'78 GS550 Engine/Clutch rebuild questions

[XL-erate]

Hi guys & gals!

I'm looking seriously at a GS550 based side-hack project. I will modify frame, gusset where necessary, and build sub-frame for the hack. Bike is one I mentioned before, a basket case. But, I have to change so much to do the hack conversion it doesn't matter so much what's missing, probably needs change anyway!

What am I looking a $$$ wise for a very basic engine rebuild?

Bike has some Wiseco stickers on it so may have O/S pistons, not sure. I'm thinking hone correctly and re-ring if bores measure okay. Are oversize rings ever available? I expect to at least lap in the valves. How about timing chain, what's involved there? So that question is rings, valves, gaskets, timing chain, what am I looking at?

I hope the cluch will be fairly simple. Are there other areas that are serious chronic problems known on 550's that should be addressed at rebuild?

How about bigger pistons/cylinders if it comes to that: cheap tricks?

No history on what's left of the bike so it's a shot in the dark, trying to get a decent picture what I may be up against. Thanks for any suggestions!

XL-erate

[Nessism]

Don't mean to damp your enthusism...but sounds like you are getting way ahead of yourself here.

Check out the engine you have before scheming to change pistons, valves, cam chain, ect. The service manual has service limit measurements for things like piston to cylinder clearance, cam chain length, valve to valve guide clearance, ect. that you should check out. If something is out of spec, fix it then.

You can get a free service manual download at repairmanualclub.com

Good source for a gasket kit is sudco.com Good people there.

And some members here have reported success in putting a GS650 top end on their 550's - cylinder, pistons, head, carbs. Don't want to get your head spinning too fast since you said money is tight but...

[XL-erate]

Thanks for the tips and info! I checked repairmanual.com but didn't see anything for a 550 4 cylinder, but will look again.

It's not that I'm getting ahead of myself really: don't want to jump into replacing say the pistons and then find out I could have picked up 100cc's more for near the same price. I don't know anything about Suzuki GS550's except what little I've learned here, so fishing.

I'll check the parts link and maybe get a handle on basic prices of rings/gaskets and go from there.

Do you happen to know if there's any inherent weak points in GS550 engines, mods that should be made for long life or problem areas? Oiling? Cams or cam chains? I have another make 750 available, very complete, but they have several known problems that can get dumb expensive, so considering this Suzuki again. Key word for me: reliable.

Thanks again!

XL-erate

Don't mean to damp your enthusism...but sounds like you are getting way ahead of yourself here.

Check out the engine you have before scheming to change pistons, valves, cam chain, ect. The service manual has service limit measurements for things like piston to cylinder clearance, cam chain length, valve to valve guide clearance, ect. that you should check out. If something is out of spec, fix it then.

You can get a free service manual download at repairmanualclub.com

Good source for a gasket kit is sudco.com Good people there.

And some members here have reported success in putting a GS650 top end on their 550's - cylinder, pistons, head, carbs. Don't want to get your head spinning too fast since you said money is tight but...

[Nessism]

It's repairmanualclub.com Factory repair manual with all the supplements - big download.

There are no inherant weaknesses in the 550 engine. It's bulletproof. Charging system is not the most reliable but that is not an engine problem per say...

In terms of cost effectiveness, sounds like you are going to have more into the bike than it's worth. Very common problem. Make a spreadsheet and add up all the costs before going forward with a complete rebuild project - it typically costs more than just purchasing a complete bike in running order.

[waterman]

Ball park rebuild. Rings $100 (4x$25 a hole), cam chain $20, new guides for chain if needed $100, hone for cylinder $30, gasket kit $90, using existing pistons, cylinders, heads. Maybe another $200 if needing oversized pistons, etc.

Possible upgrade: 650 top end on 550 lowers. 650 pistons, cylinder block, and preferably 650e (chain drive) head, valve covers. Price is whatever you can obtain items, cheapest to buy whole engine, can be acquired by part from ebay. This is not exactly a bolt on upgrade, others have done it. Since it is going on older (pre 80) engine will need 650 cv carbs to match head. May also need 650 exhaust, not sure 550 will fit. Benefits; more displacement for cheap, and 6 speed transmission.

I would agree with others, probably cheapest to buy another 550 engine whole or find another whole parts bike. I picked up a running 82 550 L for less then the simple rebuild price in decent condition.

[XL-erate]

Thanks for the further info. As far as purchasing a running engine I haven't had the best experiences on the net. I just bought 2 different stators for a Honda, both in good shape according to sellers, both junk. No refund on first one. Second one the other guy says to ship it back and he'll refund, so I pay shipping twice. Not only that but once he gets it back he claims it 'tests good' so no refund. Now he has my money and the stator, and will not return stator without a third shipping charge.

I will have to do some major mods to any bike to run the sidecar: frame reinforce, sub-frame, forks, wheels, brakes, lighting, electrical, shocks etc. Not really practical for me to buy a complete bike, which I can't afford anyway. Piece by piece I might be able to afford it, but income is extremely low and unchanging. Thanks for the help and info, guys.

XL-erate

[waterman]

Don't know where you live but here is a fairly cheap looking 650e.

http://cgi.ebay.com/ebaymotors/1981-Suzuki-GS650-GS650E-GS-650-650E-Motorcycle_W0QQcmdZViewItemQQcategoryZ35599QQihZ001QQitemZ110239665566QQrdZ1QQsspagenameZ

Would love to see ideas on sidecar. I have a need or two for one and would love to give a go with one of my bikes. Best of luck.

[Nessism]

8V 550 engine makes about 49 hp (on it's best day). My opinion of course but I don't think it's suitable for pulling a side hack. When you consider the amount of work involved with building the bike, it only makes sense to have a little more grunt.

[XL-erate]

Thanks, guys! I'm on the fence on the 550, looks like I need more research. For my use the 550 would probably give enough scoot to it, as I'm lightweight and also don't plan to build an expedition rig. Just looking at limited touring, traveling light, plus a grocery runner.

The other choice is the GS550 chassis with my Honda 450 engine which is a possibility, but not real keen on that. Finally, I just stumbled across a complete V45 Honda nearly free, but that engine had its own issues.

Reliability: Suzuki.
Moderate power & reliability: Honda 450 engine.
Much more power, good handling: V45, but a few engine mechanical issues. From what I understand they go like stink but have an appetite for cams, at about $1000 per change!

Overall a hard decision. Suzuki has it hands down for long term reliable, excellent handling and probably enough power. If I build a Suzi rig you bet I'll post up pics and info on the build! Thanks, guys! Appreciate the help...

XL-erate