GS450 Engine only starts cold with choke out + 3 min warm up

[gs450dave]

G'day,

I'm a new rider who's just bought a 1980 GS450.
The engine only starts with the Choke out, adjusting it so the bike revs above 1000 revs, occassionally giving it a bit of throtle. After a period of about 3 minutes I can push the choke in and the engine continues to run.
After the carby is warm I can restart it without the choke, at first it struggles to start on its own.
WARNING: The following may be a silly question:
Is this start-up procedure the expected behaviour for an older bike, or is there something I can fix to improve this?
The temperatures of my garage in sydney would be about 12 degrees celcius (not extremely cold weather).
Please respond if you have any info.
Many Thanks,

gs450dave.

[Anonymous]

hey mate!
I bought a GS550 1980 this year - new rider too. My start up is just about the same as yours. When the bike is warm it kicks right over. But in the morning it will grind for quite a while before it goes. One thing that works for me is to give the throttle two good twists before I try to start it - yes, with the choke full on as well. I also disconnected the switch on the clutch lever so I can have two hands free, one on the throttle and one on the start button.

[snark]

Not a silly question...I had the same, exact problem with my bike. If you haven't already; think about changing the Carb Boot O-rings. You probably have a small air leak from the rings flattening out over time. The heat of the engine makes the rings swell and fill the gap after a few minutes. The bike normally should take about 1 minute to warm up with the choke at about 70 F. After that you should be able to take it off choke and drive away. Search the forum for topics on Carb Boots and you will find a lot of how-to help. Good choice of a bike...they are easy to ride and easy to work on. I have a factory manual for this bike and have done this job before. Don't be afraid to ask questions.

[gs450dave]

Thanks for that ericp and snark,

I'll try both things out when I get home.
I've just ordered a Suzuki GS/GSX250, 400 & 450 Twins 1979 - 1985 Repair Manual.
I'm hoping this will show me how to change the O rings, as you have suggested Snark.
I have seen a post about a which changes the revs the bike does when idling, I don't know if its related.
I'll also look for any info on Carb Boots.
Many Thanks,

gs450Dave

[snark]

When it comes to manuals, make sure you get the Clymer Manual. It seems to be the most useful. Ask any questions you may have and I'll try to help.

[chrissinc]

You're fine, totally normal for a bike to need choke in cooler weather(12 C). During the hottest months of the summer you should be able to not use choke on a cold engine but have to use a little throttle to keep it from dying untill fully warmed up. Welcome to the forums!

[gs450dave]

Thanks for your replies and warm welcome,

This morning I tried pushing out the choke, turning the throtle whilst off a few times, and then starting it.
My Bike would not start!
-I think I might have flooded the engine.
-A friend of mine has suggested it might be the battery, although the headlights, indicators and high beam are working fine.
-In the begining I could hear it trying to start. But towards the end I could only hear a click.
I have hardly spent any time with my bike yet. I don't ride to work yet. But I thought I'd post this in, just in case I can diagnose it before I get home.
BTW snark, before I could see your reply I ordered the Heynes manual (not the clymer one), I haven't recieved it yet but I hope it will be just as good.

Many Thanks,

gs450dave.

GS 450 E, 1980, 44,500 kms.

[redliner1973]

Turning the throttle does absolutely nothing to help start. There are no accelerator pumps like a carbed automobile. Leave the throttle alone, pull out choke, crank her, she should start, once started, vary choke as needed to allow engine to run at lowest rpm without dying. If she does not start this way, there is other problems with it.

[gspaul]

Never use the throttle on a cold start, choke only or it will flood!

[gs450dave]

I am still unable to start my Bike.

The starter button seems like its working.
Initially the Bike makes the starting noises, but then all you hear is a click.
The horn, lights and blinkers all work.
Does it sound like the Battery?
I'm gonna check the battery electrolyte level.
Thanks,

gs450dave

GS 450 E, 1980, 44,500 kms.

[gspaul]

Hey Dave, if you have enough power in the battery to start here is a simple check for the starter relay.(solenoide)
Get a screwdriver and short the two contact point's on it,if it start's your relay is done, the good news is any 12v relay will do the job.
If not clean the surface on the starter motor that the brushes come in to contact with ,useing very fine wet and dry.
The rule's in order,
The battery is stuffed,
The relay is stuffed,
the starter is stuffed,
Try jumping from a car battery,NO CAR ENGINE RUNNING!

[gspaul]

Get back to me when you think you know what the prob is!

[Anonymous]

i have a 1981 gs 450l that had the same type of problems..heres what I did...i purchased used intake boots from ss 2 wheel and put new o-rings in(you can check to see if you have a leak in your existing boots by spraying carb cleaner on the boots....the engine will rev. up immediately) I made sure that I had the airbox sealed also...I checked fuel line for leaks and checked the vacuum line for cracks around the ends....bike started right up.... hope that helps.

[gs450dave]

An Update,

I did the starter relay test and the bike did not start, moreover I think it drained more juice from the battery, so it was starting to look like the battery.
Anyway I don't have any gear yet so I called a Road Side Assitant.

It was definitely the battery, I got a jump start and it worked first go (BTW I don't even have jumper leads so I couldn't try this myself).
However he did some voltage tests on the electrical components behind the left side panel, and concluded:

- The charging system of the Bike was faulty as he got a variety of vaultage readings running through the Bike.
- He also said the Battery will not necessarily recharge if I leave it running.
- And I will need to have a look at the recharging system.

Does this sound like a correct diagnosys?
How expensive is the charging system to replace, or is it made up of a number of components wires?

I'm going to start a new thread with these questions?

Thanks Fellow Bikies,

gs450dave

[gspaul]

He could be right Dave, but first clean every connection and earth in the chargeing system.
If that does not help consult the "stator page's" on this site and it will take you on a step by step test.
Good luck!