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GT550 Rebuild and Restomod

Posted: Wed Dec 07, 2016 7:29 am
by kadavenport
Hey guys,
First of all I wanted to thank many of you who helped me get this GT550 on the road 7 years ago. She has been a ton of fun and fairly reliable in stock form. Fast forward to last winter, I parked the bike because she died while I was riding and sounded like bb's in a can when I tried to crank her back up. I checked compression, and two of the three cylinders were way below spec. Also, there was crank play and an oil leak. After speaking with Bill Bune I knew a crank rebuild was probably needed, but I haven't been willing to spend more on a crank rebuild than I did on the complete bike. I thought about parting her, but couldn't bring myself to do it. Long story short, I've spent the last year saving dough, and sourcing parts including a crank that appears to be in good condition, cylinders, pistons, and rings.

Also, I'll be doing a bit of a restomod. I've already added clip ons, and been fabbing up rearsets. I've been learning to oxy-weld aluminum, so I'll be making an alloy seat. My goal is to not cut her up, utilizing or preserving all the original mounts, so she can go back to original some day (the bike is in really good shape).

Pictures:
My shop gopher ("Gopher that wrench, Gopher that socket") sitting on "her" motorcycle.
Image
Image
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The seat was my test run oxy-welding aluminum. I had several welds burn through, and decided to widen the seat to sit down over the frame rails and utilize the stock mounts and lock.

Thanks in advance for answering a ton of questions I'll have when I dive into the engine.

Re: GT550 Rebuild and Restomod

Posted: Wed Dec 07, 2016 3:35 pm
by joolstacho
What a little cutie!

Re: GT550 Rebuild and Restomod

Posted: Thu Dec 08, 2016 3:00 am
by Alan H
The bike looks good too!
Glad to hear you're going to keep the bike on the road. It'll be a royal pain at times, but worth it.
I'll be starting another 550 resto in a few weeks too.

Re: GT550 Rebuild and Restomod

Posted: Thu Dec 08, 2016 5:55 am
by jabcb
It what will seem barely more than a blink of an eye, your cutie shop gopher will have you working on her GT185 so she can go riding with you.

Re: GT550 Rebuild and Restomod

Posted: Thu Dec 08, 2016 6:41 am
by kadavenport
Don't worry there is a cb350 waiting for her. :)

Re: GT550 Rebuild and Restomod

Posted: Mon Dec 12, 2016 9:56 pm
by kadavenport
Unpacked and measured the jugs. Pleased to see they were as advertised at 61mm. I was struggling sourcing standard sized rings, so I went ahead and purchased the piston kit from Cruzin Image. It should be here in a week or two.

Re: GT550 Rebuild and Restomod

Posted: Tue Dec 20, 2016 4:29 pm
by kadavenport
The cruzin image piston kit arrived, and I'm fairly happy with the quality. A few noticeable casting imperfections, but nothing dramatic. Started cleaning up my jugs.

Before:
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During:
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After:
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Re: GT550 Rebuild and Restomod

Posted: Tue Dec 20, 2016 6:11 pm
by markj
Nice, what did you soak them in?

Re: GT550 Rebuild and Restomod

Posted: Tue Dec 20, 2016 6:33 pm
by kadavenport
50/50 mix of vinegar and boiling water with lemon juice. Let them soak about an hour and then slowly added baking soda until the vinegar was neutralized. When the water was cool enough, used brushes to scrub them. Rinsed and then ran them through the dishwasher. Dried and wiped down with wd40.

Re: GT550 Rebuild and Restomod

Posted: Tue Dec 20, 2016 8:07 pm
by markj
Looks great. I've used boiling vinegar with carbs and it does work well. Didn't know about adding baking soda....is that to reduce the acidity and corrosion after the part has essentially been cleaned?

Re: GT550 Rebuild and Restomod

Posted: Tue Dec 20, 2016 10:17 pm
by kadavenport
That's what I read on an engine building forum, specifically when talking about alloy blocks. Seemed logical too me, so thought I'd give it a try.

Re: GT550 Rebuild and Restomod

Posted: Wed Dec 21, 2016 7:22 am
by dgoodsy
Impressive work! I have to ask, did you run them through your household dishwasher, or do you have an old junk one in a shop or something? I always wonder this when I hear/read guys say they put their car/bike parts in the dishwasher. I have wanted to try a few parts, but I already know what the wife would say!

Re: GT550 Rebuild and Restomod

Posted: Wed Dec 21, 2016 8:39 am
by Warehouse1001
Just don't use dishwasher soap on any aluminum alloy part. Disaster! Don't ask how I know. :roll: Chuck

Re: GT550 Rebuild and Restomod

Posted: Wed Dec 21, 2016 8:49 am
by kadavenport
I did use the household dishwasher, but that the parts were basically clean at that point, just using it for a high temp rinse cycle. I have a deal with my wife, if I tear it up she gets the stainless dishwasher she's been wanting. :)

Re: GT550 Rebuild and Restomod

Posted: Wed Dec 21, 2016 8:54 am
by dgoodsy
Aah that's a good compromise then! Carry on with the good work.