Help/tips to improve my 92 1127

[Canada1127]

Just joined. 

Rick from Alberta, Canada

Casual rider, who likes to open up when roads are clear.

Have owned my 92 GSXR 1100 (1127) for over 20 years (3rd owner).   83K kms on odometer.

Freshening it up- repair plastics, new paint, new signal mirrors,  theme it (53 going on 14).

Not a mechanic.  So trying to figure the finer points of keeping it running nice.

Carbs were rebuilt not long ago.  Just removed them, cleaned and reinstalled, after it sat for a while.

Hooked an auxillary tank up and she started and ran not bad.

At idle below 2000 it tends to want to stall.  Don't want to keep idle high and be slamming into gear all the time. Or waste fuel.

What can be done to make this better , FOR NOW.   Just want to ride it a bit, before winter is back.

Valves have never been checked (daunting to me), but likely need to be adjusted.  Difficulty?  But would prefer to do over winter.

Thinking to get a vacuum gauge set and check/sync the carbs, and maybe improve low rpm idle?

Cylinder compression for age and kms isn't bad .  Good range.

130/135/140/135

Look serviceable?

Does taking exhaust pipe temps give an indication of how well each carb is set (rich/lean)?

Tips are very welcome and appreciated!

Before and after photos.

Cheers

 

 

 

[Gixer1460]

At that age it'll have shim adjusted valves - not really a beginner mechanic job IMO and they are probably why compressions are a bit low. Bad running carbs at idle / low speed will no doubt be idle jets - need solvent and / or ultrasonic clean to be sure.

[bluedog59]

 

Unfortunately there is no point in balancing and setting up the carbs if the engine needs a service and the valves adjusting etc. I would say that checking and adjusting the valves is not beyond the average person if you can read a manual and tell one end of a spanner from the other so, get a manual and read it.......then read it again. 

Things required for the job,

Time so you're not rushed.

Space, especially somewhere you can leave the job for a while if you need to walk away and take a break. Things are often clearer when you come back.

Correct tools. Money spent on the correct tools is never wasted.

Manual, notepad. Make a chart showing valve number/position, shim installed/gap/shim required.camera to record how things fitted.

A level headed mate for a 2nd opinion.

Triple check everything you do as you go along.

Read the f@cking manual.

Cold beer in fridge for end of job.

If in doubt, ASK !

[Canada1127]

31 minutes ago, bluedog59 said:

 

Unfortunately there is no point in balancing and setting up the carbs if the engine needs a service and the valves adjusting etc. I would say that checking and adjusting the valves is not beyond the average person if you can read a manual and tell one end of a spanner from the other so, get a manual and read it.......then read it again. 

Things required for the job,

Time so you're not rushed.

Space, especially somewhere you can leave the job for a while if you need to walk away and take a break. Things are often clearer when you come back.

Correct tools. Money spent on the correct tools is never wasted.

Manual, notepad. Make a chart showing valve number/position, shim installed/gap/shim required.camera to record how things fitted.

A level headed mate for a 2nd opinion.

Triple check everything you do as you go along.

Read the f@cking manual.

Cold beer in fridge for end of job.

If in doubt, ASK !

 

2 hours ago, Gixer1460 said:

At that age it'll have shim adjusted valves - not really a beginner mechanic job IMO and they are probably why compressions are a bit low. Bad running carbs at idle / low speed will no doubt be idle jets - need solvent and / or ultrasonic clean to be sure.

 

Thanks 1460

Maybe didn't clean passages in the carb body itself.  Did inspect all the jets I pulled out-solvent, air and wire where needed.  Maybe strip it all and soak the body in acetone or the like.

Not afraid to get into the valves, but would prefer to find a video specific to this bike to know how it's goes together versus other ones.  Just watched a good video, and seems to be a numbers game really, and reassemble as you found it.  I'll likely give it a go when it gets cold out.

Thank you sir!

 

[Canada1127]

40 minutes ago, bluedog59 said:

 

Unfortunately there is no point in balancing and setting up the carbs if the engine needs a service and the valves adjusting etc. I would say that checking and adjusting the valves is not beyond the average person if you can read a manual and tell one end of a spanner from the other so, get a manual and read it.......then read it again. 

Things required for the job,

Time so you're not rushed.

Space, especially somewhere you can leave the job for a while if you need to walk away and take a break. Things are often clearer when you come back.

Correct tools. Money spent on the correct tools is never wasted.

Manual, notepad. Make a chart showing valve number/position, shim installed/gap/shim required.camera to record how things fitted.

A level headed mate for a 2nd opinion.

Triple check everything you do as you go along.

Read the f@cking manual.

Cold beer in fridge for end of job.

If in doubt, ASK !

Appreciate the feedback,

Blue dog!

I do as much maintenance on vehicles in general back home.  Haven't delved into engine internals a ton, but a bit.  Shop rates are $$$.   And there's a sense of pride in doing your own repairs.

Watched a detailed video that gave an idea of how it goes.  Watch cam and crank positions.  And then keep track of all your measurements to adjust the valves properly.

Could see it being a winter project.  Set up in a corner of the shop and take my time I guess. 

Probably order gaskets and o-rings, just in case.

Any worth in a leak down test?

 

Again I appreciate your input very much.

 

Cheers!

[bluedog59]

Leak down never does any harm if you have the kit.

[Graeme]

As mentioned, everything else needs to be right before balancing the carbs. But if the carbs have been apart, they will 100% need balancing.

[Canada1127]

6 minutes ago, bluedog59 said:

Leak down never does any harm if you have the kit.

I guess even a basic one will at least give an idea of where compression is being lost.  Kind of irrelevant if I just adjust all the clearances across the board.

[Canada1127]

6 minutes ago, Graeme said:

As mentioned, everything else needs to be right before balancing the carbs. But if the carbs have been apart, they will 100% need balancing.

Thanks Graeme!

 

Agree.  Manometer or vacuum gauge are the best I understand.  The local bike shop a while back said they "adjusted" the carbs (post new parts) by taking temp readings off the exhaust pipes for each cylinder.  After reading a bit, that seems like a lazy back woods way to do it.  Maybe that method could work to diagnose lien or rich air fuel mixture for each cylinder?

So valves, then syncing.  Be a fun winter. 

 

Cheers 

[Dezza]

Shim engines aren't that difficult to work on, especially if they're designed so you can swap shims without having to remove the cams. It really helps having a good pair of tweezers though and one of those telescopic extendable small magnet thingies. And don't forget to block the camchain tunnel with a clean lint-free rag because if you drop a shim down the tunnel this will obviously spoil your day.

[Gixer1460]

Re : leak down testing - whilst the valves could be adjusted spot on, you could still get valve leak down due to pitted / burnt seats or valves! No one has mentioned need for decent micrometer when doing shims. Yes, new ones have sizes etched on them but used numbers unlikely still to be seen. Measuring gaps for each valve then each shim gives a total. Subtract the ideal clearance figure and you get correct shim required. Just seems quicker / more consistent than swapping random shims around?

Oh, and try and find someone with a shim box for replacements - they are bloody expensive for what they are! I had to re-shim a bare head once, cost more than the head was worth!

[Canada1127]

4 hours ago, Dezza said:

Shim engines aren't that difficult to work on, especially if they're designed so you can swap shims without having to remove the cams. It really helps having a good pair of tweezers though and one of those telescopic extendable small magnet thingies. And don't forget to block the camchain tunnel with a clean lint-free rag because if you drop a shim down the tunnel this will obviously spoil your day.

Great advice Dezza

Seems to be a lot of measuring accurately, map which shims go to which valve and take your time.

Haven't worked on valves before.  Sounds like my model is more of a nuisance to do this job on then its predecessors. Do you know if you have to pull the camshafts to access the shims, or is there a way to further compress the valve springs in place to create enough room to remove them?  I only ask this because I saw a YouTube video where a guy was working on GS550 and was able to do that and just fish them out from the top, with the  camshaft in place.

 

Definitely will plug off all the holes to the bottom end, really don't want to do a complete tear down :-). 

 

Thanks again!

 

Cheers 

[Captain Chaos]

7 minutes ago, Canada1127 said:

Do you know if you have to pull the camshafts to access the shims, or is there a way to further compress the valve springs in place to create enough room to remove them?

The manual knows. Buy/download one and read it.

Camshafts can stay in place, the rockers can be moved sideways enough to remove shims.

[Canada1127]

1 minute ago, Captain Chaos said:

The manual knows. Buy/download one and read it.

Camshafts can stay in place, the rockers can be moved sideways enough to remove shims.

 

Appreciate the info Captain!

This information is gold!

I really was hoping the camshafts didn't have to come out so that things would be a lot more straightforward.

I do have a Haynes manual, but it is a little bit light on details. It has the exhaust and intake valve clearance tables but is a lot light on the procedure and steps taken to actually changing them out. Might have to see if I can find a paper factory copy somewhere. Just my preference over digital,  but can definitely open a digital manual in the in the event I can't find one

What gaskets and seals should I have on hand in your opinion - valve cover, oil cooler line o-rings, spark plugs tube seals, seals around the various valve cover bolts. Anything missing?

I appreciate all the comments and feedback that you and your fellow riders have given.

 

Cheers 

[Gixer1460]

Generally no seals required as everything is rubber and re-useble. Only the cover bolt gaskets get a bit compressed so might weep a bit. Careful with the spark plug well gaskets as if displaced you will get an oil leak below the exhaust pipes where the well drain holes exit!

[Canada1127]

8 hours ago, Gixer1460 said:

Generally no seals required as everything is rubber and re-useble. Only the cover bolt gaskets get a bit compressed so might weep a bit. Careful with the spark plug well gaskets as if displaced you will get an oil leak below the exhaust pipes where the well drain holes exit!

Good information.  Sounds like they made servicing them not as bad as I thought (after asking a lot and reading up online).

Nice gaskets are reusable.  I guess I could have bolts washers ordered in.  Or just coat them in a bit of RTV.

Will definitely pay attention to all the little bits and bobs and plug with rags where needed.

 

Thanks very much say what now!? 1460

[Dezza]

No gaskets or seals needed just patience and care, same as most things reallly. Arm yourself with some cotton ear buds and paint thinners to remove the old sealant from  the half moon shaped recesses in the head. You'll have to remove any old sealant from the gasket too. This is the only area you need to apply sealant and it only needs a thin smear.

Be careful reinstalling the 8 cam cover bolts. They are shouldered and when bottomed out will not exert any more pressure on the gasket. They just need lightly nipping up. They thread directly into the cam caps, have an M7 thread and are easily stripped if you go at it like a bull-in-a-china-shop .

[Canada1127]

4 hours ago, Dezza said:

No gaskets or seals needed just patience and care, same as most things reallly. Arm yourself with some cotton ear buds and paint thinners to remove the old sealant from  the half moon shaped recesses in the head. You'll have to remove any old sealant from the gasket too. This is the only area you need to apply sealant and it only needs a thin smear.

Be careful reinstalling the 8 cam cover bolts. They are shouldered and when bottomed out will not exert any more pressure on the gasket. They just need lightly nipping up. They thread directly into the cam caps, have an M7 thread and are easily stripped if you go at it like a bull-in-a-china-shop .

Appreciate the added advice Dezza 

By far the right group to join for this old bike.

Definitely leave it for winter when it's slower here and can just settle into the job.

Cheers 

[Jonny]

On 6/29/2025 at 1:10 PM, Canada1127 said:

Do you know if you have to pull the camshafts to access the shims, or is there a way to further compress the valve springs in place to create enough room to remove them?  I only ask this because I saw a YouTube video where a guy was working on GS550 and was able to do that and just fish them out from the top, with the  camshaft in place.

Ignore this. Wrong tool.

Edited June 30, 2025 by Jonny

[Canada1127]

28 minutes ago, Jonny said:

You need one of these to compress the springs.Then you can just fish the shim out with tweezers or whatever.

Won't know til I open it I guess.  Captain Chaos said this specific year/model rockers just slide over.  Did find a pic of a top end for sale , that gave me an idea how it goes together.  Looks like rockers can be slid sideways, allowing shims to be swapped-hopefully.

 

Thanks Johnny!

 

[Dezza]

Isn't that tool for aircooled GSs?

[Jonny]

2 minutes ago, Dezza said:

Isn't that tool for aircooled GSs?

You may be right. Looking at the picture of the head it doesn’t look like it would work. 

[colinworth79]

The shims can be taken out with cams in place . I just pull the rocker against the spring then drop it down between the 2 valve springs to keep it there while you swap the shim . Measure all the clearances first then make a note on the ones that are out. Worst bit of the job is trying to work out what size the current shim is . As mentioned above they have a number printed on them when new but wear off . I managed to swap a couple about to get the clearances within spec .  

Also if the rocker cover hasn't been off for a number of years I would factor in changing the gaskets . I've not had much luck with 10 year old gaskets keeping oil tight once they  have been disturbed.  

[Canada1127]

29 minutes ago, colinworth79 said:

The shims can be taken out with cams in place . I just pull the rocker against the spring then drop it down between the 2 valve springs to keep it there while you swap the shim . Measure all the clearances first then make a note on the ones that are out. Worst bit of the job is trying to work out what size the current shim is . As mentioned above they have a number printed on them when new but wear off . I managed to swap a couple about to get the clearances within spec .  

Also if the rocker cover hasn't been off for a number of years I would factor in changing the gaskets . I've not had much luck with 10 year old gaskets keeping oil tight once they  have been disturbed.  

Thanks CW79

Slowly able to get a visual of the process from all the help this group is throwing at me.  Definitely do in off riding season, just in case the gaskets are original and not supple any more. If original for a 33 year old bike, assume the worst.

 

The number game I should be able to get my head around.  Think I have a digital caliper here just in case numbers are gone.

3rd owner of it. But no idea how regular maintenance was.  Guilty myself of not checking things earlier.  

 

Thanks for the input sir!

 

Cheers