Popping at WOT (video attached)

Luigi Garzone /

V1 polini, case matched, VM20 with 160 main jet (started at 145 and upjetted trying to help fix problem) + sidebleed estoril

If I hold 3/4 throttle or go straight to WOT I start getting popping noises from the top end that sounds like detonation. The bike cuts out and bucks when this happens.

I'm running stock points at 18° btdc. Since jetting changes haven't helped I'm thinking I have to bite the bullet and get a CDI with a curve.

Do you think this is a timing issue? Happens within a minute of starting the bike so I don't think I'm overheating this quickly

Re: Popping at WOT (video attached)

Ľ̷̝̽͒i̶̛̼͑͠ȁ̸̧̛̽m̵̻̟̯̀̅ ̷͎̙̽̊F̶̲̺͑̓ F /

What gas are you running? pre detonation could happen when your hot at WOT if its lower quality gas

Re: Popping at WOT (video attached)

Barack Obama /

Upjet and put some fucking jeans on

Re: Popping at WOT (video attached)

condenser, and service your points too.

Re: Popping at WOT (video attached)

That seems like some violent action. I’ve had a bike ping a little from being lean at WOT and mid rpms. Sounded like clicking.

What spark plug do you have?

Re: Popping at WOT (video attached)

Dirty30 Dillon /

That is definitely pre-det. I would stop riding it and pull the head before you pop a hole in the piston.

More than likely I am going to guess an airleak somewhere, combine with too advanced timing. try at 16-15* BTDC as that will push more heat into your pipe.

Re: Popping at WOT (video attached)

🇮🇹💦 Of the Loin /

I've definitely experienced this with that rural Midwest gasoline

I don't remember degrees or numbers of timing in V1s because the stock timing works pretty good for everything (not great, but pretty good!)

Do the timing mark on the flywheel and the timing mark on the case line up?

Holding 3/4 OR WOT causing this points to it not likely to be a jetting issue.

I'd clean your grounds and replace your taillight bulb

Re: Popping at WOT (video attached)

Luigi Garzone /

wired in an external condenser from my 74 beetle today. Bike runs great. Thanks for the suggestions

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account