No start problem

[CrazyHorse]

Over the winter have been starting my 1st gen once a week battery is on charger. Cranks fine, up on center stand gets spark to all cylinders it just will not start bike is in Neutral, full of fuel with Stabil fuel is filter is a few months old. I did manage to break my throttle cable though. Have sprayed starting fluid in still wont fire. If starting fluid cant get it to fire I dont know what will.Im confused since I have spark. Any ideas?

[BuddyRich]

You have spark to the plugs but are the plugs firing? Is it possible the plugs are fouled. I would probably start there. If you not getting any type of backfiring then its not timing its just not lighting the fuel.

[CrazyHorse]

Ill check it out Thanks

[Squeeze]

Fuelpump is ticking, if you turn the Key ?

[Yammer Dan]

Buddy is right these things like plugs. Also check that fuel pump. I did that not long ago because I unhooked the ground to the fuel pump and couldn't figure out why it wouldn't run.

[CrazyHorse]

Fuel pump ticks sounds a little different then it use too. Plugs look great.

[BuddyRich]

Next thing to try is a little fuel poured down the throats. Just a little and try to fire it up.

[CrazyHorse]

I disconnected the fuel line and turned the ignition on fuel did not pump out. Bad ground or fuel pump maybe?

[BuddyRich]

Or fuel filter

[CrazyHorse]

Disreguard last I'm an idiot forgot to turn on run button fuel pumps fine. Sprayed starting fluid did not ignite but I have spark at the plugs Im lost

[BuddyRich]

What I would do.. Pour a little fuel down the throats. If no backfiring or even acting like it wants to start I would replace the plugs. This hurts if done wrong but pull a plug and put the wire on it. Now hold the plug so its grounded and turn the engine over. You should get a good spark at the gap. I would also try a different plug than the last one you checked.

[CrazyHorse]

The spark is bluish/yellowish.

[Yammer Dan]

Good fuel??

[BuddyRich]

Did you fix the throttle cable yet? I would pour a little fuel down the throats or try to choke it. Sounds like you got good spark.

[CrazyHorse]

No Im just pulling it by hand. Poured fuel in nothing. Starter fluid nothing Fuel pump pumps fuel. Timing? CDI? I do have the airbox cover off is this gonna mess it up with too much air. I figure with start fluid it should still fire.

[BuddyRich]

Your getting spark so something should ignite. I don't trust starting fluid.

Try putting the cover back on and choke then un choke it. Does the throttle cable run to the cruise control? Do you see the sliders operate when pulling on the cable? I'm lost too at this point. Gas and Spark usually result in fire

[AZSpyder]

Fuel, spark and compresson will at least get some sort of fire. I don't know if these things ever pop a cam chain or experiance some other sort of silly failure. Maybe its worth a compression check.

Jerry

[Guest bigtruck]

when i was doing my battery cable upgrade,i tried to start it with the airbox off.I got it going after a lot of trying.It didn't want to start.And when it did,it ran like crap.Than ran fine with the airbox back on.The airbox makes a difference in the fuel to air ratio.

[Black Owl]

From the for what it's worth department....

 

If it were I, I would try a set of new spark plugs. It may simply be a case of weak ignition spark under compression.

[Marcarl]

Question: Where are you putting, pouring the starting fluid.

Is it a spray starting fluid and is it eyther

if you take out a plug is it wet or dry

If all else fails, try something stupid, such as: Get on the scoot, put up kick stand, squezze the clutch, check the emergency shut off, turn the key, wait for fuel pump to stop, choke a little, and turn it over. Don't laugh I seen it work, in my own shop.

Other thing that comes to mind is that I would replace the cable before I'd get to any really serious stuff, you just might find your answer in that process.

[hipshot]

i am not an authority on yamahas, by any means, but from what you are describing, your "stop/run" switch might be faulty!

just jt

[Yammer Dan]

I'm with Black Owl on this one. They will fire fine outside the engine but are dead under compression.

[RSTD-MN]

I have a couple thoughts on this thread.

 

I would make sure the battery is fully charged, so as not to be cranking too slow.

 

I would remove all the plugs and verify they are all dry, hoping to see some wettness on them to ensure fuel is getting to them. I use starting fluid to dry them out, depending on your outside temp will determine how long it will take for them to dry, air psi works well to clean them off and have even lit them on fire away from anything flamable.

 

If when you have inspected the plugs they were soaked with fuel, I would consider putting a small amount of engine oil down each cylinder and cranking the engine over without plugs in. It is possible you might have flooded each cylinder excessively to the point of washing the cylinder walls and lowering the compression to the point it will not start. Oil will increase your compression. I would also add if this in fact was the case of excessive flooding, I would change the engine oil once you have gotten it running.

 

you are pulling on the throttle cable, I have seen in the past a few of my bikes that would not start if I gave it any throttle. Full choke only.

 

Hope it works out for you,

David

[Venturous Randy]

you are pulling on the throttle cable, I have seen in the past a few of my bikes that would not start if I gave it any throttle. Full choke only.

 

Hope it works out for you,

David

 

This is a good point David made. My 83 is one of those bikes that does want to start if you give it much, or in some cases, any throttle. Especially when the system is somewhat compromised to some extent, like with a fouled plug or something.

RandyA

[Yammer Dan]

Mine is another one. Full choke to start. Backing off as it warms up.

I'm still going with dead plugs underv compression. And check that kill switch. Remember hearing of someone that spent three hours in front of a bunch of people before finding that!! Wouldn't know who...