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Hayabusa momentary power cut at high RPM
Perpetrator - 10/7/18 at 09:14 PM

As title, once warmed my hayabusa engine has a momentary power cut (feels luke a clutch kick) at high rpm, i actually thought this was a savage kind of characteristic of the engine at first coming on cam like some form of power band but the more it happens the more i think it just isnt right.

Seems to happen in every gear, around 7500 rpm ish and is 1/2 a second or so then power comes back in as if the clutch has been kicked...change gear and it happens again.

I put new plugs in before i even drove it as the previous owner said the engine needed a service.
Could it be plug gaps?

Coil packs? It has a power commander fitted also. All seems fine other than this.

Cheers for help,
Ash

CosKev3 - 11/7/18 at 05:32 AM

Have you got anyone local with a rolling road that doesn't mind tuning BEC's?

If so a session on there will probably be the best bet

TimC - 11/7/18 at 07:08 AM

quote:
Originally posted by CosKev3
Have you got anyone local with a rolling road that doesn't mind tuning BEC's?

If so a session on there will probably be the best bet


What he said. PDQ, Daytuner, TTS the ideal places.

Perpetrator - 11/7/18 at 07:10 AM

I'm not sure I could possibly find someone. I was hoping it would be a bit easier than having a full re-tune.

From what a mate of mine said he had read up on the issue it could be spark plug or coil pack related?

Could anyone recommend anyone who tunes BEC cars in the North west?

[Edited on 11/7/18 by Perpetrator]

minitici - 11/7/18 at 10:06 AM

Have you got any type of battery master switch? - These can be unreliable and start giving intermittent power breaks under vibration.

Perpetrator - 11/7/18 at 10:18 AM

quote:
Originally posted by minitici
Have you got any type of battery master switch? - These can be unreliable and start giving intermittent power breaks under vibration.


I do, ill check that, but funnily enough I was actually looking at that last night and it does look to be fitted securely and correctly, nevertheless I will give that a good check. Thanks for your suggestion.

minitici - 11/7/18 at 03:41 PM

quote:
Originally posted by Perpetrator
quote:
Originally posted by minitici
Have you got any type of battery master switch? - These can be unreliable and start giving intermittent power breaks under vibration.


I do, ill check that, but funnily enough I was actually looking at that last night and it does look to be fitted securely and correctly, nevertheless I will give that a good check. Thanks for your suggestion.


Yes - the contacts inside can get a bit iffy over time.
Some cheap knock-off copies of FIA battery master switches (sold by supposedly reputable motorsports dealers) don't even work when new!