View Full Version : Help...Pinging

11th April 2006, 01:51
Yes, I read jetting 101

I just put a Mikuni HSR 42 on. I was running WAY too rich with my CV. I changed the plugs and ran about 120 miles Sunday and here's what I found. Plugs are clean as a whistle...no marks or colorization at all. The metal still looks like metal, porcellin, too.

The bike really runs great with no backfiring or carbfarting. The only thing is a very slight ping when I do a WOT roll-on from about 3,000 rpm. It doesn't lug at all. It starts going strong for about 500 rpm and then just a few scattered pings the rest of the way up. It really hauls ass, though.

I haven't touched the out of the box settings except the idle. Does this sound like I should raise the needle or...?

If so, how the hell do you do that? I have bigger main jets that came with it and they're easier to change.


11th April 2006, 01:54
what kind of gas are ya using? an whats your max timing setting?

11th April 2006, 02:03
Stock ignition set "normal" and 94 octane Sunoco Ultimate

11th April 2006, 02:38
Sounds like the timing is a tad to advanced.

11th April 2006, 11:34
If the timing doesn't help and the pinging is only at wide open throttle you might try increasing the main jet one size.

11th April 2006, 12:29
I'd agree, might be just a tad lean at WOT.

11th April 2006, 13:07
I just did same mod ...my end settings are 1 size bigger on main jet.. needle, moved clip to raise 1 needle 1 notch ...runs great plugs look perfect but its only been in the 50's here I'm thinking I might have to lean it out once summer gets here . You might be spot on with your settings once it warms up ..hope this helps

p.s. they made a really good " mikuni sticky " I must have read it 20 times

11th April 2006, 13:22
Read that sticky alot, too. Basically, I'm waiting for my NRHS top end to get here. I'm worried that if I'm a bit lean now, with 94 octane gas and cold weather, when I go to 10.5:1, cams, and stage 2 heads, I'll be way too lean. Can't dyno it for 500 miles so I don't want to blow the whole thing up while I wait.

I figure I'll just richen up the main jet now (easy fix) and see. Looks like raising the needle is more work so I'll skip that until after my build.

11th April 2006, 14:30
I don't know SQUAT about Mikunis, and even LESS about the new ignitions, but I'd check your ignition settings with someone who knows first...that's what this sounds like...and ignition advance adjustment....

11th April 2006, 15:30
It's possible my timing isn't spot on, but I still don't want to be lean no matter what so I think I'll do the jet. I'll check the static timing, too, but don't have a way to do the dynamic timing.

12th April 2006, 02:53
sounds like voes is not getting vacume

12th April 2006, 12:48
The Mikuni install does have you "turn" your VOES 90 degrees. Not sure what that's all about, but I did it.

Believe me, though, the pings are scattered and intermittent. Plugs are super clean. I'm really trying to decide which to do...Raise the needle or go up 1 jet size.

12th April 2006, 13:12
Had same problem. Lean midrange. Went from the #97 needle to one size
richer, the #96. Bigger main affects 3/4 to full throttle.

12th April 2006, 13:16
You may need to adjust the VOES a little more. My pinging problem was alleviated after maximizing the jetting, retarding the timing and then finally adjusting the VOES. When you get to the VOES, just leave it hanging so you can reach it, test ride it and adjust it more if needed. You'll need a vacuum pump to figure out where you are at regarding "hg.

12th April 2006, 14:23
I'm not sure how you "Adjust" the VOES. Mine has 3 "Detents". if you're looking at it like a clock, they're at 3, 6,and 8 o'clock. Stock is at 3 o'clock and Mikuni has you rotate it to 6 o'clock (straight down). Other than going to the 8 o'clock position, how would you "Adjust" the VOES?

13th April 2006, 12:01
I adjusted mine about two years ago so lets see if I can remember. I'm not familiar with the description you just gave about 3, 6, and 8 o'clock but somebody else probably is. First thing, here is a good link to help you out

What I did was remove the bolt from the VOES and let it hang. I then dug out the silicone, exposing the adjustment screw. Take a vacuum pump, like a Mighty Vac and plug it in. Plug the other side with your finger. Squeeze the lever and look at your gauge on the pump. You will hear a definite click when you get to the current setting, from there turn clockwise and squeeze the vacuum lever again until you get it where you want. Ride it around, adjust until you get it where you want it. Replace the silicone and button it back up. Again, I'm not familiar with how you described yours so maybe its different on a 2000 model. Hope this helps.

13th April 2006, 14:03
Your plugs will not color much with today's fuel so it's not going to be helpful. If it doesn't ping at WOT steadily the main should be OK, I would suggest raising the needle either 1/2 step with a shim for that purpose or raise it 1 clip position. By the way, you raise the needle by placing the clip in the next lower position, there is a Mikuni American Corp website that will explain how to do it. But I would just try the needle change before any other changes.

13th April 2006, 17:01

That's what I was thinking. I'll give it a try. Thanks.

13th April 2006, 17:39
Raise the needle or replace with one richer. Although plugs will be cleaner with current fuels, you should still be seeing some discoloration to the porcelain. Yours sounds lean.

Don't need to mess with the VOES on a stage 1 1200.

2000 ignition is easy to adjust timing. I would set it to the factory specs, per your manual and then back it off by 2 degrees.

But first and foremost, richen the midrange.

Oh and talk to NRHS about their recommended Mikuni settings for the kit you are getting from them.

13th April 2006, 17:55
Just read the Mikuni tuning manual. It says to go with the 165 jet (comes with 160 installed) if you have Stage 1. 160 is for stock. This looks like a 5 minute fix so I'm going to do that first, and then think about raising the needle.

Oh, and shhhhh...didn't put the Daytona on yet ;)

16th May 2006, 01:17
Just read the Mikuni tuning manual. It says to go with the 165 jet (comes with 160 installed) if you have Stage 1. 160 is for stock. This looks like a 5 minute fix so I'm going to do that first, and then think about raising the needle.

Oh, and shhhhh...didn't put the Daytona on yet ;)

Did this do the trick, you get rid of your ping?