1983 GS450L Won't Run just backfires!

[willis1345]

Got this 1983 GS450L for project, who knows how long it sat but I got it to run only with choke on. Notice was only running on one cyl. so did complete carbs cleaning which were in bad shape. I jumped the gun and put pods on carbs and put some straight pipes on it. Well now it won't start and after awhile of turning over it backfires hard. Have an old Clymers service manual and tried checking things, it has spark to both plugs but not sure how strong of spark, tried checking signal gen. and igniter but not conclusive. I know my way around bikes (mostly Harleys) but this has me stumped. Is it Fuel or Electrical, need some direction on where to look.

[rampimpin]

well first off pods cause more aorflow into the carbs throwing of the air fuel mixture its getting way to much air and not enough fuel.
if you run pods you will have to rejet to compinsate for the imbalance and the combination of the exausr and pods will really cause problems.

my suggestion is if you have it put the stock airbox back on not really sure on the exaust but ive made the mistake myself it never turned out very well

[BentRod]

back to basics

Assuming the airbox, air filter, and stock pipes are still in decent shape, and you have them, get them back on there. right now you don't even have a base line to start from, so you don't know why it would only run with the choke on. For all we know, it could be a damaged diaphram in the petcock, an air leak in the carb boot, or anything in between.

Putting that aside, pods and pipes means you need new main jets, pilots, new needles. You have an 83, so I assume you have the newer carbs. (BS32? BS34?) so you are in luck, there is a kit for that -->search it in the forums, pods pipes panic.


The possible causes are way too long to list. Going to need a lot more information... I can tell you poor sparking isn't going to give you a back fire. But keep checking everything, from the caim chain/cam alignment to the resistance in the electrical system.

Also, and this is a personal touch, I usually trouble shoot with high octane, Marine gas. It is really not at all needed, but it does eliminate problems like water in the fuel, or any scratches or points in the cylinder.

[BentRod]

Straight pipes are for ass holes on Herdleys. Get a muffler.

not helpful... leave the guy alone. You should be ashamed.


By the way

It's a 450. Even with no pipes it is still well under the legal noise limits in almost all states and most cities.

[tkent02]

not helpful... leave the guy alone. You should be ashamed.


By the way

It's a 450. Even with no pipes it is still well under the legal noise limits in almost all states and most cities.

It's just as loud as a 900cc four cylinder. And t's probably the reason it won't run.

[Mr. Sinister]

To detail how sensitive to airflow changes these bikes are, my 450 didn't have an air filter in it when I got it. It wouldn't rev past 5-6k, and was way down on power. I fabbed a makeshift filter for the time being, but it now pulls hard to redline.
So you're pulling in more air, and flowing out more air. You NEED more fuel. With no jet changes, your motor is running dangerously lean. Lean enough to torch a piston. The BEST thing to do would be to put it back to stock, and get it running right. Then add your pods and change your exhaust, and do your carb work to compensate. There's no set formula, you're just going to have to tinker until you get it right.

[willis1345]

Straight pipes are for ass holes on Herdleys. Get a muffler.

First time on this forum and some dillweed calls me an *******. Well I did get some good advice from others, thanks alot. And for tkent I think you know where to put that muffler!

[barnbiketom]

put the mufflers on
put on the airbox

RIDE IT

[chef1366]

Take off the pods and duct tape up half of the exhaust side of the carbs without covering any air jets.
When it starts up and runs you'll see you need to jet for the extra air flow.

[willis1345]

I'm going to stay on this site because of all the good advice outways the one guy (tkent) that has no class and for all I know doesn't know anything anyway. I can't say on here what i would like to say or do to him.
Back to the bike actually am glad to hear it's where you all have been pointing, I was afraid it was that but i see all these pics of people running pods and straight pipes. will regroup and try what you all have suggested, except for tkent, Southpark - no wonder you are f#!&*$ up.

[RichDesmond]

Keep in mind that it's possible that the carbs aren't as clean as you think they are. The internal passages can get so gunked up that they're almost impossible to get completely clear, and sometimes it's hard to determine that.
Put the stock stuff back on, and if it's still not running right get back into the carbs. Vacuum leaks cause similar symptoms too.

[willis1345]

I apologize for my comments. I was out of line and should have known better than to let that get to me. Gettin too old for that life is too short. Back to bike only comments and posts. This was my very first attempt at forums. Will be good.

[chef1366]

tkent is a good guy
Very sarcastic and always looking to push buttons. You must have a big red one on your chest.

[1_v8_merc]

Just ignore the Naysayers...it's your bike, bottom line.

But yeah, if you have no idea about bikes, you need to put stock junk back on.
You absolutely Will hole a piston, if you're too lean.(just ask my 550)
------------
Back on subject: If you're popping, or carbs are popping, it's too lean.
You need bigger main jets, needles(on slide) need to be done, and float height needs to be raised- to allow more fuel.