GS450s Build - Scrambler maybe? Let's get it running first.

[CDC]

Hello all, great forums, been poking around a bit reading up on my new acquisition, a 1981 GS450s. It cost a whopping $125 and as you might expect it has been sitting and neglected for some time. I'm now at the stage where I decide if it's going to be parted out or rebuilt, so I'm hoping you experts out there will help me get over the hump and make my decision.

First things first, can anybody positively ID these pod filters?



Just gave them a quick wash and there are no marks on them...

The bike also has a Vance and Hines 2-1 exhaust fitted, so clearly the previous owner fancied himself a "tuner."

However, the carbs were an absolute mess, gummed up worse than I've ever seen, air screws 6(!) turns out, and what seem to be the stock jets still installed. Carbs are now clean and I am wondering where to start on my jetting quest here. Doubt it will even fire with this setup.

When I get this figured out, our next topic of discussion will be electronics, or, why does the starter button do nothing? Dash lights come on and I bridged the solenoid with a wrench and got it to crank for a second so at least I know it's not totally seized. If I were going to turn the crank with a wrench, anybody know which cover to pull?

[Flaming Chainsaws]

Since there are no marks on, I would say that they are APE filters.

To crank the engine by hand, remove the right hand side circular cover. Then just get a wrench and turn clockwise.

If you ever want to sell that 2-1 exhaust, let me know .

Welcome to the forum and good to see another GS450.

[CDC]

Since there are no marks on, I would say that they are APE filters.

To crank the engine by hand, remove the right hand side circular cover. Then just get a wrench and turn clockwise.

If you ever want to sell that 2-1 exhaust, let me know .

Welcome to the forum and good to see another GS450.

Good stuff on the filters. Not sure if I should try to salvage them as they're clearly old, but they don't seem to be dirty on the inside where it counts.

Anyway, I pulled the plugs and squirted in some oil, pulled the side cover and the engine turned over nice and smooth with a 19mm wrench. No grinding banging or otherwise unexpected noises and it was definitely moving air.

Got a battery trickle charging right now and I will try to sort out the starter issue tomorrow. It looks like the clutch idiot switch has been disconnected and bridged, but it's possible that was some previous poor soul's attempt to trouble shoot. I'm thinking I need to have a look inside the starter button/kill switch for a bad connection.

[Flaming Chainsaws]

Your starter button does nothing?

Did you do this?

Turn the key on. Flip the kill switch to RUN. Pull the clutch in. Then hit the start button.

If nothing happens, I would say the problem is a dirty start button, clutch switch disconnected or bypassed wrongly. Or the starter solenoid is faulty.

[Big Rich]

CDC, where are you from? I "might" have a stock airbox from a 450 L you could have if needed. Don't know if it will fit or not though.....

[CDC]

I'm in DC. I'm going to run pods one way or the other I think, I just might get newer better ones if these are known to be junk.

Jetting is likely to be a minor headache, but I'm willing to screw with it for some more ponies. I want this motor to breathe!

[CDC]

Your starter button does nothing?

Did you do this?

Turn the key on. Flip the kill switch to RUN. Pull the clutch in. Then hit the start button.

If nothing happens, I would say the problem is a dirty start button, clutch switch disconnected or bypassed wrongly. Or the starter solenoid is faulty.

When I had e solenoid go bad before it made an audible :thunk: when I hit the button. This does absolutely nothing. As I said, going to play with it more tomorrow.

[Flaming Chainsaws]

I'm in DC. I'm going to run pods one way or the other I think, I just might get newer better ones if these are known to be junk.

Jetting is likely to be a minor headache, but I'm willing to screw with it for some more ponies. I want this motor to breathe!

If you don't want those pods you have now, I'll take them. Anything is an upgrade over my current junk EMGO pods.

I also have an extra starter solenoid if you find out that yours is bad.

[spyug]

The starter button contacts are likely gummed up. You can test this with a circuit test lamp on the contact in the wiring harness that connects to the solenoid. There will be two wires. I'm not sure of the colour code on yours but the black or black/white will be ground so check the other one. With the key on depress the button and the light should come on in the circuit tester if not the button contacts need cleaning.

Its very common and I think I've had to clean the last three bikes I've done.

Now if you get power there and the solenoid still doesn't engage then the solenoid is suspect. Sometimes things inside get stuck so you can rap on it a bit with a screw driver handle. If still no go then time for a new one. You can use one from a garden tractor and they are available at Lowes for about $12 down your way ( for some reason they are higher up here@ $15).

With the old bikes that have sat, electricals is usually always an issue so you should clean all contacts and or replace those that are really bad. Poor grounds are another source of frustration so make sure they are clean and making good contact.

When you get it running the first thing to verify is the chargiong system and a review of the Stator Papers will take you through the checks. Bad R/R modules are very common and can cause things like over voltages that can kill batteries and igniters so make sure yours is working correctly before you end up with an issue.

Since pods and "sports" exhausts create lean conditions make sure your carbs have richer jets installed. From your description of the POs abilities they may or may not be. If its running lean you will have a hard time starting and running without a lot of farting and backfiring.

Enjoy the new ride .

Cheers,
Spyug

PS Pics please!

[Guest]

Mate welcome to the forums! A 450 scrambler build hey? Could be a plan for sure! I'm attempting one myself at the moment, although it's temporarily on hold due to time and $$$ constraints.

The only scrambler type things I've successfully got done so far is adding fork gaitors and a cardboard mock up of a high 2 to 1 pipe.

As for those pods, no idea, but I've gotten myself some K&N's as they're known to be a good filter for working out consistent and reliable jetting sizes.

With your starter button, if the relay is giving a good "clunk" when you hit it, chances are the solenoid is good but the starter motor brushes or something are bad.

First test is to short the two big posts of the solenoid which will feed battery voltage direct to your starter motor.

If that kicks the starter into life, it's your solenoid.

If it doesn't, then it's likely your starter motor.

I haven't had to do it myself, but I'm pretty sure it's possible to dismantle the starter motor and clean up the brushes etc. inside which is most likely all that's wrong with it and will be cheaper/easier than trying to locate a replacement starter.

Good luck and keep us up to date on progress!

We like lots of pic's too

[Flaming Chainsaws]

gsmotofan is selling a pair of K&N pod filters just like Pete's. Give gsmotofan a PM about the filters he's selling.

Now, how about some pics of the bike?

[CDC]

Thanks for the info guys, the starter button was in fact the problem. Some kind of insect nest was preventing good contact. Stripped it down, cleaned it up and she cranked over nicely.

While I was in there, I slapped on my compression tester and got a reading of just under 150psi on both cylinders. I assume this is within spec?

Anyway, put a new pair of plugs in and she has good spark. A quick shot of starter fluid and she fired up instantly and actually sounded pretty good. No excessive valve/chain noise or rod knocking that I could hear in the 3 seconds it was running.

Right now I'm working on the tank. It was pretty rusted out and dented, so I stripped the paint, welded up a few pinholes and pulled the major dings out as best I could.



Tomorrow the welds will get ground down, I'll sand the whole thing, and spray it with clear coat. The inside is going to need another rinse too after the welding I think.

The bike won't be much to look at till I get the major components reinstalled, but rest assured, more pics will be coming.

[CDC]

Quick update,

Ended up ordering a 6 Sigma (?) jet kit for about $50 on ebay rather than spending 3 weeks shipping individual brass back and forth. It's my first time doing a kit rather than manually jetting but I just don't want to spend the time screwing with it at this point in the season. Will report on the quality of the kit and try to get her running on her own power early next week.

A few odds and ends need to be sorted out before then (loose shifter linkage, no front brake, seized speedo drive, and a bit of rust) but nothing especially glamorous or complicated.

I do have another question, do the head and tail lights only come on when the bike is running or do I have more electrical diagnosis in my future?

[Flaming Chainsaws]

On my 1980 GS450L, the headlight and tail light turn on even if the bike isn't running.

[Guest]

Mine has a switch on the right controls to turn the lights off... if there's no switch I would imagine they should be on with the ignition on though.