1980 GS450E wont start

[Guest]

Hmmm I'm a bit stumped at the moment, everything sounds in order...

You did say the airbox is all sealed up now right? Pretty sure you did...

Have you given it some choke maybe?

A valve adjustment certainly can't hurt so worthwhile knocking that off regardless... and you never know it might help!

 

[CycloneGS]

My top lid has a crack in it. would that cause it?

 

[Guest]

Put some duct tape over it as a temporary fix to see if it helps...

 

[CycloneGS]

Duct tape didnt help.

 

[Guest]

Bugger! Man I'm reaching the end of my limited knowledge here...

I might be rehashing stuff but I gotta list this stuff out otherwise I'll go nuts thinking about it more...

- Got good spark?
- Got clean carbs?
- Got fuel tap on prime?
- Got fuel leaving the fuel tap?
- Got fuel in the float bowls?
- Got an oiled air filter?
- Got a sealed air box?
- Got kill switch on run?
- Got clutch in or clutch switch bypassed?
- Got vacuum and fuel hoses the right way around? (I don't think they fit the wrong but I'd best raise it in case)

I can't think of anything else right now... I'm really hoping someone more experienced can chip in here!

 

[CycloneGS]

Yep, everything checks out. I took it to the shop to see what the deal is. There is a super cool vintage bike shop here in town. Pre 1982 bikes only...http://vintagecycledsm.blogspot.com/

 

[Guest]

Interesting... I hope they do a good job! Normally I'd be saying don't take it to a shop, but in this case it looks like it might not be a bad idea...

Don't be surprised if it's something really obvious though...

 

[CycloneGS]

Yeah, this will be humbling

I hope its not something major, I only paid $150 for the bike.

 

[Guest]

True, definitely let us know what they find though...

 

[Flaming Chainsaws]

I was going to say check the cam timing then do a valve adjustment. If the valves are out of adjustment, the bike will be hard to start.

And since you have, fuel, spark, etc, it would make sense to me.

Hope the shop does a good job!

 

[Guest]

Did you check compression?

 

[Guest]

Good call Chef! I knew there was something I was missing...

 

[CycloneGS]

I dont have a tool to measure compression, but just plugging the hole with my finger I had some decent pressure. Still waiting to hear back from the shop tho.

 

[apopleptic]

I have the same bike, although mine doesn't look quite as shiny as yours, and I had some similar issues in getting it started.
I also had to replace my plugs and igniter, but it still souldn't start/run correctly.
I ended up having to fully clean the plugs and then regapped them (manual said .024-.028" the shop insisted .032in), the moment I adjusted the gap to .032in I could tell the bike was about to start, but it still wouldn't run right but it would try to start. turned out to be a combo, #1 the spark plug gap had a speck of something conductive inside the barrel so the spark wasn't happening in the gap, #2 I had routed the throttle cable wrong so it was always giving it more gas than appropriate and it would alternately flood/rev.

 

[CycloneGS]

Apopleptic, yeah sounds similar to mine.

Shop told me that my spark advancer was broken. I trust these guys for sure, but I dont know what that part is? Does he mean the signal generator?

Anywho, school is crazy busy right now, its a good thing the twin is in the shop.

 

[Guest]

If he's talking about the advance mechanism, it's the bit the rotates on the end of the crankshaft and has the rotor attached that sits between the signal generator sensors to trigger them.

If you take your signal generator off, you'll see the rotor is mounted on a plate that has two weights and springs on it and that's the advance mechanism.

To my way of thinking, if that was "broken", then it simply wouldn't advance the timing correctly, but it should still start... I could be wrong though...



Second picture is the plate with the weights and springs removed.

 

[apopleptic]

I looked into that part that Pete had referenced (signal generator I think) and it was easy to test with an ohm meter,
The part that failed in relation to this was actually the igniter which was quoted to me at $350. I laughed and then called a junk yard and they pulled and shipped me a working igniter for like $40. I have to tell you, it was very frustrating for a newb like me. Luckily there are alot of helpful people here.

 

[CycloneGS]

Yeah, I tested the generator and it was good. I replaced the ignitor and then I had spark. I was out of ideas. so I took it to them.

 

[CycloneGS]

So the metal part that spins inside the signal generator, that was broken! The manual said nothing about it and I could have never found that. Anywho, 170 bucks later my motorcycle is ripping up the streets of DSM... All my buddies with Honda 350F's are jealous

 

[Guest]

So the metal part that spins inside the signal generator, that was broken! The manual said nothing about it and I could have never found that. Anywho, 170 bucks later my motorcycle is ripping up the streets of DSM... All my buddies with Honda 350F's are jealous

Wow ok! Glad you got it fixed! You can't buy them separately as OEM either, you have to buy the whole advance plate by the looks and according to the fiche it's actually discontinued, so well done to the mechanic for getting it sorted. $170 probably isn't a bad price depending what they did...

Very glad to hear you're up and running and beating Honduh's