1981 GS450E Rebuild

[Suzuki_Don]

I figured I'd skip trying to do anything with the engine mount tonight . . .

So, decided to get a start on the carbies now that I have some carby cleaner dip, although I still need a sauce pan and some spray carby cleaner.

Pete I diluted the Yamaha Carb Cleaner at a ratio of 3 parts cleaner to 1 part of water. And then just boiled it up on the porta gas for about 20-30 mins.

 

[Guest]

Cool cheers Don, saw that in my carby dip thread and hopefully I'll get myself a Saturday in the next week or two when I can actually do the boiling once I find an old saucepan or whatever.

Fortunately we have a portable gas hot plate for blackouts so that side of it is nice and easy.

 

[Suzuki_Don]

Cheers for the quick tutorial Don, much appreciated. As per my PM I did work it out though... it's an imperial micrometer with metric instructions

Now, as to what shims and clearances I have, here's the list:

Left inlet: 2.60mm with what feels like some contact, bucket rotates but with difficulty.

Left exhaust: Exactly the same as the left inlet, this is the unmarked shim that I now know is 2.60mm.

Right inlet: 2.65mm, no contact, but less than 0.04mm clearance.

Right exhaust: 2.55mm and there is definitely contact with the shim, the bucket doesn't rotate very easily.

I'm pretty confident I could safely go 2.55mm for the left side, but I'm not sure if a 2.50mm would be small enough for the right exhaust or if I would need a 2.45mm, although my gut feeling says 2.50mm would be ok.

So, I believe I would need to procure (swap, buy, loan, whatever):

1 x 2.50mm - right exhaust
1 x 2.55mm - left inlet or exhaust

I can then move the right exhaust (2.55mm) to the left inlet or exhaust and the left inlet or exhaust (2.60mm) to the right inlet.

Does all that make sense and seem to be right? Some of it is guesswork unfortunately, but I don't know how else to work it out.

Well Pete that wouldn't have helped having the wrong instructions for the micrometer. Glad you got it sorted.

BTW I have a 2.50 shim if you want to try it. Although it would take time to get there from Sydney. Depends how quick you need the shims. You may be able to pick them up from the Suzuki dealer if you need them quicker, although Express Post should get there the next day. Unfortunately I don't have a 2.55 shim.

 

[Guest]

Well Pete that wouldn't have helped having the wrong instructions for the micrometer. Glad you got it sorted.

BTW I have a 2.50 shim if you want to try it. Although it would take time to get there from Sydney. Depends how quick you need the shims. You may be able to pick them up from the Suzuki dealer if you need them quicker, although Express Post should get there the next day. Unfortunately I don't have a 2.55 shim.

Thanks for looking Don. I'm in no particular rush as i have yet to sort the carbs and clean up the wiring harness before even thinking about firing it up.

However, having said that, I may look at buying some as I definitely need another 2.55mm and I think it would be best for me to get a 2.45mm just in case that one valve is actually being pressed down a little.

There was a thread here somewhere a few weeks ago about a place in Melbourne that sells suitable shims for a good price so I'll check with the dealer and if they're ridiculous I'll try the Melbourne mob as they do shims for all sorts of vehicles apparently and they have some suitable diameter for our GS'.

 

[Guest]

No progress update as expected, but we did successfully pick my wife's new (to us) car up and she's real excited about that and I must say it's in pretty good nick for its age.

I did however end up ordering some shims yesterday.

I couldn't find the thread on here about the shim place in Melbourne and I seem to recall it was in the wanted/for sale section so it was likely purged, but I did recall the word Precision in the name, and they're Precision Shims Australia.

So, three shims posted for $41 in a satchell so I should have them very soon, maybe even the end of this week if I'm lucky.

I ordered 29.5mm flat shims, 1 x 2.45mm, 1 x 2.50mm, and 1 x 2.55mm, so I should be set hopefully, as long as I haven't screwed any of my measurements up or gotten confused between inlet and exhaust. I find myself quite often thinking inlet is the front of the engine which is just plain wrong.

 

[Guest]

Quick update, no pic's at the moment though.

Had a spare 5 min's while waiting around, so I got the float pin out of the left carb and took the float cover off and got the pin out from the right carb also.

Sharpy's advice was to get a mate to hold a flat blade against the pin post while tapping it out to avoid breaking off the post.

Unfortunately as luck would have it my house mate was out when I had the 5 spare min's, but I was able to support the post by putting a flat blade against the wall at the back of the workbench and using that to support the post by holding the carb against it. Seemed to work well and the pin came out with gentle yet firm little taps with a hammer on a very small pin point screw driver. I simply increased the pressure of the taps very carefully until it budged and then it came out very easily.

The right pin came out without any need for the hammer at all, it just slide out with the pressure of the pin point screwdriver.

 

[landshark]

Its Australia day mate, dont do too much work.

 

[Guest]

Definitely not! Bit, err, not quite sober right now... finally had a nice Qld day today to sit in the pool and the spa and dreink beer... nice

 

[Suzuki_Don]

Seemed to work well and the pin came out with gentle yet firm little taps with a hammer on a very small pin point screw driver. I simply increased the pressure of the taps very carefully until it budged and then it came out very easily.

Pete it's a good idea to dress down the thick part of the float pin so when replacing it in the post it is not as firm a fit. Even if the pin is loose in the post holes it cannot come out because it is held in place by the shape of the fuel bowl. Just dress it down so it is a gentle push fit, makes it easier to pull out next time and no broken post.

 

[Guest]

Pete it's a good idea to dress down the thick part of the float pin so when replacing it in the post it is not as firm a fit. Even if the pin is loose in the post holes it cannot come out because it is held in place by the shape of the fuel bowl. Just dress it down so it is a gentle push fit, makes it easier to pull out next time and no broken post.

Cheers for the tip Don. Not real sure if I have the tools to take care of that, but I'm guessing a bit of a rub with sand paper will be sufficient.

 

[Suzuki_Don]

Cheers for the tip Don. Not real sure if I have the tools to take care of that, but I'm guessing a bit of a rub with sand paper will be sufficient.

Yes Pete, sandpaper, flat mates emery board for his nails, a small file (fine cut), pretty much anything will do. Not a big job.

 

[Guest]

Yes Pete, sandpaper, flat mates emery board for his nails, a small file (fine cut), pretty much anything will do. Not a big job.

Good stuff Don, nice and easy. I'm sure the house mate will love it when I ask for his emery board, probably get a good one upside the head! haha

Plenty of sand paper around and I need to start sanding and painting the oil filter cover too otherwise I'll get the valves, carbs, and wiring done but still won't be able to fill it with oil.

 

[Guest]

Here I am reading through various threads on here, and it has finally dawned on me (sometimes I'm a tad slow).

When I last had the bike running (that was a while ago, like 9 years), it was a bit hard to start.

There was even a time when I couldn't start it and it would just keep cranking until the battery was flat (4am after a 12 hour taxi shift).

At that particular time I ended up re-gapping the spark plugs because they were way too big, but it still wasn't real easy to start.

Now, after doing my valves, I have no clearance on three of them which makes me think there would've probably been a little clearance before getting them faced but not much.

So, I needed a valve adjustment years ago... if only I had've realised it way back then!

 

[Guest]

Present in the mail today:



Man that was quick! Ordered them Tuesday, here today with a public holiday in between, didn't expect him to Express post but glad he did!

The white cable tie there is for the cable tie method of valve adjustment:



And three shims all in a row:



So, left inlet was the first to get done as I needed to get the 2.60mm shim out from that one to put into the right inlet. The new 2.55mm is going in here.

Crankshaft rotated so valve is depressed:



Rotated back so the lobe is up again and lots of clearance to remove the shim:



Just realised how horrid that cam lobe looks, but they're all smooth, so running in the oil should clean that up I would imagine, certainly don't want to sand it or anything.

Here's how the cable tie sits in there holding the valve down for the clearance above:



That let me remove the 2.60mm shim very easily, and here it is compared with one of the new shims:



I must say I like the way they mark the new after market shims I got as opposed to the OEM ones.

I then did the same for all the others, and man that cable tie method is so nice and simple and easy!

I ended up with 0.05mm clearance on both inlet valves, left with 2.55mm shim and right with 2.50mm shim, but unfortunately the exhaust valves still seem to have no clearance, even though the left went from 2.60mm to 2.55mm and the right went from 2.65mm to 2.60mm. I've obviously messed something up there for sure.

I ended up sweating like a pig in the garage tonight so had to call it quits before finalising the adjustments, so I do need to go back and fix the exhaust valves yet.

I did snap a couple of quick pic's of the carby float pins removed too:



All in all, limited success, but I know how to do the valve adjustments now and it's very straight forward and will get easier once I know what clearances I have with what shims. If I had've measured them before tearing it down in the first place, I would be able to make much more accurate decisions on shim sizes now. Oh well, them's the breaks.

Not sure when I'll get back to it just yet, night out on the town tomorrow night and have to go into work for an upgrade 2pm Sunday avo. Hopefully I'll get some time Saturday or Sunday night, although if it's Saturday daytime then I really hope I can get a saucepan first so I can boil the carbs.

 

[Suzuki_Don]

but unfortunately the exhaust valves still seem to have no clearance, even though the left went from 2.60mm to 2.55mm and the right went from 2.65mm to 2.60mm. I've obviously messed something up there for sure.

Pete you need to swap the two exhaust valve shims and that should make the right cylinder correct or closer anyway. That means it would be coming down from 2.65 to 2.55 instead of 2.60 which is an extra .05mm clearance. After this swap is done check the clearance with the feeler gauge to make sure it is OK. Then you will need to order a 2.50 shim for the left exhaust valve.

This should make them all OK, but there's no guarantee when doing the valves after a rebuild. Unless you have an ultra thin shim to put in to take measurements with, then you have to pretty much experiment because if a valve is a bit tight you don't know whether you need to go down one size or two to gain the correct clearance. I have a 2.25 shim I insert and get the measurement with the feelers and from that I can work out what size shim I need for the respective valve. I also have about 30 shims counting the ones in the engine currently so I have a good selection for my own use. I was lucky in that I picked up a couple of cylinder heads on the cheap and they all had shims in them.

 

[Guest]

Pete you need to swap the two exhaust valve shims and that should make the right cylinder correct or closer anyway. That means it would be coming down from 2.65 to 2.55 instead of 2.60 which is an extra .05mm clearance. After this swap is done check the clearance with the feeler gauge to make sure it is OK. Then you will need to order a 2.50 shim for the left exhaust valve.

This should make them all OK, but there's no guarantee when doing the valves after a rebuild. Unless you have an ultra thin shim to put in to take measurements with, then you have to pretty much experiment because if a valve is a bit tight you don't know whether you need to go down one size or two to gain the correct clearance. I have a 2.25 shim I insert and get the measurement with the feelers and from that I can work out what size shim I need for the respective valve. I also have about 30 shims counting the ones in the engine currently so I have a good selection for my own use. I was lucky in that I picked up a couple of cylinder heads on the cheap and they all had shims in them.

Makes perfect sense thanks Don and is what I was thinking about last night and earlier this morning.

I did order the extra 2.45mm shim which is currently sitting on the work bench so I can use that to work out what I need hopefully.

 

[Guest]

Rightio, back at it tonight, and I now have three out of four valves done.

I popped the spare 2.45mm shim in the left exhaust, and still less than 0.04mm clearance. I just realised I didn't check if the bucket rotates easily or not, so not sure if I should go down 1 or 2 sizes.

Anyway, I popped the unmarked 2.60mm shim into the left exhaust for the time being and tried the 2.45mm shim in the right exhaust. 0.06mm clearance! Yay!

I believe I should get myself both a 2.40mm and 2.35mm for the left exhaust to allow for either one or two sizes down.

Here's a gratuitous pic with no merit at all as to what was done tonight:



So, after my 50% success rate there, I decided to clean up and mount the top cam chain guide in the valve cover.

Dirty:



No guide:



Clean:



Guide:



I used thread locker on the screws just in case. Don't want them coming out and letting the guide float around in there!

And back onto the carbs again.

Firstly, had Asia Canteen for dinner on Saturday night and whacked the containers through the dishwasher because I have a use for them:



House mate also managed to score me a nice sized sauce pan for $5 as I've had no luck finding cheapies:



So, this is where they were left:



Needle valve assembly removed:



Quite disgusting in there really... but what can I expect from 30 year old carbs that have been sitting idle for 9 years?

 

[Guest]

I wasn't able to get the needle jet to move at this point, so I left it and moved on for the moment after squirting it liberally with some WD.

Onto the diaphragm cover and diaphragm:



Not as bad as I thought in there, but still not nice:



Onto the choke plunger:



And this is for my reference of how the spring hooks onto the left carby:



Assembly off, and another pair of gaskets to obtain:



At this point I sorta stopped taking pic's so much because Flaming Chainsaws' guide really covers this off and I was having trouble getting the camera to focus properly in the crap light I have to deal with in the garage.

I did take note of how many turns out the pilot air screws were, which was 2 1/4 turns for the left carb and 2 turns for the right carb.

I removed those, then removed the pilot jet and main jet from the float chambers.

I then removed the boots from the airbox that were still attached as well, which left them quite messy indeed:

 

[Guest]

Ugly:



And that's where they sit, so close to being ready for cleaning:



So, I need to run through the cleaning and inspection part of the Clymer and revisit the carb cleaning guides around the place including FC's to make sure I've got everything covered off.

I need to get the needle jets out too as they're still stuck quite firmly in there at the moment.

I also need to start tracking down some nice stainless allen head bolts for the carbs and think about if I'm going to paint or polish them also.

 

[Charlie G]

Pete,

Thanks for the carb pictures. I need to do this to my 450 this year, as I pretty sure I have some air leaks somewhere in the system. Where does FC have his carb rebuild listed. Is it in his 450l rebuild thread? I'll have to poke around. What is all that amber colored junk on the intake side of the carbs? Looks nasty!

cg