84 carbs & etc.

[Dano]

Need a little help. Changed left rear exhaust donut, got it back together, checked plugs, all tan on porcelain. Has been sputtering at idle, pulled off the breather, upon rev up and back down, am getting a backfire (fuel, no fire) from the left rear cylinder. Doesn't do it constantly, only once per blip. Pulled plug wires one at a time, LR doesn't make much change, LF is definate miss, RF is questionable, same as rear. Doesn't seem to affect operation, pulls good with a good twist of the right wrist, even with rider on back. Doesn't seem like a clean burn out of the exhaust, either. It just feels like it is missing. Oh, also have gas on under side of breather box on left side, can't find source. Not dripping, just coated. 1 more thing, changed stator and regulator, is 14.6 at the battery too high? I have a couple spare regs to try. Help is appreciated. Will be back shortly, going back into garage to put plastic back on. Thanks in advance,

Dan

[Venturous Randy]

Is your carbs in sync?

Backfiring with the breather off is not real uncommon. Some don't even want to run with the breather off.

RandyA

[Dano]

Haven't done that yet, next door neighbor is an at-home bike mechanic, just waitin to get to him.

[bongobobny]

Although I haven't checked mine, 14.6 volts is a normal voltage for charging in most automotive charging systems. To adequately charge, you want to be over 12 volts...

[Yammer Dan]

Plug wires and Caps??

[Dano]

That's my next move, I believe. Whats the best place to purchase, web or dealer?

[Yammer Dan]

I got metal wires from Parker Yamaha and ends from Buckeye. Both on line. Dealer will tripple price a couple of times.

[GeorgeS]

I have the Electrix stator, and replaced R/R once. Mine runs 13.7 Volts at the battery, 2000 + rpm. I have never seen over this.

 

I would consider anything over 14 V to be on the high side. ( You might be cooking your battery )

 

Question: is your battery water level going low, sooner then would be expected ??

 

If you are running a Sealed Lead Acid Battery, I would shine a bright light thru the case, and try to see if the water level is over the plates.

 

You might check the connector pins on your TCI, maby dirty connectors.

 

also check for High resistance across the " ON OFF " Contacts of the Ignition Switch.

( should be zero ohms )

 

Check your 40 AMP, main fuse, open it up and check the two small #1 phillips screws that hold the fuse element in place. ( They do come loose ) Any excess resistance across the fuse, or across the On Off contacts, will lower the voltage to the Ignition Coil Primary windings.

This will affect Strength of plug fire

 

Check your " Run Stop " switch, for dirty contacts.

[Dano]

Thanks George, being a master electrician, I should have done all that, but with remodeling the kitchen, etc., the brain and me don't get enuff time to work on the bike as much as I want to. Will try that when I get a chance.