1987 GS 450L Igniter Problems

[Guest]

First time posting so hello everyone, I just bought my first bike and have been working on it to get everything going. Well now when I start the bike it idles fine but if I hit the throttle as soon as it approaches 2k rpm it starts to sputter and can't maintain a high rpm. The engine will just keep going up and down on rpms unless it is in idle. My father in law who worked on numerous motorcycles told me it is a Igniter problem but I can't find a replacement for 100$ or less. If you guys know of any aftermarket igniters or a different igniter that would work with this bike that would be awesome!

Again Hello, and thank you for any kind of direction on where to go from here.

Also I said it in the title but not the post. My bike is a 1987 GS 450L

[Big Rich]

I can't say whether that is a bad ignitor or not, so wait for others to chime in. For a cheaper ignitor, look at ones from an early GS500. The timing curve is a little different (along with the wiring harness) but it should work otherwise.

[posplayr]

I would suspect carburetion specifically plug pilots or leaking manifolds before declaring the ignitor was going out. Generally if it is firing it is firing and would not be intermittent.

Do you get blue sparks on all 4 plugs?

[trtsmb]

The 450 only has 2 spark plugs .

[trtsmb]

Have you cleaned the carburetors yet? Carburetors can be behind a lot of the problems on the 450.

[posplayr]

The 450 only has 2 spark plugs .

Gee I hope op is not still looking for those other two plugs.

[Pangolin]

Lol I have checked the plugs and they spark okay, replacing them today though, also we cleaned the carbs out 3 times. Taking everything out and checking for any obstructions. This bike was sitting for 13 years before I got a hold of it so there was a lot of varnish every where and needed a lot of cleaning up

[posplayr]

Lol I have checked the plugs and they spark okay, replacing them today though, also we cleaned the carbs out 3 times. Taking everything out and checking for any obstructions. This bike was sitting for 13 years before I got a hold of it so there was a lot of varnish every where and needed a lot of cleaning up

So now that you know why the extra two plugs are not firing, do you still think you have an ignitor problem? We already guessed you had varnish problems?

[Pangolin]

I am 80% sure it's igniter problems. The carb looks almost brand new from how much we cleaned it. The engine is good. Everything works on the bike except for the the engine not being able to keep rpms steady out of idle. Another little bit of information is when I rode it the other day to see how it acts at higher gears, it would seem like the electrical would just kick on for a little bit and would be an awesome ride then just go back to bouncing rpms and sputtering.

[posplayr]

I am 80% sure it's igniter problems. The carb looks almost brand new from how much we cleaned it. The engine is good. Everything works on the bike except for the the engine not being able to keep rpms steady out of idle. Another little bit of information is when I rode it the other day to see how it acts at higher gears, it would seem like the electrical would just kick on for a little bit and would be an awesome ride then just go back to bouncing rpms and sputtering.

You are assuming it is electrical because you cleaned the carbs? Not a good assumption.

Did you soak them as recommended. You have to make sure all the ports are clean. Plugged Pilot jets will act the same way. If they were real gummed up run a piece of copper wire through to make sure they are clean.

[Pangolin]

I'll check the carbs again here within the next few days, see if I can find a problem with them. I have done the copper wire through the jets since I found those to be entierly clogged and checked everything else on the carbs for blockage. Couldn't find any obstructions after cleaning them again

[posplayr]

I'll check the carbs again here within the next few days, see if I can find a problem with them. I have done the copper wire through the jets since I found those to be entierly clogged and checked everything else on the carbs for blockage. Couldn't find any obstructions after cleaning them again

Have you checked for air leaks? Use a little carb cleaner around the manifolds.

Do you have full voltage to the coils and ignitor?

Have you done a Quick test? If you are going to chase electrical you need to start there.