Trap for us less educated

[old slider]

Took my HD through to Anza for the big 32000km service, riding back to Wanganui the Screaming Eagle super tuner appeared to have done its job, my only complaint is I that think the steering head bearing that was lubricated etc was re-adjusted just a tad too free. The vibration certainly changes when you apply the front brake off and on while sitting at idle.(maybe that's normal?)

Sorry I digress, I had done a few hundred Kms since this service when the Bike developed a horrendous very loud single Backfire on startup, no hesitation to start, just a window smashing gunshot blast that frightened the neighbours and made children cry, Fuck it I thought, whats gone wrong with the expensive tune up. The bike seemed to run ok at all revs, apart from a slightly different vibration, or was I imagining it. Suddenly after making copious enquiries as to the possible cause the backfire suddenly vanished, vibration felt back to normal again.

What Had I done different? Nothing really, I had simply refueled at a different servo (same brand) than my usual, as soon as I refueled at my regular the backfire vanished and 3 tanks later it has not reappeared. Very pleased I didn't make the run back to Palmy to have it looked at, is it easy to get a bad fill up at some servos?

[Akzle]

copious amounts have been written on this. don't fill up in the morning, or after the tanker's just been (condensation and stirred up sediment respectively)

mobil 95 tested cleanest (most used in rc)

but whatever suits your engine.

[old slider]

copious amounts have been written on this. don't fill up in the morning, or after the tanker's just been (condensation and stirred up sediment respectively)

mobil 95 tested cleanest (most used in rc)

but whatever suits your engine.

Thanks for the heads up Akzle, yes, it must be frustrating when us less than competent and often older keyboard users forget about using the search function.

[Akzle]

Thanks for the heads up Akzle, yes, it must be frustrating when us less than competent and often older keyboard users forget about using the search function.

don't worry old chap, no frustration here, or i'd've been a damn sight shorter.
but i'm sure a google will bring up plenty.

[Old Steve]

You do know, don't you, that the "91 Octane" recommended for HD is American Octane which is:

Research Octane number (RON) + Motor Octane number (MON) divided by 2

NZ fuel is rated by it's RON only, and has a sensitivity around 10 octane numbers (ie. the difference between RON and MON)

So the closest to American 91 Octane is 95 RON here in NZ. Even better if you can get 98 RON at a service station that sells it, though the sensitivity of that may be a little greater.

Not that a tank of low octane fuel would cause backfiring. But just thought I'd take this opportunity to remind HD riders of this American peculiarity.

[old slider]

You do know, don't you, that the "91 Octane" recommended for HD is American Octane which is:

Research Octane number (RON) + Motor Octane number (MON) divided by 2

NZ fuel is rated by it's RON only, and has a sensitivity around 10 octane numbers (ie. the difference between RON and MON)

So the closest to American 91 Octane is 95 RON here in NZ. Even better if you can get 98 RON at a service station that sells it, though the sensitivity of that may be a little greater.

Not that a tank of low octane fuel would cause backfiring. But just thought I'd take this opportunity to remind HD riders of this American peculiarity.

Yes, thanks Old Steve I learnt a lot reading the thread on which fuel to use and the differences. I did a bit of investigation, ie asked a few people that I know who used this servo and some had encountered problems with their outboard engines after refueling, this is the only servo close to the boat slipway and the suburb, hopefully it was a one off incident, the guy I talked to at the counter was not aware of any fuel problems, but would tell the owner of my concerns.

[Cosmik de Bris]

Servo???? This is New Zealand we don't have servos. Jeez.

[Ulsterkiwi]

I got a fill of 95 at the wee GAS station in National Park back in January. The bike (Aprilia) had been running sweetly up until then. Filled up just before we checked in to the accommodation for the night. Next day the bike ran like shite. So much so I stopped in with the Aprilia guy in Hamilton to get it checked out. He diagnosed old fuel and prescribed injector cleaner and burn through the old stuff as quickly as possible. We were headed to cape Reinga so it wasn't an issue. Took a few fills but the bike eventually settled.annoying when these things happen. Maybe smaller stations don't sell so much 95 and it sits in the tanks longer?


Sent from my iPhone using Tapatalk

[ellipsis]

...unrelatedly related but...my Stihl saw has run on avgas for all its 25 years of cutting...there was always race gas left after a meeting and it all got put aside for the chainsaw...having not been out racing as much recently , my avgas run out and I had to resort to putting some 95 in it from the local pump...it ran roughly for ten seconds and then stopped...put the saw away until I could get into town to get some avgas, drained it, replaced with good stuff...running like a dream as soon as I pulled the starter cord...

[jasonu]

Servo???? This is New Zealand we don't have servos. Jeez.

There sure as shit 'aint any actual service either. Just some curry muncher at the till who barely makes eye contact and doesn't say thank you.

[Zedder]

There sure as shit 'aint any actual service either. Just some curry muncher at the till who barely makes eye contact and doesn't say thank you.

The last time I was in Oregon USA, it was illegal to pump your own gas. Great service due to all the thousands of fuel attendants needed in that state although the fuel was more expensive of course...

[old slider]

I got a fill of 95 at the wee GAS station in National Park back in January. The bike (Aprilia) had been running sweetly up until then. Filled up just before we checked in to the accommodation for the night. Next day the bike ran like shite. So much so I stopped in with the Aprilia guy in Hamilton to get it checked out. He diagnosed old fuel and prescribed injector cleaner and burn through the old stuff as quickly as possible. We were headed to cape Reinga so it wasn't an issue. Took a few fills but the bike eventually settled.annoying when these things happen. Maybe smaller stations don't sell so much 95 and it sits in the tanks longer?


Sent from my iPhone using Tapatalk

Interesting, as an aside, do you think the higher altitude could cause any issues?

As for servo, Cosmik de Bris it beats having to type out "Service Station" especially when your a one finger at a time type of bloke, rather than jumping in fists and all.

[Ulsterkiwi]

Interesting, as an aside, do you think the higher altitude could cause any issues?

As for servo, Cosmik de Bris it beats having to type out "Service Station" especially when your a one finger at a time type of bloke, rather than jumping in fists and all.

I did wonder about that. Had it been a carbureted motor not an all singing all dancing electroniced to hell and back thingumy then absolutely. The ECU should have been able to cope with altitude. If anything it should have been a richer mix not felt as lean as a lean thing.
I also wondered about moisture/condensation after sitting outside in the relative cold but a) the tank had just been filled to the brim and b) it's a plastic tank.
The poor quality fuel thing made most sense and given the problem resolved sort of reinforces the case for that idea

Glad you got sorted too!


Sent from my iPhone using Tapatalk

[Night Falcon]

Thanks for the heads up Akzle, yes, it must be frustrating when us less than competent and often older keyboard users forget about using the search function.

Akzle posted a valid comment....maybe I should un-ignore him?

[Akzle]

Akzle posted a valid comment....maybe I should un-ignore him?

no. fuck off cunt.