Occasional carb backfire
01-26-2007, 04:21 PM
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Occasional carb backfire
So I've got the stock air filter back in now cause the bike was running all screwy with the K&N.... Only mod motor-wise is the slipons right now. Occasionally, esp when its cold out, the bike will make a thunk/tap noise and drop 200 rpms and back to a normal steady idle, sounds like a carb backfire. Any ideas what could be causing this? Carbs out of adjustment maybe? Plugs have been done, dont know if the carbs have ever been adjusted or resynched, bike *did* sit for a while (only 11k miles and a 98 model).
Thanks guys....I'm debating playing with the carbs myself but I haven't done much work with carburetors before, I'm an EFI tuning guy more than anything...
Thanks guys....I'm debating playing with the carbs myself but I haven't done much work with carburetors before, I'm an EFI tuning guy more than anything...
01-26-2007, 09:53 PM
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same thing happens to my 98 always when I go to rev hear a pop and spit kinda thing , then goes right back to normal rpm's?have k&n and dynojeted w/tbr pipes. but other than that the power is great is this somethin i should worry about?
01-27-2007, 03:47 PM
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Appreciate the info.....checked your site out Greg, I'm really debating buying that Twinmax thing and doing the tweaking myself, seeing as I plan to have the hawk for the long haul... I've just never worked on carburetors before, but it seems simple enough....
01-27-2007, 07:53 PM
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01-28-2007, 08:51 AM
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Same thing was happening to my 2001. I changed the spark plugs and decided to disable the P.A.I.R. valves when I found one of the reeds had broken allowing hot exuast to enter the air box. No good. Went to the Honda dealership bought a new reed valve and have not heard a hic-up since!
01-28-2007, 10:36 AM
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This is true, but a broken reed in a p.a.i.r. valve serves as a window for hot exhaust to enter the airbox constantly, and that can't be a good thing It's worth takeing a look at and while your down ther you can disable the pair valves which make the bike sound a little more pleasant and supposedly run cooler. You can find insrtuctions at Greg's Honda literbikes online.
01-28-2007, 03:40 PM
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Roisman, 2 full turns, as in 720 degrees.
Birdoprey, with anything other than stock exhaust you will have an increase in popping on decel. Not really a backfire, just the unburnt fuel combusting in the pipes. That's why most disable PAIR, cuz it's annoying, though some think it sounds cool.
Birdoprey, with anything other than stock exhaust you will have an increase in popping on decel. Not really a backfire, just the unburnt fuel combusting in the pipes. That's why most disable PAIR, cuz it's annoying, though some think it sounds cool.
01-28-2007, 04:27 PM
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As long as I know the exhaust pops are PAIR, it's all good. As for the carb backfires, I'm due for a tune and rejet as it is....so maybe I'll just get the twinmax, sync the carbs myself, and throw the K+N back in and take it to have the rejet done.
By the way in that K+N kit, it has these little rubber cap-offs that cover these two inlets, I thought they may have had something to do with a type of EGR system (I'm a car guy okay).....would those be the PAIR inlets?
By the way in that K+N kit, it has these little rubber cap-offs that cover these two inlets, I thought they may have had something to do with a type of EGR system (I'm a car guy okay).....would those be the PAIR inlets?
01-28-2007, 07:33 PM
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Hawkrider, good to know. now I just have to convince the wife that I have to get slip-ons before they stop making them. you know, the bikes out of production and all...better jump to it...soon. what? yes dear, coming.
01-28-2007, 08:42 PM
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As long as I know the exhaust pops are PAIR, it's all good. As for the carb backfires, I'm due for a tune and rejet as it is....so maybe I'll just get the twinmax, sync the carbs myself, and throw the K+N back in and take it to have the rejet done.
By the way in that K+N kit, it has these little rubber cap-offs that cover these two inlets, I thought they may have had something to do with a type of EGR system (I'm a car guy okay).....would those be the PAIR inlets?
By the way in that K+N kit, it has these little rubber cap-offs that cover these two inlets, I thought they may have had something to do with a type of EGR system (I'm a car guy okay).....would those be the PAIR inlets?
01-28-2007, 09:13 PM
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The standard filter has them built in as well somehow I think, so the end result is the same. The K&N just does it with separate caps.
There is no airflow into the engine via these inlets. They just allow the diaphragms to operate.
There is no airflow into the engine via these inlets. They just allow the diaphragms to operate.
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