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Discussion Starter · #1 ·
Hey guys my bike is "coughing" when I'm slowing down or coasting haven't done a carb job or synced the quad carb yet currently building a manometer. Any suggestions other than that. Also my wiring is ****ed all the essentials work but the horn dosent and the solenoid cuts the bike off mid ride if it gets moved a little. Happened the other day riding down Sunset Blvd ??help please.
 

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2003 Buell XB9S, 1989 Yamaha Radian YX600
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My guess is the mixture is lean, which causes a misfire on decel. The unburned fuel and air then ignites inside the super hot exhaust, leading to a pop (cough).

Could be slightly clogged pilot jets? Improperly set idle mixture screws? Something like that. Think you're going to be stuck cleaning/rebuilding carbs for a while.
 

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Discussion Starter · #4 ·
My guess is the mixture is lean, which causes a misfire on decel. The unburned fuel and air then ignites inside the super hot exhaust, leading to a pop (cough).

Could be slightly clogged pilot jets? Improperly set idle mixture screws? Something like that. Think you're going to be stuck cleaning/rebuilding carbs for a while.
The coughing is through the intake it's not happening much on the exhaust
 

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The coughing is through the intake it's not happening much on the exhaust

Yep, that means lean. About those carbs--- All I can figure out is the guy who designed the Magna must have lost family members when we bombed Japan in WWII. [and designed the Magna carbs to get revenge on us.]Use the SeaFoam in them because they area bugger to get out. You have to pull the radiator and loosen up the coil pack to get them out,among other things] The idle circuit is only accessible to clean by drilling out the Welsh plugs inside the carbs to get at the idle jets. It is also very easy to break a fuel tee when working on the carbs

I saw a sign in a motorcycle shop that works on old Japanese bikes--" We don't work on Magnas, so Don"t Ask! "
 

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Discussion Starter · #6 ·
The coughing is through the intake it's not happening much on the exhaust

Yep, that means lean. About those carbs--- All I can figure out is the guy who designed the Magna must have lost family members when we bombed Japan in WWII. [and designed the Magna carbs to get revenge on us.]Use the SeaFoam in them because they area bugger to get out. You have to pull the radiator and loosen up the coil pack to get them out,among other things] The idle circuit is only accessible to clean by drilling out the Welsh plugs inside the carbs to get at the idle jets. It is also very easy to break a fuel tee when working on the carbs

I saw a sign in a motorcycle shop that works on old Japanese bikes--" We don't work on Magnas, so Don"t Ask! "
Oh geez I'm in for a real fun time... Thanks lemme see what I can do
 

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Discussion Starter · #8 ·

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Maybe...... When I see Honda parts found in the factory parts fiche, I just enter the number into the open internet search engine. Sometimes the parts have an aftermarket equivalent.

BTW, one of the best places to find ALL the honda parts numbers is Partzilla. Partzilla lists all thenumbers, even if thepart has been discontinued by Honda.

When it comes to carb kits, the quality of the rubber used in some of the kits is not good, just so you know. These guys are better than some. https://newmotorcycleparts.net/fuel_system_parts/carb_kit_hon.html I am going to buy some O-rings from them for a Gold Wing and if I have no success, I will send the carbs to Nixon for a rebuild.

BTW, use as many OEM brass parts as you can. There is no reason to throw away stuff like emulsifier tubes just because the stuff from a kit is shiny and new.

Oh, and if you need just one o-ring or the other--- https://newmotorcycleparts.net/fuel...tml#Various_O-Rings_Specific_to_Kei-Hin_Carbs
 

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Yep, that means lean. About those carbs--- All I can figure out is the guy who designed the Magna must have lost family members when we bombed Japan in WWII. [and designed the Magna carbs to get revenge on us.]Use the SeaFoam in them because they area bugger to get out. You have to pull the radiator and loosen up the coil pack to get them out,among other things] The idle circuit is only accessible to clean by drilling out the Welsh plugs inside the carbs to get at the idle jets. It is also very easy to break a fuel tee when working on the carbs

I saw a sign in a motorcycle shop that works on old Japanese bikes--" We don't work on Magnas, so Don"t Ask! "
Many years ago, I bought a used Magna 700 which had a "rough idle" and was hard to start. After searching for a very long time, I finally found a motorcycle mechanic who would work on it. To be fair, he was honest up front and said it would take a long time and a lot of money. He eventually got it running correctly at almost the cost of giving up a "first-born male". It ran like a beast for a very short period. Dead fuel pump. Once again, back to the shop. I eventually got it back and running better than ever. Then I traded it as fast as I could before it broke my bank. It spent more time in the shop than between my legs. I was out of money and patience.

Now I ride a Shadow and do most of the work on it myself. I've owned singles, vertical twins, V-twins, in-line fours, one V-four, air cooled, liquid cooled, 2-stroke and 4-stroke, chain drive and shaft drive. I liked them all and each had its own personality. I would do it all over again. But now, at my stage of life, I will take simplicity, reliability and comfort over everything else. I want to enjoy the ride and I'm not in a hurry to get anywhere. When my wife asks me where I'm going riding and when I'll be back, I always answer "I don't know yet."
 

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Discussion Starter · #11 ·
Yep, that means lean. About those carbs--- All I can figure out is the guy who designed the Magna must have lost family members when we bombed Japan in WWII. [and designed the Magna carbs to get revenge on us.]Use the SeaFoam in them because they area bugger to get out. You have to pull the radiator and loosen up the coil pack to get them out,among other things] The idle circuit is only accessible to clean by drilling out the Welsh plugs inside the carbs to get at the idle jets. It is also very easy to break a fuel tee when working on the carbs

I saw a sign in a motorcycle shop that works on old Japanese bikes--" We don't work on Magnas, so Don"t Ask! "
Many years ago, I bought a used Magna 700 which had a "rough idle" and was hard to start. After searching for a very long time, I finally found a motorcycle mechanic who would work on it. To be fair, he was honest up front and said it would take a long time and a lot of money. He eventually got it running correctly at almost the cost of giving up a "first-born male". It ran like a beast for a very short period. Dead fuel pump. Once again, back to the shop. I eventually got it back and running better than ever. Then I traded it as fast as I could before it broke my bank. It spent more time in the shop than between my legs. I was out of money and patience.

Now I ride a Shadow and do most of the work on it myself. I've owned singles, vertical twins, V-twins, in-line fours, one V-four, air cooled, liquid cooled, 2-stroke and 4-stroke, chain drive and shaft drive. I liked them all and each had its own personality. I would do it all over again. But now, at my stage of life, I will take simplicity, reliability and comfort over everything else. I want to enjoy the ride and I'm not in a hurry to get anywhere. When my wife asks me where I'm going riding and when I'll be back, I always answer "I don't know yet."
I'm going to bring it to a shop unless I have to bore the cylinders out even then I'll do the top end rebuild and jetting my self I enjoy the work and find it rewarding. I haven't worked on a bike in years so I just need some help along the way. I have a new solenoid on order and 4 carb rebuild kits. After a carb rebuild and sync we'll see how she's purring and if cylinder 2 decides to kick in. If not on to a top end rebuild. If it comes to that hopefully it's just a position ring replacment or something simple, but when is it??!

Thanks for all the help guys I'll keep you updated.
 

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I'm going to bring it to a shop unless I have to bore the cylinders out even then I'll do the top end rebuild and jetting my self I enjoy the work and find it rewarding. I haven't worked on a bike in years so I just need some help along the way. I have a new solenoid on order and 4 carb rebuild kits. After a carb rebuild and sync we'll see how she's purring and if cylinder 2 decides to kick in. If not on to a top end rebuild. If it comes to that hopefully it's just a position ring replacment or something simple, but when is it??!

Thanks for all the help guys I'll keep you updated.
Did the rebuild kit for the for carburetors jetted it five or six different times first time I did it took me 6 hours to get the carburetors out following the book now I have it down to about an hour and a half radiator does not need to come out coil packs don't need to get loosen but you still need small hands and lots of patience but I do agree with the comment on whoever designed it must have had family killed in World War II the book even says this might look impossible but the carburetors will come out this side and they do good luck
 
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