Beefing up the 650

[deeje]

Looking to give the ol girl a bit of an overhaul. --> 83 GS650 Katana (shaft drive). I will not pretend to be the mechanical genius here, simply because I am not one. This is where you guys come in.....[-o<

In a bike of nearly 25 years of age, what parts will need to be replaced? I hope that what ever work I do, will last me say another 10yrs at least. The bike is running reasonably well. Slow to start up at times but once she is warm, nothing can stop her. This is more of a proactive maintenance job for me.

This might be a good time to replace what ever parts I do, with newer or compatible performace enhancing parts... if there are any out there?

Parts within the motor (i have a limited knowlege about the mechanics of a motor) which can be upgraded?

I have read a few threads about pod filters (i like the look of them) and jet kits for the carbs. The bike already has a 4-2-1 exhaust, old and a bit ratty, probably needs replacing.

Are there any 4-2-1 exhausts that come in black as standard? I have seen a few crome or s/steel looking jobs out there but i definately like the black ones.

dyna ignition? any ideas about this? I have seen a few threads on it but nothing I could see for the 650

Like I was saying... not after 'out of this world performance', just a little boost and a reliable ride is all i am after.

If people could list parts and if possible, where to get them from (anywhere in the world) would be greatly apreciated

[txironhead]

I have limited experience in motorcycle engines, but I've overhauled a lot of other engines from lawnmowers to a 512 dragster, so I'll pitch in my $0.02.

I looked at the Dyna website and didn't find an ignition, either S or 2000, listed for your bike, so I'd email or call them and ask them for their recommendation. I'd at least upgrade to Dyna coils.

As far as engine rebuilds, you need to decide whether or not you're going to do a complete teardown or just a topend rebuild. If the bike has been well maintained, you can probably just do a topend. Minimal, you're looking at a gasket kit, rings, valve seals, and machine work. If your cylinders are still in spec, you can reuse your pistons and get stock size rings. If they aren't or you want to up the power a bit, you'll need a competent machine shop to bore your cylinders and new oversize pistons and rings. You may want to check on availability before making this decision.

The head will need to be thoroughly checked, valve guide clearance, etc. There is a debate between a three-angle valve job and a "rounded" valve job, apparently the rounded job is the latest greatest craze. I've never had a problem with a three-angle but you may want to look into the different options. Replacing the valve seals is a must, and you want the valve guides and seats checked, and the springs need to be tested or replaced. Have the cams checked, if they're worn they'll need to be welded and reground or replaced. Porting and polishing the head might be a good idea, but only if the machinist understands motorcycle engines.

If you can't find a 4-2-1 that comes in black, see if you can find a company that will Ceramikote it in black. I personally like the black header/chrome muffler look but that's me. POR-15 makes a "Black Velvet" kit that's supposed to be fantastic stuff, but the original coating needs to be removed or prepped prior to application, and apparently doing the exhaust yourself can be tricky so you may want to find a shop that will do it with a warranty.

Keep in mind that all of these mods, regardless of the options you choose, will change your carburetion somehow. You may need to even look into running larger/different types of carbs. And there's always fuel injection....

This is just a rough outline, but hopefully it'll give you a few ideas and a ballpark of what you'll need. The main thing I recommend is finding a good machine shop that knows motorcycle engines. They will be your best friend.

Edit: Almost forgot: You'll probably want to replace your intake boots, or at least the o-rings, and ALL of the hoses.

[ap72]

I'm planning to overhaul my 650 within the next couple of months and will shave the cyluinders some to increase compression, bore it out a little, and get cams ground from Web Cams (they need cores though). Along with the recomended ignition possibilities, pod filters, and a good carb retune you should be in great shape.

Also at this time for durability's sake I would install an oil cooler- no sense in overheating a fresh engine...

[Thad Q.]

With a little massaging you can fit a Dyna S on your GS650G. I just did it last weekend. I still have yet to ride te bike but it started right up. Timing was kind of a pain but so far it seems ok...
Thad Q.

[brveagle]

I'm planning to overhaul my 650 within the next couple of months and will shave the cyluinders some to increase compression, bore it out a little, and get cams ground from Web Cams (they need cores though). Along with the recomended ignition possibilities, pod filters, and a good carb retune you should be in great shape.

Also at this time for durability's sake I would install an oil cooler- no sense in overheating a fresh engine...

I would love to see this happen....But you better do your homework first. Shaving the head and boring with cams is gonna be one hot motor. I should know. I've pretty much done it.

I have a set of cores if you want them.. for a nominal fee..

[ap72]

I know it'll be a little hotter, but I don't plan to go too radical with the cams and I figure an oild cooler will help compensate for some added compression and thinner cylinder liners. I'm planning to fabricate my own cooler- I just wonder how bid is too big?

I am interested in those cores, the only question is- how much?

[brveagle]

I know it'll be a little hotter, but I don't plan to go too radical with the cams and I figure an oild cooler will help compensate for some added compression and thinner cylinder liners. I'm planning to fabricate my own cooler- I just wonder how bid is too big?

I am interested in those cores, the only question is- how much?

make me an offer i can't refuse...

How much do you plan on boring it out by? What pistons are you gonna run? Oversized rings?

[ap72]

I'm planning on just running oversized stock replacement pistons- overbore will depend on how bad the cylinders are when I crack it open- I'm guessing around .030" or the metric equivalent (I build mostly American V8 motors). The cams I'm looking at are just one step up from stock from Web Cam- I drive a lot on the Interstate so I really want most of my power around 6,000 rpm. I know its not a lot but I'd give ya $20 plus shipping. If you decide its not worth your trouble I understand but its competitive with junkyard prices and ebay buys.