Starting an old motor for the first time

[DCrippa]

If it turns and has decent compression / has been oiled and filled with fresh everything is it foolish to try to fire it up w/o splitting the head first for a more through inspection of the internals?

Could valves be stuck and is there an easy way to determine this? What are other pitfalls to look out for?

On my 550 - looking through the exhaust port it looks like some of the valves are in an open position / exhaust stroke, cranking the kick w/o power being applied should show valve movement correct? Though it does turn over, I haven't visually tested this yet (to see if the valves go up and down) as I'll need a friend to help me do it.

Once all buttoned up I really want to fire it up to hear how it runs - but I am not sure if that is a risky thing to do w/o checking all the internals first. If I get it running I do have intentions of then tearing it apart / powder coating frame, cleaning the motor etc... just want to make sure I have a running motor before moving forward with any of those expenses...

The PO said it had been parked from a running condition - However when I found it, it was parked outside. The valves are pretty black viewed from the exhaust port and the exhaust gaskets are one with the port.

I worry that in firing it up I could screw it up worse if there was a stuck valve or other corrosion that could cause problems for the piston or rings... Any advice would be appreciated.

Please excuse me if there are posts on this specific matter. I tried searching and have read various threads on valves and putting a bike back together but I didn't find anything specifically to starting an old motor other than running through the various checklists one would do in rebuilding. Bass Cliff's site is invaluable and at the risk of riling up some feathers maybe a thread with this title and discussion could help others... or not.

[Ghostgs1]

Do you have a kick start? If so try turning it over with ignition off. If no kick starter, you can turn it over with a 19mm wrench on the ignition end of the crank. If she turns smoothly then try starting it after changing engine oil and filter. Might want to check valve clearances first. Good luck, Ray

[Nessism]

Do all the maintenance (carb/tank clean, airbox sealing, valve adjustment, ect) and fire it up. You won't hurt anything that isn't already messed up.

[chuck hahn]

removing the plugs will also make it easier to roll over afew times with the wrench on the crank..just sayin

[7981GS]

I am not one of those with the "just run it" mentality.
If it has been sitting for any extended length of time outdoors, especially with the exhaust detached, you might want to disassemble it first and inspect it.
These are picks from a "running" engine:





Just running it, would have been catastrophic. It clearly NEEDS at least a 2mm over-bore.


Daniel

[Nessism]

I am not one of those with the "just run it" mentality.


Just running it, would have been catastrophic. It clearly NEEDS at least a 2mm over-bore.


Daniel

I doubt anything catastrophic would have happened. It just would have run poorly and maybe burned some oil.

I've brought eight different GS's out of long term storage, and the only ones seriously F'ed up inside the engine were two that where heavily modified. Of course, if the bike sat outside without the exhaust that could be a problem so further investigation is warranted in cases like this.

[DCrippa]

You're right, It was outside - exhaust stuffed with rags - this probably falls into the category of anything worth doing is worth doing well... I'll save up for some gaskets or gasket material (as I saw files for making your own, very cool). It's just that being on the cheap I was hoping not to have to but it didn't look so promising from what I saw as gut feeling - I'll try to snap some pics.

[Hoosier Daddy]

You stated it has decent compression.. is this a known fact? what kind of numbers? If so, your valves are in good shape and moving as they should.
A fellow goldwing enthusiest Randakk has a nice write up on his website for Starting an engine after a long lay over. It's basics apply to almost any engine, just ignore the "Coolant" related line

http://randakks.com/TechTip24.htm

[DCrippa]

Nope not an official compression test and was only on one cylinder - will need to bug my neighbor for that since he has the tool... just the finger over the plug hole and turned it over with the kick with a friend.

Thanks for the link.

[Nessism]

You can not judge compression on an engine coming out of long term storage since the rings can stick a little but will free up after a few hundred miles or so, plus you can't judge compression on a cold engine anyway.

If you want to pull the head fine. You should also plan on pulling the cylinder then too since the base gasket and rubber seals should be changed anytime the head is pulled. While the head is off you then should change the valve stem seals and maybe even the rings if you want to be 100% sure everything is the best it can be.

My personal experience has taught me that pulling the head just because the bike was sat is not necessary in most cases, again, unless some monkey has been inside the engine, it has been seriously neglected, or has a lot of miles.

[DCrippa]

I can hear the cash register ringing already lol... Making a list - figure I should have those things on hand anyway.

Well, a lot of unknowns with this one - I believe the motor is in stock condition the PO didn't say anything about engine mods. Most of the new used parts are from different bikes. So I have no idea on the mileage or it's history so all bets are off. I know I need to eventually check the valve clearance and do the shimming thing... that'll come in time.

I may try to fire it up per the recommended directions in the link provided if everything checks out more or less and my neighbor gives it a thumbs up. Luckily he's a professional mechanic and an ex racer that I've learned a lot from. The carb bank I bought probably has stock jets - so I'll need to up those as well given the pods and exhaust... funny how it starts out cheap and really starts to rack up... I'm up to $500 right now including purchase of the rolling chassis and can easily see another $500 or more considering I'll want a new chain and rubber eventually if this thing works.

I was watching Cafe Racer last night and this one dude was talking about dresda valves - and how they're lighter bla bla bla... if I do tear into her I wouldn't mind looking into replacing the valves with better ones - do they make these for the gs550?

Also I think another member here sold to the PO another member - supergrafx, I forget who though. I should ask as it may help piece together it's history...