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Headers glowing red on cbr1100xx mini
alowry - 4/4/20 at 10:37 AM

Hi,

I'm hoping someone can give me a bit of advice on my injected blackbird powered mini build. I've noticed the headers glow red hot when the car is warming up & when the engine is held at a steady 2000rpm or above for more than 20secs or so.

I'm concerned this may indicate the engines running lean?

The headers & exhaust are custom although nothing out of the ordinary as far as design is concerned. The airbox had slight modifications on the intake side of the filter. Otherwise the engine is standard.

I've added a power commander usb 111 using a map for a full race exhaust but it has no effect on the above.


Any help or advice greatly appreciated.

Adam.

[Edited on 4/4/20 by alowry]


SPYDER - 4/4/20 at 10:48 AM

It might also indicate retarded timing. Can you adjust low load timing using the Power Commander?
Is it carbs or EFI? Your airbox mods might have upset the mixture.

[Edited on 4/4/20 by SPYDER]


alowry - 4/4/20 at 10:53 AM

Cheers for that, not sure about the power commander, I'll find out. It's an injected cbr1100xx, I'll edit my post.

Adam.


cliftyhanger - 4/4/20 at 12:47 PM

I would second checking the ignition timing.


alowry - 4/4/20 at 03:41 PM

I should add; I've disconnected the power commander returning the engine to stock map & am having the same issue.

Cheers.


perksy - 5/4/20 at 10:56 AM

As above I'd be checking mixture and timing

Appreciate that bike engines run pretty hot though and I'm reliably informed that its not unknown for the manifold to glow when getting through an IVA emissions test

Just a though you mention stock map? That would be the stock map whilst the engines in the bike and not in a car ??


alowry - 5/4/20 at 11:56 AM

Thanks for the reply's, all very much appreciated.

Yes, the power commander is now disconnected & the engine is running on the original ecu as was in the bike. Therefore i'm assuming the mixture & timing should also be standard. I appreciate this won't be correct under load in a car but I've yet to get to that stage.

Any thoughts on what could have changed either of them?

I did wonder if the fuel pressure could be lower as the tank is now approx 2m of fuel line away from the engine, but as the pump is supplying greater pressure than required & regulated by the fpr on the injector rail I can't imagine that's an issue.

The airbox has what I imagine is a map or maf sensor, would a leak on that metered side be sufficient to cause a lean situation at such low revs?

I work full time in the fire service so haven't been able to get a good look to check yet.

Adam.


alowry - 7/7/20 at 08:19 PM

Quick update. Blocked off the pair valves & problem was solved!


coyoteboy - 8/7/20 at 06:13 PM

So you were seeing enough unburnt fuel in the exhaust for the secondary air injection to cause the headers to glow?

I'm no bike engine expert but that seems...odd.


JekRankin - 8/7/20 at 07:08 PM

When my r1 was on the IVA emissions map, the headers could be seen to glow red at night at idle. Wasn't obvious during daylight however. I didn't ever check if the same thing happened after it was remapped.

Jek