98 Valkyrie Miss under load

[Walkyrie]

I have a 98 Valkyrie that has always run like a million bucks. Yesterday it started to miss when in gear (load) like it would sound if it was running out of gas. It rev's just fine in neutral. Any ideas what might have changed, literally over night. Bike has approx. 17K miles.

[R J]

My 1st guess on what little infor you provided would be a clogged main jet.

Run a good can of cleaner through it.

Add the cleaner, take it out and run it up into the higher R's so as to get the solution into the main jets.

Bring it home and let it set overnight.

Next day take it out and run it some more in the high R's.

Repeat the let it set overnight.

3rd run, go ahead and run the tank out and run it in high R's even if ya have to run it in 3rd gear.

Fill it up, add another can of solution, your choice, I'll be cursed if I'll make suggestions anymore.

Don't appreciate being told I don't know what the F I'm talking about.

I'd say I been wrenching more years than some of the know it all's are old.

I'll get off my soap box now.

[Willow]

Does it sound to anyone else like a vacuum leak?

[R J]

Does it sound to anyone else like a vacuum leak?

Carl, if it was a vacuum leak, it would do it all the time.

Since he says it is in the higher RPM's, that tells me it is going into the main jets and that is when it appears.

It could possibly be a broken carb spring, but I'd rather not suggest that.    Broken carb springs don't act that way, 99% of the time.

However, it wouldn't take very long to have a look see and eliminate that one.

[Willow]

R J, I reread what he said.  I didn't see anything that referred to higher revs.  Under load means different things to different folks.

If you disregard your interpretation of higher revs does it sound like a vacuum leak that he notices when he needs the throttle but isn't significant when in neutral?  Dry and cracked tube or plug?  Overnight, low mileage seems consistent.

[R J]

R J, I reread what he said.  I didn't see anything that referred to higher revs.  Under load means different things to different folks.

If you disregard your interpretation of higher revs does it sound like a vacuum leak that he notices when he needs the throttle but isn't significant when in neutral?  Dry and cracked tube or plug?  Overnight, low mileage seems consistent.

It doesn't take that long to check the hoses.

If he has the time and wants to do that, then go for it, if nothing found, he has just eliminated another possibility.

[Patrick]

Since the problem reared its ugly head only when under load, I was going to suggest a possible bad petcock [ if OEM style]. But, I'm not going to. 

[Ricky-D]

Miss under load.

Bad spark plugs should be the first suspicion.

But of course, any modifications to the carburetors

can result in the same symptoms.

[Attic Rat]

Not much info to go on but if the miss occurs below 3,000 RPM and goes away above 3,000 RPM then I would take a look at the slow jet.
Oh by the way Willow is right RJ about the add not saying anything about the high RPM's are you starting to get old and reading things wrong LOL LOL LOL

[R J]

Not much info to go on but if the miss occurs below 3,000 RPM and goes away above 3,000 RPM then I would take a look at the slow jet.
Oh by the way Willow is right RJ about the add not saying anything about the high RPM's are you starting to get old and reading things wrong LOL LOL LOL

Give me a break Attic Rat, I sliding into 82 years old and my eyes aren't as good as they used to be.    Even with glasses on.

Hey Bro, ya'll have a good day.

[signart]

A miss doesn't sound to me like fuel related, more like a cylinder misfiring. More like a spark plug as mentioned, or vacuum related possibly. If it is cutting out, then look at fuel related and everything else.

[BF]

Not much info to go on but if the miss occurs below 3,000 RPM and goes away above 3,000 RPM then I would take a look at the slow jet.
Oh by the way Willow is right RJ about the add not saying anything about the high RPM's are you starting to get old and reading things wrong LOL LOL LOL

Give me a break Attic Rat, I sliding into 82 years old and my eyes aren't as good as they used to be.    Even with glasses on.

Hey Bro, ya'll have a good day.

Bless you sir. 

I hope to make it to 82 some day...but right now I'm doing good to make it to 61. 

[Attic Rat]

ok RJ I will give you a break just because you are a great guy. I was just having fun with you. Take care my friend

[Walkyrie]

It turned out to be a fouled plug. Bike sat in 2013 because my hip was so painful I couldn't ride, gas in carbs went to hell and promptly fouled once in use. The good news is a cheap fix and back to normal.