1981 gs450s

[Larry D]

Picked up this one for $250 !! Missing side panels and front fender and hasn't run in three years, but, I couldn't pass it up !!



After I got it home we started to get to know each other.



I was told that it may be an "S" model, so, I took some pics of the tabs that used to hold on the cowling.





Here's a pic of the engine number that may help to identify if it is an "S" or not.



Here are the carbs all apart and loosened up awaiting a carb kit from Mr. Barr and I did figure out how to remove this crazy big airbox.





I did snap off an exhaust bolt, but, that's a project for another day. I also stopped by the BMV yesterday and got the title transferred.

 

[Big Rich]

Of course I'm signed up. Carry on, sir.

 

[Larry D]

I just did a rough pricing on what I'm going to need as far as mechanical parts go and it's approx. $160........so far.

 

[Guest]

Oh I'm subscribed indeed Larry! Parts pricing sounds good to me

Take care with that fuel T that joins the carbs... mine was fine until after I had cleaned and re-assembled and then I discovered it was sealing correctly and leaked so I had to get a new one.

 

[terrylee]

Good buy, love the wheels! terrylee

 

[Larry D]

With the help of a 10mm fine threaded bolt and some compressed air, I got the front caliper apart, it was a bit nasty in there.

Time to order some parts......

 

[Guest]

Looks very similar to how mine was Larry... a new piston/seal, a good cleanup, and she should be good as new

My M/C was screwed and the bore was pitted etc. so I got a new one from Mikesxs.com which had a slightly smaller piston diameter (12.7 vs. 13mm I think) and it actually improved the feel quite significantly over stock IMO.

 

[Larry D]

Thanks Pete, I'll check it out because I need a new master cylinder too. My question today is...... How does one re-assemble the caliper ? Is there some kind of way to do it properly ? I tried to put mine back together last night and ended up ripping the boot.



Also got the petcock off and cleaned up. It is missing the filter and it's untested, so, I'm not sure if it's good or not.

 

[Griffin]

It's missing the filter because it's the wrong petcock. That petcock is for a GS850/1000G, and the filter tube that came on it is probably too tall or too wide to fit properly.

The 450E/S models have their own unique petcocks that look like this:

 

[Larry D]

Okay, that explains it then. Thanks Bret.

Is there no vacuum port for the OEM petcock ?

 

[Griffin]

Okay, that explains it then. Thanks Bret.

Is there no vacuum port for the OEM petcock ?

It's on the back, along with the fuel line port.

Vac points up, fuel points down.

 

[Larry D]

Gotcha. I thought it was a dumb question, but, I had to ask....

Do you still have my number Bret ? It ends in 4012. If you're not doing anything Saturday, I was thinking of riding out and getting those side covers and fender.

PM me.

 

[Guest]

Yep Larry, definitely not the right one!

As for getting the piston in... yes there is definitely a technique!

I can't remember who wrote it up now but on here somewhere is a good technique.

It involves getting the caliper all cleaned up ready to go with the new seal in place first. Lube the piston bore and seal with some brake fluid.

Then you lube up the piston with some brake fluid and get the dust boot slipped up from the bottom of the piston just enough so it doesn't pop off.

Then you gently work the flange of the dust cap into the groove on the caliper. I use a small flat blade screwdriver to do this but you need to be extremely careful or you'll rip it.

Once that's done, you can get the piston in and seated properly which should force the dust boot up and into it's groove on the piston.

Hope that makes sense...

 

[Larry D]

Thanks Pete, I'll give it try, except I had to order a new rubber boot.....I actually ordered two, in case I rip it again.
I should have just cleaned and blew out the caliper and left good enough alone, it wasn't that bad to begin with.

 

[Guest]

Actually I need to order another myself, I keep forgetting!

Last time I cleaned and re-greased the axles I discovered a small tear in my dust boot... good idea buying two

 

[Larry D]

I received my o-ring kit from http://www.cycleorings.com/ last night. Thanks Robert !!

I had already separated the carbs and had them loosened up. All I had to do was figure out where the idle mixture screw was. On these carbs the screw is on the outboard side of each carb and are sideways instead of vertical like every other carb I've seen. Mine still had the caps on them, but, after a bit of drilling (see what I did there ?....) and a drywall screw to pull out the cap, all was good. The first carb is swimming in Berryman's now and the other will go in this evening.



I also discovered that taking a picture in macro setting works pretty well as a magnifying glass. I had just sanded and painted the battery box, hence the black spray paint on my thumb....



Just waiting on a myriad of parts to arrive over the next week or so and then the real fun begins !!!

 

[Guest]

Excellent Larry! Now while those carbs are apart... if you want to wake them up a little, drill the slide vacuum port out to about 3mm and chop about 20mm off the slide spring.

The improvement in response is worth it

And if you replace all those cheese headed screws with allen heads, you won't have to remove the carbs to do any jetting changes. Float bowls can be done in place, and the needles can be done simply by lifting the tank.

Oh, and float height... Clymer and Haynes are both wrong! They should be 26.6 +/- 1mm.

 

[Larry D]

I had a fun weekend with the '81 GS450S. First, I got the carbs all back together with new orings.



I also did, what I consider, one of the more difficult jobs completed. Removing those boots is a pain !!!!



I bought one of these from Harbor Freight and did this.









I got a shipment of parts which included the new petcock. I did some general cleanup and began looking at the electrical system. It appears to be in pretty good condition other than there is two different coils. More to follow.

 

[Larry D]

My main question from the weekend is how are the footrest bolts removed ? This bolt will loosen and as it continues to turn left, then, it will tighten again..... Is there some kind of weird captive nut on the back ? I took a good look and it seemed just like a regular bolt to me.

 

[Nessism]

Regarding the caliper piston boot, one technique that works is to slide the boot over the piston and work it down to the edge of the closed end. Install the lip of the boot into the caliper groove, then insert the piston into the caliper body bore and push it in. The boot will slide up as you do so. Last thing is to assure the lip of the boot engages with the groove in the piston.

As for that spinning bolt, take a peek behind the footpeg bracket. Most likely there is a nut you need to hold with a spanner.