Checking for life in an engine

[Guest]

Hello

I purchased a 1983 GS650 for cheap. The bike is in pieces and needs a lot of work. It has been sitting for a long time with muffler holes wide open and carb holes mostly covered with masking tape. I went through 15 pages of the engine discussion looking for guides and more information.

What would the first steps in checking if the engine is working or what conditioning should I do before I plug in the electrical? I have never done this before so links, documentation, tutorials or walk throughs would be appreciated. Thanks

[tom203]

Well, congratulations! First determine if you have all the required components. Was it in covered storage, sitting in a nice dry basement? You do understand that it was "in pieces " for a reason, right? If you can, show us some pics, so we can bless it!

[Mop Bucket]

I have minimal history on the bike. I bought off a person who bought it in a lot sale. I do know it was last titled in Texas. The last owner did have it in a garage, but before he bought it no idea. Pics:

[tkent02]

Start with posting a location.

[GSX550]

First thing I would do it to pull the plugs and drop some oil down into the cylinders. I would then very slowly try and rotate the engine by hand. If that goes well, I would then check to see if I could get the transmission to shift through all the gears, remembering that you may need to rotate the rear wheel a bit to help things along.

I would then connect a good battery and see if some of the electrics work, including the starter. If she will spin I would connect a compression guage and take some readings of all the cylinders. They will be lower than they should be due to the engine being cold, but higher than otherwise due to you having put oil in the cylinders earlier. If your readings are even and above 100psi you should be alright.

I would then make a tally of what is missing and start asking the good folks on here who has what.

I would not attempt to start the engine until you have dropped the oil and replaced it and the filter. I would use cheap stuff first just to help clean out whatever old gunk is in there. You could also do an inspection of the oil for metal part to see if that indicates other problems.

Of course if the engine wont rotate, before you start to apply He-Man force, pull the valve cover and make sure that the timing chain is connected and appears to be able to move the valves. Drop in some penetrant to the cylinders and let it soak then start to apply successivly more force trying to crack the pistons free.

Have fun and keep us posted!

[kahuzlefitz]

The first thing I would do is pull the engine and rebuild it. I say this becuase I noticed the picture of the open exhaust valve. If that exhaust valve has been open the whole time since its been sitting and it wasnt stored in a climate controlled area more likley than not there is some form of rust on the inside of that cyclinder. PBR blaster would work very well but I'm not sure how you would manually turn over a bike motor. And for all the nay-sayers for this idea;I was able to make a siezed flatty in a 35 chevy bus that had been sitting for 30 yrs in North Carolina turn over manually in about a half hour. Anyways, do yourself a favor and just pull the whole motor apart, clean it up, replace anything that is worn or broken, and finally make sure you run conventional oil for the break in period. If you go straight to synthetic the motor will never break in properly. I hope this was helpful.

[tkent02]

The first thing I would do is pull the engine and rebuild it. I say this becuase I noticed the picture of the open exhaust valve. If that exhaust valve has been open the whole time since its been sitting and it wasnt stored in a climate controlled area more likley than not there is some form of rust on the inside of that cyclinder. PBR blaster would work very well but I'm not sure how you would manually turn over a bike motor. And for all the nay-sayers for this idea;I was able to make a siezed flatty in a 35 chevy bus that had been sitting for 30 yrs in North Carolina turn over manually in about a half hour. Anyways, do yourself a favor and just pull the whole motor apart, clean it up, replace anything that is worn or broken, and finally make sure you run conventional oil for the break in period. If you go straight to synthetic the motor will never break in properly. I hope this was helpful.

Great idea, if you have a ton of money and time to waste.

[Mop Bucket]

First thing I would do it to pull the plugs and drop some oil down into the cylinders. I would then very slowly try and rotate the engine by hand. If that goes well, I would then check to see if I could get the transmission to shift through all the gears, remembering that you may need to rotate the rear wheel a bit to help things along.

Sounds like a good place to start. How much oil into each cylinder? Maybe a dumb question, but how do I rotate the engine by hand? I have a lift if needed. Seems like I have read where people have done compression testing without firing it up, is this possible or any value on checking the state of the bike?

Start with posting a location.

I am in Las Vegas, east side.

The first thing I would do is pull the engine and rebuild it.

I am not opposed to rebuilding, but I am hoping it is not needed?

[tkent02]

I am not opposed to rebuilding, but I am hoping it is not needed?

Why would it be?
If it is free to turn, or can be freed, if it eventually has compression, and if it runs well why would you want to?

[COLOR=black][FONT=Verdana]Sounds like a good place to start. How much oil into each cylinder? Maybe a dumb question, but how do I rotate the engine by hand?

A few tablespoons in each one for starters. Marvel Mystery Oil is good at freeing things up, as is ATF. Leave the plugs out when you try to turn the engine.

Remove the round ignition cover over the right end of the crankshaft. Put a 19mm box end wrench on the end of the crank to turn it clockwise. If it doesn't move easily, wait for the MMO to soak longer. It may take a few hours or it may take a week or more. Do we even know it's stuck yet?

A compression test is meaningless at this point, I wouldn't expect good compression on an engine that has been sitting. Once it has had the valves adjusted properly and has run a thousand miles or so, the compression should come up. It's really not all that important.

[Mop Bucket]

Why would it be?
If it is free to turn, or can be freed, if it eventually has compression, and if it runs well why would you want to?




A few tablespoons in each one for starters. Marvel Mystery Oil is good at freeing things up, as is ATF. Leave the plugs out when you try to turn the engine.

Remove the round ignition cover over the right end of the crankshaft. Put a 19mm box end wrench on the end of the crank to turn it. If it doesn't move easily, wait for the MMO to soak longer. It may take a few hours or it may take a week or more. Do we even know it's stuck yet?

A compression test is meaningless at this point, I wouldn't expect good compression on an engine that has been sitting. Once it has had the valves adjusted properly and has run a thousand miles or so, the compression should come up. It's really not all that important.

Tkent02

This is perfect information for a newbie. I will give your suggestion a try and take pictures.

[GSX550]

Yeah, as I mentioned in antoher post, the general concensus is that an engine will run fine on 90psi. The reason for running a compression test once it is confirmed that the engine turns is to check for problems such as head gasket leaks, burnt valve, hole in the piston, etc. You don't need to start the engine, it just needs to turn over at a normal starting pace for 3 revolutions or so. Make sure to hold the throttle wide open or have the carbs removed.

The reason I am suggesting to put oil down the bores now and try and turn it over by hand is that you don't know what is going on in that engine. There could be no timing chain or a broken timing chain, so if you put a battery in and hit the starter you would bend some valves....There are a myriad of reasons why just gently turning the engine over first by hand is a good idea. You just never know what the PO did.

As tkent said and I aluded to, don't pay too much too much attention to the numbers of a compression test. If one cylinder reads 0-10psi and the rest 70-90, then you may have a problem, if they are all 60ish or so, then chances are with a little running and some basic maintenance the engine will come good.

[tom203]

Looks ok, odometer reading? Lower engine cases and stator cover are really clean. Pull plugs, put bike on centerstand (looks like it's there), stick it in some gear and rotate back wheel. Use straw or tube to scoop out some crankcase oil- what does it look like? Don't worry about any compression tests yet!

[Mop Bucket]

A little more information and maybe some clues as to what the PO was doing. Looks like the frame was repainted or maybe powdere coated, including the drive shaft. When they put the drive shaft back on they left off the boots. The oil in the glass window looks clear and the odometer had 30,000 on it.

I also was looking at the plugs and it has 3 never fired new plugs and one that looks old and stuck. I will put pentrating oil on it and try to take it out later.

Anyway, I am hoping everything was working before they tore it down and painted.

[tkent02]

If one cylinder reads 0-10psi and the rest 70-90, then you may have a problem, if they are all 60ish or so, then chances are with a little running and some basic maintenance the engine will come good.

Even so, the one with 10 psi could just have the valves adjusted too tight, could have rings stuck in the ring grooves, could have a valve stuck slightly open, any of these can fix themselves with some time spent running down the road.

Or there may be a problem, but most of the old GSes that I have resurrected have worked fine after getting them adjusted and running. This includes some that were seized, and a few that had very poor compression at first.
The only one I couldn't get any compression out of was a rebuilt 750 that was "broken in" with the throttle closed the whole time. This guy just putted around for the first thousand miles or so. No good, the rings never seated at all.

[tom203]

Maybe they seperated drive shaft at U-joint to take motor out of frame for painting- but it's a BIG no-no to not reinstall boot. Also what's with that blob of metal adjacent to cam cover bolt near spark plug #2 ? ( sitting on bike ,plugs are numbered 1 to 4 starting on left).
One spark plug stuck? Oh, no!
Are the carbs as oxidized as they look, or are my eyes blurry?