Valve clearance GS550 '78

[2BRacing]

Wow! Those half-moon collars are really rusted onto the pipes!

Make up an effective home-made penetrating oil by mixing equal proportions of acetone and automatic transmission fluid, and spraying the mixture onto the exhaust/cylinder head area every day for a few days.

Good luck!

[11csive]

I'd cut off the pipes but leave several inches sticking out of the port. Then drill through the sides of the pipe and attach a bolt & nut. The idea being to throw a cable or chain around the bolt and then use a slide hammer to pull the pipe out of the head.

Thank you for the answer. Guess I'll have to invest in a new tool to get a damn exhaust off then? :P

I've actually already tried drilling a hole in the pipe, to attach this tool. Not exactly the one on the picture, but one like it. I have no idea about what it is called in English, in Danish it is called a "gulvjern" which translates directly into "floor iron" - a tool made to collect wooden floor. It allows you to put the one end onto something, and then use a hammer on the other end.

https://www.carl-ras.dk/gfx/imager/catalog/37320745.jpg?s=product_node

Wow! Those half-moon collars are really rusted onto the pipes!

Make up an effective home-made penetrating oil by mixing equal proportions of acetone and automatic transmission fluid, and spraying the mixture onto the exhaust/cylinder head area every day for a few days.

Good luck!

Thank you for the recipe. Is that gonna be more effective than any other penetrating rust remover/lubricating spray? If so, I'll definitely give it a try, but I've already had it soaked in a lot of stuff like this for several days I'm getting frustrated with this, so I'll probably try yours anyway

thank you

[JTGS850GL]

Worse come to worst you might use a Dremal cutting wheel or hack saw blade and slice a slit into the pipe. Then collapse it into the middle and pull it out. Just be careful on how deep you cut the pipe. If you cut a little into the side of the head it doesn't matter but try to be careful around the seat.

[11csive]

Worse come to worst you might use a Dremal cutting wheel or hack saw blade and slice a slit into the pipe. Then collapse it into the middle and pull it out. Just be careful on how deep you cut the pipe. If you cut a little into the side of the head it doesn't matter but try to be careful around the seat.

Yeah I thought about that as the absolute last thing to do. I was just concerned about getting all sorts of things into the cylinder by doing so. Wouldn't it be necessary to pull the engine apart and clean it up after doing so?

Thanks a lot for your time and help

[Nessism]

Yeah I thought about that as the absolute last thing to do. I was just concerned about getting all sorts of things into the cylinder by doing so. Wouldn't it be necessary to pull the engine apart and clean it up after doing so?

Thanks a lot for your time and help

Not if you stuffed some tight fitting rags into the exhaust port.

[11csive]

Not if you stuffed some tight fitting rags into the exhaust port.

Well that's what I'm gonna do then. I messed up the exhaust anyway, might as well not use anymore time on this, so that I can get on with all the other things that needs to be fixed. (Still need to check the valve, that's why I was onto the exhaust at the first time. Also got a set of o-rings ready for a carb rebuild. Really looking forward to getting started with this, and all the other things to get the bike running nice and steadily)

[11csive]

Hi guys.

Just a quick update to let you know that I haven't forgotten you, or even worse the bike
I've had a couple of crazy busy weeks, with a lot of work and what not. But today I was back at it, and finally got the exhaust off. (yay, of all the things I imagined I was gonna spend a lot of time with, this wasn't it. But anyway, now it's done)

I had a look at the exhaust ports. As far as I can tell, it doesn't look like there's anything in there preventing the valve from closing. However, the valve in ex. 2 is soaked, unlike the 3 others.

Ex. 2.


Ex. 1 as comparison. (3 and 4 looks like this too)


Sorry for the bad pics, hard to get a good snap in there

Next step is to remove the cams and check under the bucket to see what's going on there, as Nessism suggested.

Thanks for sticking with me, hopefully I'll find a solution to this soon.

[2BRacing]

Just an out-of-the-box thought here, but maybe that number 2 valve cannot close all the way because of excessive carbon build-up around the stem, preventing it from going just that little bit further into the bottom of the valve guide?

I would try scratching the carbon from the valve stem with a piece of hard wood sharpened to look like a chisel point, or something similar. Even careful use of a metal chisel should not damage the valve stem. While your wife is not around, use the vacuum cleaner to suck out the loose bits of carbon.

Just something to try before you go stripping the head.

[11csive]

Just an out-of-the-box thought here, but maybe that number 2 valve cannot close all the way because of excessive carbon build-up around the stem, preventing it from going just that little bit further into the bottom of the valve guide?

I would try scratching the carbon from the valve stem with a piece of hard wood sharpened to look like a chisel point, or something similar. Even careful use of a metal chisel should not damage the valve stem. While your wife is not around, use the vacuum cleaner to suck out the loose bits of carbon.

Just something to try before you go stripping the head.

Definitely worth a try. Any good suggestions as to why there's that much buildup in ex. 2 compared to the other 3?
I'll sharpen a piece of wood to look like a chisel or wedge or something like that, and give it a try.

Thank you.

[TxGSrider]

My work computer doesn't have the greatest resolution, but is it possible that the one exhaust port just looks worse because its wet (maybe from all that stuff you've been spraying to get the pips loose)?

Ive never tried it on a motorcycle, but on the old cars you could clean them valves pretty quick by warming up the motor then running the motor up to a decent speed and spraying a little water in the carburetor. It doesn't take much to clean most of that carbon off the valve and piston tops.

[11csive]

My work computer doesn't have the greatest resolution, but is it possible that the one exhaust port just looks worse because its wet (maybe from all that stuff you've been spraying to get the pips loose)?

Ive never tried it on a motorcycle, but on the old cars you could clean them valves pretty quick by warming up the motor then running the motor up to a decent speed and spraying a little water in the carburetor. It doesn't take much to clean most of that carbon off the valve and piston tops.

I'm close to 100% sure that none of the rust-remover I used, ended up at the valve. I might be wrong, but I really don't think so.
The water in the carbs sounds interesting, anyone on here used it on a motorcycle?

[11csive]

I did some work on the bike yesterday.

Just an out-of-the-box thought here, but maybe that number 2 valve cannot close all the way because of excessive carbon build-up around the stem, preventing it from going just that little bit further into the bottom of the valve guide?

I would try scratching the carbon from the valve stem with a piece of hard wood sharpened to look like a chisel point, or something similar. Even careful use of a metal chisel should not damage the valve stem. While your wife is not around, use the vacuum cleaner to suck out the loose bits of carbon.

Just something to try before you go stripping the head.

I removed as much build-up as I could. Then had a look at the the clearance again - no difference unfortunately.

OEM Suzuki gaskets are best.

Regarding the shims, only 1E & 2E need to be touched. Either that engine is low mileage or someone cut the valves and shortened the stems.

If you can't see anything under #2E when you pull off the exhaust the next step is to pull the cams and remove the 2E bucket to see what's going on there. Key thing to look for is to make sure the valve stem sticks up above the keepers. If someone cut the valve stems too much the keepers may be sticking up too far.

So I pulled the cams, and had a look under the bucket. Stem seems to be properly placed compared to the keepers and nothing else seems off course.

For now I think that there's nothing else to do, than take the engine apart, and have a look at the valve. I'll keep you guys updated. Thank you for your help.

[11csive]

Another sunny day off work, another day spent on the bike

Finally had the time to pull the cylinder head, and have a look at the valve causing troubles. You guys suspected a bent valve, so question is. Is it bent? Oh yes, clearly.

Just to show you guys, I placed it on a flat surface, snapped a picture then rotated it 180 degrees staying in the same position as on the first picture, and it clearly shows.

Stem pointing left.


Rotated it 180 degrees, now pointing to the right.


Definitely needs a replacement. So question is, what do you guys recommend replacing when doing a valve replacement? What parts should I order together with a new valve? And what is the necessary steps to get the new valve to seal properly around the seat?

There's a valve replacement guide on bikecliff's site, the link seems broken however. Any help would be appreciated.

Oh and also. How is 1 valve out of 8 bent? Anything I should check on the engine (besides of course timing) that could be doing this? Or did someone working on the bike earlier mess something up?

[Nessism]

Hum, that's a strange one. Not sure what could cause that other than if the cam chain tensioner jammed up and the valve hit the piston.

Most likely the installation of a new valve will fix things up. I'd pull all the valves, clean them up, check straightness by chucking them in a drill motor, lap them into the seats and replace the valve stem seals. If you want to really do a bang up job find someone with a centerless valve grinding machine and have them kiss the seating surface and backside of the stem to true them up perfect like. During lapping you can verify the valve is sitting the seat properly. If everything looks good you should be ready to run.

[11csive]

Hum, that's a strange one. Not sure what could cause that other than if the cam chain tensioner jammed up and the valve hit the piston.

Most likely the installation of a new valve will fix things up. I'd pull all the valves, clean them up, check straightness by chucking them in a drill motor, lap them into the seats and replace the valve stem seals. If you want to really do a bang up job find someone with a centerless valve grinding machine and have them kiss the seating surface and backside of the stem to true them up perfect like. During lapping you can verify the valve is sitting the seat properly. If everything looks good you should be ready to run.

Ordered all the gaskets, the valve and so on. Waiting with anticipation Also bought some valve grinding paste and made a homemade lapping tool - only waiting for the shipment to arrive.

While I'm waiting I'm spending some time on the exhaust and carbs. Let's start with the carbs. Had a lot of fun dissassembling them for a cleaning and new o-rings + gaskets. (Or not).



2 out of 4 pilot fuel screws are broken, the other 2 bend. Don't know how to get my hands of 4 new ones besides ordering them from the us, which will cost me around 100 bucks including shipment, taxes and import fees. (I really don't like the idea of this to be honest). How is shipment for 4 needles nearly 25$ ?

Another thing. Looking to get myself a 4-1 exhaust on the bike. I measured my pipes to be 35mm, and think I read somewhere that that's the same as a gs1000 (79-80). Can anyone confirm this? Will I be able to put downpipes made for a 1000 on my 550? The reason I'm asking is that I'm able to get my hands on a 4-1 downpipe/collector for a gs1000 for a reasonable price, and then I'm able to fit whatever silencer on there that I like.