Backfiring
- Hawk1
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When idling cold just after start up there are some
Backfiring from exhaust. Not much but annoying.
When warmed nothing.
The bike is KZ1000A2 ´78 stock.
:huh:
Hawk1
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- Reichmanner
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1981 kz750 ltd (Project BOB)
1982 kz750 Spectra (Project Street Fighter)
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- faffi
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1977 KZ650B1
1980 F1 engine
B1 3-phase alternator
B1 Points ignition
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- Hawk1
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I will take a better look at it. Same problem on my friends Z1.
Thanks again,
faffi wrote: Could be plenty of causes, from a leaky exhaust valve to a bad spark plug. I would start with a full tune-up; points/condencer check, new spark plugs, coil and HT lead check, spark plug caps check, timing check, valve clearance check, compression check and carb clean and synch. But before all that you can check for leaks by spraying starter fluid around the inlets and see if revs climb.
Hawk1
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- faffi
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The reason for the popping is incomplete burning. As mentioned, there are lots of issues that can cause this, and a full tune-up is the easiest way to eliminate the most common causes.
A leak in the exhaust system can make it easier for unburned fuel to ignite, and since the exhaust becomes hot with time such a leak can seal itself. Or the hotter engine can be the help as it will burn much cleaner when it's nice and warm than when cold.
1977 KZ650B1
1980 F1 engine
B1 3-phase alternator
B1 Points ignition
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- Hawk1
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some maintains then sometimes it too much...
I’m the one of the blokes who is always chasing for near
as perfection and therefore wasting maybe to much time in
the garage at the winter time. (Single..!!)
But the riding season.., its one big smile instead…
Hawk1
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- Polar_Bus
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Hawk1 wrote: Just wondering. Well stupid question mabey.
When idling cold just after start up there are some
Backfiring from exhaust. Not much but annoying.
When warmed nothing.
The bike is KZ1000A2 ´78 stock.
:huh:
You possibly have an air leak. Does the bike pop through the exhaust when you let off the gas when riding ? If yes then you have a exhaust system seal leak somewhere. You also might have your air screws set a bit too lean. Try richening the screws 1/2 turn. Last resort (I did this on my GS1100) was to bump the pilot jets one size richer. This made a huge positive difference in my GS's cold start idle and warmup behavior. It also rid my bike of a frustrating slight stumble "off idle"
Bikes:
'84 GPz1100
'06 HD Fatboy
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- Hawk1
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Small pops and nothing when warmed up.
Hawk1
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- faffi
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1977 KZ650B1
1980 F1 engine
B1 3-phase alternator
B1 Points ignition
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- Polar_Bus
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Hawk1 wrote: Only pop through the exhaust when idling and only when cold.
Small pops and nothing when warmed up.
Try richening the air screws 1/2 turn, that should make an improvement.
Bikes:
'84 GPz1100
'06 HD Fatboy
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