1980 GS450L Wont Start Help

[Dmpaul89]

New to the forum..

I just bought a nice little GS450L yesterday. I am having trouble getting it to start. THe bike sat for 10 years before I got it. Last night I cleaned the carbs (filthy) took the airbox out and cleaned the cobwebs off the bike. At first I had no spark, Dont know what I did but after messing with switches and wires for an hour It is Sparking! ok so i hooked jumper cables to the fram and ignition wires to try and start it, It turnes over good and is making spark, as well as getting fuel, but all I can get it to do is backfire. Before I put gas in the tank I put a little down each spark plug hole and it fired up and ran for 1 or 2 seconds. but now with the carbs clean It wont run at all. Also the plug wires were missing there boots so I just stuck a piece of fuel line over the wire going to each plug, Is this ok or do I need to buy boots for it to ever run? when it ran for a couple seconds I just had the plug wires sitting on top of the plugs. Any help would be greatly appreciated. Thanks

[pete]

Hey mate, welcome!

First off, post a g'day thread over in the GS Owners section so BassCliff can give you your mega welcome. There's a couple of manuals available on his site as well as many other things.

How thoroughly did you clean the carbs? Sounds like the pilot circuits may still have blockages and if you didn't remove the mixture screws (there is a cover over them) then they will be gummed up as well.

Best method is a proper soak for 24 hours in good carb dip, then rebuild with new O rings from www.cycleorings.com.

Also, valves out of adjustment will cause hard starting, so you'd be best of checking the valve clearances as well.

BassCliff's site has a carb rebuild guide on there by Flaming Chainsaws specifically for those carbs as well as valve adjustment stuff.

Here's his site:

http://members.dslextreme.com/users/bikecliff/

Edit: And we need pic's!

[Dmpaul89]

update

Thanks for the info PETE. I did not remove the caps on the carbs like you were talking about. I will try that as soon as I can. I put new spark plugs in last night and finally got it to start and stay running! But There are still problems.... First off after I ran it for 20 minutes I took the plugs back out to look at them, the right side looked nice and white, while left side plug was already black with carbon? when i had it running I felt both exhaust pipes and they were both hot. also It quit sparking again and I had to mess with the wires going to the coils to get it working. while messing with the coils I noticed that the left side one was warm to the touch while the right side was cool? IDK whats going on there. Ok so I can make it start easy now but if you give it a little gas it revs up and stays up most of the time it takes a while for it to go back down to idle speed, I checked the throttle cable and it is not bound up, What could be causing this? I guess I still need to take the caps off the carbs and clean those pilots you were talking about.... Also I have not installed an air filter yet, I was going to do away with the airbox and put pods on it. Thanks For your help.

[BassCliff]

Greetings and Salutations!!

Hi Mr. Dmpaul89,

It's a slow day at work so I'm actually reading sections I don't normally visit.

First of all, welcome. Second, SLOW DOWN! You need to perform all the proper maintenance on that bike before it will be safe and reliable. Hitting it with a hammer might get it to run but it will not be road worthy.

Read ALL of the information contained in the links below. Pay particular attention to the maintenance lists in the "mega-welcome". ALL of these items must be PROPERLY addressed in order for your machine to be happy. Treat your bike well and it will treat you well. If you skip any steps or take any shortcuts with this maintenance, you will be frustrated at best, seriously killed or injured at worst. Now let's get started.

If you are here you probably have a 30 year old motorcycle that needs about 20 years worth of maintenance. In the links below you'll find maintenance lists, documentation, wiring diagrams, "how to" guides, vendor links, tips, tricks, and a whole lot of GS goodness. This is your "mega-welcome". Let's get started.

Let me dump a TON of information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Cleanup Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. This is what NOT to do: Top 10 Newbie Mistakes. Now let me roll out the welcome mat for you...



Please Click Here For Your Mega-Welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

More links to helpful threads in the forum:
Help! Your Bike Won't Start
DON'T DO THESE THINGS
Help! Your Bike Won't Run Well
Oh God! Pods!


Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[mike10]

Thanks for the info PETE. I did not remove the caps on the carbs like you were talking about. I will try that as soon as I can. I put new spark plugs in last night and finally got it to start and stay running! But There are still problems.... First off after I ran it for 20 minutes I took the plugs back out to look at them, the right side looked nice and white, while left side plug was already black with carbon? when i had it running I felt both exhaust pipes and they were both hot. also It quit sparking again and I had to mess with the wires going to the coils to get it working. while messing with the coils I noticed that the left side one was warm to the touch while the right side was cool? IDK whats going on there. Ok so I can make it start easy now but if you give it a little gas it revs up and stays up most of the time it takes a while for it to go back down to idle speed, I checked the throttle cable and it is not bound up, What could be causing this? I guess I still need to take the caps off the carbs and clean those pilots you were talking about.... Also I have not installed an air filter yet, I was going to do away with the airbox and put pods on it. Thanks For your help.

If you have CV carbs it will never run right without the airfilter and all connections from the airbox to the engine tight with no airleaks. Airleaks are #1 for hanging RPMs Also you will have to rejet carbs if you use Pods. Fuel Air mix will not be right.

[pete]

Yup, what Mike said... classic symptoms of intake leaks and running lean as well (no air filter).

You will probably also find your carbs aren't balanced which is why one plug is white and the other black... also you want a nice tan colour on the plug, white typically means lean.

However, do as BassCliff says and get all that basic maintenance out of the way early on.

And if you leave the ignition turned on without the bike running for any period of time, it will typically result in one coil being turned "on" so it will get hot after a bit.

It's also crucial to get the charging system checked out. On these models, the ignitor can be susceptible to failure and it seems that overcharging from the typical dodgy charging system contributes to this if not causes it.

[Dmpaul89]

update

Thanks for the info guys,
I am headed up to st.louis motorcycle salvage to find a better gas tank and some other stuff. I have a question about the vaccuum carbs, since they need a filter to make them work properly will pod filters be restrictive enough? I am not putting them on in search of more horsepower i just like how simple and easy they are compared to the airbox which took me an hour to figure out how to manuever it out of the frame.... Seems like they built the bike around the air box lol.

[Steve]

I have a question about the vaccuum carbs, since they need a filter to make them work properly ...

Whoever told you that did not know what they are talking about.

They need to be re-jetted to handle the extra air that will be available, but you can run straight velocity stacks, with proper jetting.

Unfortunately, you do have one of the worst bikes for airbox wrestling. I have heard that, to get the airbox out in one piece, you have to remove the engine.

Just out of curiosity, why did you feel that you had to remove the airbox?

.

[Dmpaul89]

update

Steve, Thanks for your input. I removed the airbox because the bike sat so long that the foam filter had fallen apart and there was all kinds of crud inside, once i figued out how to posistion it it came right out. I did have to remove the battery tray and rear fender tho. so would the extra airflow with stock jets make the rpms "hang"? sometimes it wont go back to idle at all I have to kill it. other times it just takes a while for it to slow down. I still havent got the chance to re-clean my carbs, whitch may be the whoile problem. Thanks

[Dmpaul89]

Also a buddy of mine told me that I can just ream out the main jets with a torch tip cleaner to compensate for pods, Has anyone tried this?

[pete]

Firstly... yeah we all reckon Suzuki made the 450 frames around the airbox... that's why I have pods on mine too... as well as for general appearance reasons...

Some searching on jetting/tuning a 450 would've brought you here

http://thegsresources.com/_forum/sho...d.php?t=207055

Steve knows his stuff and yep, jet the carbs right and they will work with whatever intake/exhaust setup you have.

I wouldn't ream the stock jets out, keep them as a known quantity.

When working on my jetting, I bought a few different sizes and started experimenting.

Plug chops are the best way to understand your jetting situation and changes although I ended up with mine on a dyno.

Start with the main jets, then when they're right focus on the needle, then the pilot jets and mixture screws.

Your high RPM's are likely a combination of lean jetting (no filter) and old hardened rubber intake boots and intake boot O rings. I got new intake boots for about $US25 each and it made a world of difference.

[Dmpaul89]

update

Well I drilled out the caps that hide the mixture screws last night, One side was clean and the other had some white crust. shot some cleaner through the hole and put them back in at 2 1/2 turns out. Doesnt seem like there is much resistance in turning the screws maybe I should take the springs out and stretch them a little so they dont turn from vibration. Had another spark issue..... took every electrical connector apart that I could find an ended up being one that sits behind where the airbox used to be. ( bike has set for 19 years i found out ) I did notice something strange though, when I rock the on-off switch back and fourth the left cylinder sparks? huh.. also I havent been able to make the starter button work, Ive been jumping the solinoid. anyway by the time I got it sparking again it was too late to test out if the mixture screws made any difference. Will try later.

[Steve]

Sorry, but removing the mixture screws and squirting some cleaner down the hole is not going to do anything but waste some cleaner.

You will need to remove the carbs from the bike and do a full "strip and dip" cleaning. Not sure what you cleaned in your first post, where you said "THe bike sat for 10 years before I got it. Last night I cleaned the carbs (filthy) ...", but you can not clean the carbs properly that quickly, unless you splurged and got two cans of cleaner.

While you are kicking yourself for not doing the job properly the first time, look up cycleorings.com, order up a set of o-rings for the carbs, a pair of o-rings for the intake boots and the stainless bolts that hold the boots. Then follow the guide to clean the carbs that you will find on BassCliff's "little website". I think the one you want is the one written by "Flaming Chainsaws".

Since the bike will be down for a few days, why not take advantage of the time and adjust your valves, too?

With properly-set valve clearances and CLEAN carbs, your bike will start nearly instantly and run so much nicer.

.

[pete]

+1 to what Steve said, and the resistance turning the mixture screws is part due to the spring (they're fairly light) and part due to the O ring that's in there. New O rings will help that.

The left cylinder sparking doesn't surprise me... when you turn the ignition on, one of the coils will turn "on" due to the position of the signal generator rotor, so when you turn the ignition off the coil will discharge and the plug will spark.

[Dmpaul89]

update

well steve, when I sprayed cleaner into the hole that the screw came out of, it went through and came out the back of the carbs (where the aircleaner goes) so this told me that the passage was not blocked. As far as when I cleaned the carbs the other day, I did not know at the time that there were hidden screws behind caps.
So I figured I would go ahead and do it while they were on the bike then test it and go from there before i just rip the carbs back off before even knowing if that is needed.
sure If the carbs need cleaned again I will do it, but I have limited time to work on toys