1985 GS450 starting issues

[dennco2]

Hi, I have owned this bike for 2 months now and have yet to ride it.

It barely started right after purchase but was only hitting on 1 cylinder ... so I pulled the carbs and cleaned them real good and reinstalled. Attempted a start and all lights were on but the starter motor turned over very slowly with NO start, so I pulled the battery out and charged. The battery read 13.2 after charge but the next morning it went down to 12.6. Lights turned on but slow starter and no start. Then I removed the battery ground to the rear of the engine, cleaned and replaced. Now I get NO lights and NO starter movement at all, with ignition on. It's getting worse every time I try to get a start! Either I blew some main fuse or the battery is total crap!

Can I use a car battery and jumper cables to the starter solenoid and engine ground ... to test starter motor without hurting the system?

I checked the inline fuse on the left side and it seemed fine. Is there any other fuses elsewhere to find and check? The top of the neg battery terminal seemed to be touching the battery box, so I laid tape to stop contact there. Behind the battery box is an electrical part I have not identified as yet and a female double connector NOT connected to anything. The wire color looks like black with white stripe. Can someone tell me what that double female black and white connector goes to?

I have ordered a new battery .... as the old one looks a little sulpherized. It charges up fine but loses voltage fast. I was hoping all my work to fix the bike and battery would yield a good start and strong running of the engine today .... not to be. I'm also worried that the starter motor might need a rebuild .... would I have to remove the carbs to get that out? Ouch.

 

[posplayr]

Can I use a car battery and jumper cables to the starter solenoid and engine ground ... to test starter motor without hurting the system?

Only do this with the car engine off.

If you have a voltmeter, measure the voltage right at the battery terminals using the procedure in Quick test in my signature. If you post all of the results, we can probably get a pretty good idea of what is wrong or at least figure out a next step.

B/W is harness ground ; if you got a factor schematic you could see that. Check Basscliff's website; he has many manuals uploaded.

 

[sam000lee]

Sounds like you have a few things going on.
Once you get the starter cranking...
Have you done valve clearances yet? When I got my GS450 I waited on this and it's really pretty simple, lots of help over on BassCliff's site.

The Help your bike won't start! thread might be of some interest to you.

I'm sure somebody is also going to ask you how you cleaned your carbs and if you replaced the O-rings.

 

[dennco2]

Sounds like you have a few things going on.
Once you get the starter cranking...
Have you done valve clearances yet? When I got my GS450 I waited on this and it's really pretty simple, lots of help over on BassCliff's site.

The Help your bike won't start! thread might be of some interest to you.

I'm sure somebody is also going to ask you how you cleaned your carbs and if you replaced the O-rings.

As far as the cleaning of the carbs .... I followed the GS tutorial on this forum as best as possible. Dipped carb bodies and parts, used air pressure to blow dry the jets and passageways.

I just read the Bike Wont Start thread. Lots to digest there. I will be checking valves altho at this point it seems like a daunting task. I have a GS450 manual with supplements.

For now, I just wanted a small victory to get it started and hear the engine run a bit. Yesterday I charged the battery again to 13 volts showing and when I turned on the ignition switch not even the dash lights lit up! (new battery is coming on Tuesday) Past efforts to start showed bright dash lights but very slow starter motor turnover .... like either the battery or starter motor or grounds or ALL of them were in poor shape. So far I have cleaned the battery ground to the engine. Currently I have clean carbs with fresh O-rings including the 40mm, brand new petcock, new fuel and vac rubber hoses, clean tank inside, fresh fuel. I am trying to eliminate the culprits one by one.

Yesterday, I had both my centerstand and kickstand in the down position. Does that prevent a start up with clutch handle pulled? Does the clutch handle have to be pulled ALL the way back to make the starter connection? I don't have an owners manual ... but see that I can download that from the manuals section. The PO said this bike ran fine for his 5 years of ownership ... except for this year so he sold it. He didn't believe in maintenance ... but only rode it about 500 miles total (he said).

 

[tom203]

Try jumping the starter motor solenoid. Make sure bike is in neutral - on centerstand too as backup. Key off . Use a small jumper wire to connect battery positive to the small terminal on solenoid (this is the terminal the starter button operates): solenoid should "click" and starter should spin. This bypasses any safety switches . Note that solenoid frame has to be grounded for even this to work.

 

[Guest]

Is this one of the models that the clutch lever has to be pulled in to start? (some of mine pre date this safety feature, some don't). Have you cleaned the contacts for the clutch lever switch yet? Same switch as the front brake light on mine.

 

[dennco2]

Yes, I found out by surprise that I have to pull the clutch lever to engage the starter motor. I have not cleaned the contacts for the clutch lever .... where is it? I'll clean it asap ... as soon as I can find it.

I am sure my current battery is junk and can hardly wait till my new battery arrives. My OTHER bike sat for a month and the 5 month old battery discharged and went bad on me. I charged it and it showed 13.2 volts but wouldn't even begin to turn over the starter. Plopped a new one in .... and all was well again.

 

[dennco2]

A little update on this starting problem.

I bought a new YB battery and acid and charged it to full. While removing the old battery from the bike ... I noticed the positive battery terminal connector had cracked in half .... so no wonder no power getting to the bike. I crimped and soldered another copper connector on the positive side wire harness and installed new battery .... and got power to every where but STILL not to the starter. It didn't even click the starter relay.

Also I noticed the kickstand light will not go out, even when in the up position. Would that effect the starter situation? Anyway, I am slowly reducing the list of likely causes for starting issues down to the starter solenoid, the positive wire to the starter motor, or the starter itself. Of course the starter switch could be bad too. Can someone direct me to a previous discussion on how to diagnose where the problem is ... or throw out some more suggestions on how to go about tracking down the problem? My knowledge of wiring issues is still quite limited even though I am working on it.

 

[tom203]

". and got power to every where but STILL not to the starter. It didn't even click the starter relay."

Reread my previous post on jumping the solenoid- note the stuff about solenoid case being grounded for even this to work!

 

[dennco2]

Okay, I jumped the solenoid using a spare battery and jumper cables and it clicked and the starter motor spun up. So I flipped on the ignition switch and finally was able to start the engine. As before, it was only firing on the left cylinder and would only idle or rev slightly above it. Stone cold right side pipe.

I should have also tried to start it again by pressing the starter button, but didn't. When I 1st got the bike I could use the button but the starter motor turned over so slowly the engine most of the time would NOT start. Weeks later, not even a click by using the button, even recently after installing a new charged battery. Am I right in suspecting a bad starter switch which needs cleaning?

Previously, I had pulled the plugs and confirmed I was getting spark to both. Then I super cleaned both carbs in and out and remounted ... making the assumption fuel wasn't getting to the right cylinder. Today, after firing the engine up to idle I still have the same problem ... NO firing on the right cylinder. I have an OLD compression tester which just pushes down over the SP hole, instead of threading into it. I need to accurately check compression, so will be looking to buy a good one. Any other suggestions?

 

[tom203]

You still need to clean up your electrical connections,, but progress is good.
As to carbs.... Your "super cleaning" is likely inadequate, but go ahead and explain. These carbs have tiny passages in pilot circuit and once gunked up they resist quickee cleaning methods. You need the pilot circuit clean to get the right carb to get enough fuel or it won't come alive. Have a look here (your 1985 carbs should be similar)

http://members.dslextreme.com/users/cbsaunders/gs/gs450_carb_cleaning_guide.pdf

 

[Oldman99]

These carbs have tiny passages in pilot circuit and once gunked up they resist quickee cleaning methods.

That font joke was funny good sir.

Checking the valve clearance and compression will be the best thing. Most people who buy bikes like ours don't check and if the clearance is already off, things will keep getting worse.

 

[Guest]

Although I've never seen it, I'm sure there is a starter relay in there somewhere. If your battery is charged, the starter button contact clean and everything is grounded as it should be and you can power the starter motor directly and it spins, maybe the relay is toast. They aren't expensive and are easy to install.
I think you carb is still plugged up or way out of sync though.

 

[dennco2]

Today I went out to jump my starter with a compression tester threaded in the hole. I got 115 lbs psi and it seemed to be holding that pressure for a long time after. Is 115 within compression limits and enough to fire atomized gas? I did NOT compare the left cylinder, but could if it is useful.

 

[tom203]

"Is 115 within compression limits and enough to fire atomized gas?"

plenty, BUT there has to be enough atomized gas in there.. You didn't explain your carb cleaning technique

 

[dennco2]

1985 GS450 starting issues

"Is 115 within compression limits and enough to fire atomized gas?"

plenty, BUT there has to be enough atomized gas in there.. You didn't explain your carb cleaning technique

I separated the 2 carbs from the support brackets and removed the bowl covers and all (I thought) jets and adjustment screws and needle jet and jet needle and sliders. Then I submerged the carbs one at a time into Berryman's carb dip. Didn't dip the sliders with the rubber diaphrams. I only dipped the first carb a couple hours ... as it looked clean on the outside. The other carb I dipped overnight.

Turns out I missed removing the choke plungers ... the Pilot air jets and the Pilot mixture screws and those parts didn't get the benefit of the dip solution. Later, I pulled those assemblies apart and squirted spray carb clean in there and used a can of compressed air to blow out those areas. No, I am not sure all those passageways are completely clean and clear. I was kinda learning as I went along.

I did soak all the jets and and small holes and passageways and inspected. Pretty confident about those parts. Put it all back together and no fuel leaks when new fuel was supplied through NEW Petcock and fuel lines.

But I agree, it seems fuel may NOT reaching the right carb! The floats were both set the same at .910" ... inverted measurement from the bowl gasket area (without the gasket) .... to the rounded part of the float bottom. Previously were at .800" or so. The 85 carbs seemed to have slightly different specs and the floats were made out of some kind of black plastic instead of soldered metal.

I guess I could open the drain plug to see if there is any standing fuel in the bowl? If there isn't it seems the likely suspect is the pilot air jet passageway? I seem to remember holding that up to the light and seeing a clear hole, but that was 2 months ago now.

I'm open to removing the carbs and doing another cleaning and thorough inspection, if needed. I'm hoping there is a easier solution to get the right side piston to fire. I will check the spark again with the removed plug.

 

[tom203]

Can you post a pic of your carb, so we can determine if you have removed the cap over the idle/air mixture screw (to get at the screw itself) ? Earlier 450 carbs had a different setup apparently.
Your bowls could be full but fuel mixture might not make it up the idle circuit passages to carb throat. See pic to note how mixture squirts out over throttle plate area

After you did your cleaning and put everything back together, did you bench sync the carbs to make sure both throttle plates were equally just about closed when resting on idle stop screw?

 

[dennco2]

Yes, I checked the 2 throttle plates and they close and open together ... and look synchronized with no extra play.

The mixture screw cap was already removed. After a brief cleaning, I screwed it back in and opened both screws out 2.5 turns. I will go back and check those settings. I took a lot of before and after cleaning shots of the carbs. I will post a pic ... if I can figure out how to on this site.

Also, I found a great teaching resource on youtube for GS carb operation.

https://www.youtube.com/watch?v=wyspAHrMbb8

 

[tom203]

"After a brief cleaning,"

These tiny passages don't always respond to "brief" cleaning- that's why folks on here talk about the 24 hour dip. Some folks have to do it twice! Stuff could be jammed up somewhere on path back to fuel bowl. Or Look for an ultrasonic guy near you who has experience with carbs. Without a clean pilot circuit, these things run poorly.

did you get the o-ring kit from cycleorings.com ? 30 year old o-rings are past their sell date. I don't know if the 80-82 kit is the same as the 85 version, but inquire (he's a member on here)- good info on his site

http://www.cycleorings.com/450.html

 

[Steve]

Also, I found a great teaching resource on youtube for GS carb operation.

https://www.youtube.com/watch?v=wyspAHrMbb8

Interesting? Yes.

Accurate? NO.

Please don't take that video as an accurate depiction of how your carbs work. In principle, it's not too bad, but ports are in the wrong places, the slide does not operate the way the video shows, many other details are just ... wrong.

.