The power of a backfire!

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barney01
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Joined: Wed Sep 26, 2012 7:33 pm
Location: Prestatyn.Wales

The power of a backfire!

Post by barney01 »

Riding on a fast dual carriageway yesterday at 70 mph. Came to an island and rolled off the throttle had a massive backfire. Engine cut out. Suspected fuel starvation so switched to prime on petcock and bike started. Limped back home found lower left baffle was half way out. What amazed me was the retaining bolt was still there but had been torn out!
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Always check baffles after a backfire!
Always check baffles after a backfire!
NO SMOKE .......NO POKE
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canaletto5
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Joined: Tue Jul 23, 2013 8:43 pm
Location: Derbyshire

Re: The power of a backfire!

Post by canaletto5 »

Damned noisy when it happens. I don't think it was a backfire Barney. It's the noise that the back pressure makes when it's forced the baffle out. It happened on my kettle when the retaining screw worked loose. I was running the engine on the driveway and the baffle spat across the road ! The noise nearly gave me (and my neighbour) a heart attack :lol:
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stevewharton
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Location: Grimsby, Lincolnshire.

Re: The power of a backfire!

Post by stevewharton »

Myself and a mate were travelling on the A46 near Lincoln a few years back when one of my large baffles shot out, he was behind me and said it was like an excocet missile coming at him, :roll: luckily it shot past him and didn't cause any mishaps.
We searched for ages but couldn't find it so gave up and carried on to the bikers pub where I wasn't very popular because of the excess decibels. Next day my mate came round with the baffle in his hand, he was so sure he knew where it had landed he'd gone back and found it in a field near to where it had shot out.
That was lucky because at the time a new baffle from Suzuki would probably have been a tad expensive, now you can buy replicas from Delkevic for £25 each off ebay.
P.S. I always put a small locknut on the retaining screw now so I don't lose another baffle.
Look, my paintwork hasn't got "Fish scales" :x they're "Dragon scales" right!!! However, after some thought, I will accept "Black Marlin" or "Swordfish", but definitely not "Haddock" or "Cod".
barney01
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Joined: Wed Sep 26, 2012 7:33 pm
Location: Prestatyn.Wales

Re: The power of a backfire!

Post by barney01 »

So pulled baffles out no real drama's but I notice now that the usual thing has happened on the middle lower pipes. The internal baffle supports have become detached. I'm not worried about that though have ridden for years before like that.
However I am thinking about tacking the build up of sludge inside the pipes. I know several methods including the frayed clutch cable in the drill and the caustic soda method.
Only problem I can see is wot the ell do you do with the waste caustic soda afterwards?
NO SMOKE .......NO POKE
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PaulD738
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Re: The power of a backfire!

Post by PaulD738 »

It makes cracking drain cleaner ;)
They're rubbish them Jap bikes lad they won't last five minutes! you want to get yourself a nice Royal Enfield!
A quote from my old dad 8-)

I started out with nothing and I’ve got most of it left!
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Scotch750
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Location: Walsall, West Mids.Black Country.

Re: The power of a backfire!

Post by Scotch750 »

barney01 wrote:So pulled baffles out no real drama's but I notice now that the usual thing has happened on the middle lower pipes. The internal baffle supports have become detached. I'm not worried about that though have ridden for years before like that.
However I am thinking about tacking the build up of sludge inside the pipes. I know several methods including the frayed clutch cable in the drill and the caustic soda method.
Only problem I can see is wot the ell do you do with the waste caustic soda afterwards?
Wuh, if you hang your pipes in Trichloroethylene (now outlawed) the sh.t just runs out but your hands go white and dry up FAST.
Done this in 1978 with my 380 pipes ! I was only 12 :o
People think I'm MAD ! Nothing to do with working with chemicals :shock:
Or try Proscale 650.
Sorry, to answer your question. Put it in a container and put your nuts in it !!.....oh sorry and and your bolts and I reckon they'll clean up good. Let me know.
Cheers Scotch.
Oh, by the way. I'm still MAD :D
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Alan H
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Location: Wombwell, Republic of South Yorkshire

Re: The power of a backfire!

Post by Alan H »

Soak the inside of the silencers in petrol, stand them up (engine end up) against a wall and chuck matches at the bottom. There will be a bang (honest!) and the petrol will burn, so will all the crap inside the exhausts. Repeat as necessary. Of course, if you use semi synth 2T oil, it don't get that bad.

Joys of two stroke ownership.
Proof that four strokes are over complicated
teazer
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Re: The power of a backfire!

Post by teazer »

Put that one on youtube so we can see how badly you were burned and how bad the pipes were after.

Burning off the oily crap is one way to get baffles clean and sort of works with pipes that you don't mind if/when they get discolored. A better way is probably a hot tank dunk - that's a hot caustic soda tank and rinse if anyone still has one of those. There's a picture on Ian Sandy's site that shows how much carbon collects inside a pipe.

A big issue on those stock pipes is if the front absorbtion mats come loose and partially block exhaust gas flow.

But more to the point, what caused there to be so much unburned fuel in the exhaust in the first place?
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