything else!!
Cheers,
Mike

[kadavenport]

Tried tapping, but it was still leaking albeit less than before. Might as well thoroughly clean them now, just to know they are right. No sense getting frustrated trying to tune dirty carbs.

[kadavenport]

So, decided to take a break from the mechanicals for a day and worked on the seat. I also wasn't happy with the boxier sear design, so I did a rounded version (uses less material too) and liked it better. After the wife and kids went to bed, I cut out pieces and got them bent up. I'm really pleased with the fit. Next, it will be OA welding them up, trimming and polishing.

New GT550 Seat Design


Templates


Posterboard Mockup


Po' Man's Slip Roll


Fitment




If all goes well with the seat, it will get shortened so a tank similar to the one on the T500 below will get used.

[kadavenport]

Carb cleaning and minor points adjustment worked:
https://youtu.be/5or8lznSgPs

Now I'm trying to track down where all the burnt oil and gas is coming from. There is a lot after it runs for a while. Under the middle of the bike, drips from the exhaust, but I can't tell where it is originating. It does not appear to be coming out of the cylinders at the exhaust...

[yeadon_m]

Kyle,
The bike sounds rock steady. The gunge underneath is most likely to be melted greasy mess accumulated in the centre pipes where they join the downpipe. Sometimes, long-disused pipes take ages before they stop being oily messes once the bike is recommissioned, as they have not been properly hot for long enough to dry them out!
Good luck,
Mike

[kadavenport]

Kyle,
The bike sounds rock steady. The gunge underneath is most likely to be melted greasy mess accumulated in the centre pipes where they join the downpipe. Sometimes, long-disused pipes take ages before they stop being oily messes once the bike is recommissioned, as they have not been properly hot for long enough to dry them out!
Good luck,
Mike

Thanks for letting me know, that makes perfect sense. Maybe I'll use the mess as an excuse to get, or take a swing at fabbing up chambers. Speaking of, there is a set of badly used GT750 chambers (3 into 3) on ebay for $150. Not sure if they are salvageable, but thought someone might want to take a chance. There are also badly used GT550 chambers as well, but the guy is still asking $400.

[tz375]

I couldn't find the 750 pipes on ebay but the 550 appear to be Bassani and are good pipes. That's a bit pricey for old pipes though. baffles in those things are not too complicated or to remanufacture, but still a PIA to have to do.

[oldjapanesebikes]

Now I'm trying to track down where all the burnt oil and gas is coming from. There is a lot after it runs for a while. Under the middle of the bike, drips from the exhaust, but I can't tell where it is originating.

One thing that can help with the leaking joints is that the pipes need to be able to 'float' a bit. If they are bolted up hard to rear hangers then they tend to leak more. Not sure if that is case with your set-up, but on the GT750 there is a bush - I think on the GT550 they used a spacer also ? Take a close look at a parts manual to be sure you have the right bits.

[kadavenport]

Now I'm trying to track down where all the burnt oil and gas is coming from. There is a lot after it runs for a while. Under the middle of the bike, drips from the exhaust, but I can't tell where it is originating.

One thing that can help with the leaking joints is that the pipes need to be able to 'float' a bit. If they are bolted up hard to rear hangers then they tend to leak more. Not sure if that is case with your set-up, but on the GT750 there is a bush - I think on the GT550 they used a spacer also ? Take a close look at a parts manual to be sure you have the right bits.

Hey Ian - thanks for the follow up. I do have the exhaust gaskets if that is what you were referring to. If I remember right the torque spec on the exhaust was really low, like 10lbs if I remember right.

[kadavenport]

Bit the bullet, put up the scrap metal and took a swing at getting the seat welded up. I was able to get it tacked up. I've got a bit of distortion, but over all I'm pleased with the small amount of welding I had time to do.

Pic of cleaning the flux off with boiling water.

[kadavenport]

Seat Progress





Slow going of setting up torch, lighting, welding, turning off torch, grinding, brushing, cleaning, flux, setup torch, lighting, welding...
over and over. Still have 1 pin hole and 1 crack, and lots of filing and sanding to do.

[dgoodsy]

Good progress! what type of welding? oxy acetaline? What type of metal are you welding?

[kadavenport]

Good progress! what type of welding? oxy acetaline? What type of metal are you welding?

5052 Alloy, OA welding using an old victor torch, and number 2 tip and 40XX welding rod.

[dgoodsy]

Did you do all your own bending, rolling and cutting?