Another high speed/rpm power loss - stumble

Hello all, it's been a while since I posted but hope you are all enjoying your Grisos. First off, Beetle, I have not forgotten about you, your map for the stock exhaust worked wonders for the bike and I will be getting the donation out to you. Very sorry for the prolonged delay and hope you are feeling much better. I was very sorry to hear about your accident!

Ok, so I took the bike out a few days ago and had her up to 120mph no issues. I rarely get her up in this range but every now and then it helps to remove cobwebs from the brain. Anyway, just prior to this I removed the air box and secured the stock filter with Todd's ring. Took the bike out again and ran it back up over 6000k and noticed a very brief hickup in the power. Everything seemed to be perfect up to approx. that rpm. Didn't think much of it at the time as it was over in the bat of an eye and I brought her back down under 6000k pretty quick.

Today, just for shits n giggles I installed a Sprint high flow filter (PO8 - PMO1S) with no airbox to see how it would affect things. I will be installing a new slip on aftermarket pipe from MASS (M1 double carbon) shortly but am currently still running the stock pipe. Again, she ran beautifully with no surging or loss of power all the way up to approx. 6000k at which point she stumbled and lost power a few times. I have not experienced that with the stock filter when I would run it up in the past but am not a mechanic and have no idea if the two could be related. Anyway, I will swap out the high flow for the stock filter tomorrow and give it another go. My only concern is will this cause any damage even if I keep it under 6000k?

I have read the thread and posts re. a similar issue by MotoMT and Bulldog9 from a few years back fwiw.

Any thoughts would be appreciated.

Don't worry about the donation, mate. That's ancient history.

I implore you to put the stock filter back in, and restore the airbox lid. Leave the snorkel off.

Regardless whether the surging is caused by an extreme lean condition (which is quite likely), the removal of the lid and addition of the rock strainer filter will be causing a very lean condition overall. The 5AM ECU has no way to compensate for the extra air, and without a full remap, it will be running too lean. I recommend that if you intend to keep the open airbox, please get the bike remapped to suit.

Will get the stock filter back in with air box sans snorkel prior to heading out tomorrow Beetle. Thanks much for the quick reply!

Running the bike back up to 6k-7k with the stock filter, airbox and no snorkel has seemingly done the trick beetle. No issue like what was experienced yesterday.

Quite a relief. Thought it might be something more serious. Thanks again!!

Good job. The advantage of running without the snorkel is a slight increase in mid range torque. That's a good thing, and costs nothing.