Author Topic: CB500 main jet size  (Read 1153 times)

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Offline rtbmrgl

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CB500 main jet size
« on: September 13, 2016, 05:00:16 PM »
Hello, my 1973 cb500 with stock exhaust and air filter box.
The main jets in them now are 86, the book says the stock jet is 100. Does this sound right.
 Doesnt seem rich but I havent done a full throttle, kill the engine and pull the plugs test.
Was wondering what others have as far as main jets
thanks, Mark
Roseville, Ca

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1973 CB500 back yard find 1243 orig mi,  http://forums.sohc4.net/index.php?topic=124285.0
1976 CB750 Restoring,        http://forums.sohc4.net/index.php?topic=132997

Offline jonda500

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Re: CB500 main jet size
« Reply #1 on: September 13, 2016, 05:26:14 PM »
Mine are #105 (stock exhaust and filter). Unless you have restricted the air intake, (like european models with #78's where the air has to get through a little snorkel) I don't know how you can ride it with #86 main jets - I didn't even know you could get #86, the sizes are normally 95,98,100,105,110. How did you determine that you have #86's?
John
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Offline rtbmrgl

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Re: CB500 main jet size
« Reply #2 on: September 13, 2016, 05:42:53 PM »
Thanks for reply, I have the carbs off, a slow jet is plugged. I dont ride often, I removed to clean and inspect.
thanks, Mark
Roseville, Ca

Got Points!

1973 CB500 back yard find 1243 orig mi,  http://forums.sohc4.net/index.php?topic=124285.0
1976 CB750 Restoring,        http://forums.sohc4.net/index.php?topic=132997

Offline Moosey

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Re: CB500 main jet size
« Reply #3 on: September 13, 2016, 05:52:55 PM »
I was having problems with my bike not idling at all. It would just die at idle. (Previous owner had "rebuild" the carbs) I pulled the carbs to check the floats and discovered that he had put in 86 main jets and aftermarket slow jets. I installed 100 main jets and original keihin slow jets. The bike runs like a top now.

Offline rtbmrgl

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Re: CB500 main jet size
« Reply #4 on: September 13, 2016, 07:51:59 PM »
I just bought a set of Keihin  #40 slow jets, I do have the original #100 mains, ill put them in a see how it runs.
thanks, Mark
Roseville, Ca

Got Points!

1973 CB500 back yard find 1243 orig mi,  http://forums.sohc4.net/index.php?topic=124285.0
1976 CB750 Restoring,        http://forums.sohc4.net/index.php?topic=132997

Offline Deltarider

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Re: CB500 main jet size
« Reply #5 on: September 13, 2016, 10:59:49 PM »
98 reads 86 when held upside down  ;D Just my 2 cnts.
« Last Edit: September 13, 2016, 11:03:07 PM by Deltarider »
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Offline rtbmrgl

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Re: CB500 main jet size
« Reply #7 on: September 14, 2016, 10:31:11 AM »
s.o.b., got me , its 98,  :-[
like to old saying goes, two keyboards are better than one, ::)
 im also on access-norton fourm and they too have sharp eyes.

thanks again.
thanks, Mark
Roseville, Ca

Got Points!

1973 CB500 back yard find 1243 orig mi,  http://forums.sohc4.net/index.php?topic=124285.0
1976 CB750 Restoring,        http://forums.sohc4.net/index.php?topic=132997

Offline BomberMann650

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Re: CB500 main jet size
« Reply #8 on: September 14, 2016, 11:20:43 AM »
98 reads 86 when held upside down  ;D Just my 2 cnts.

HAHA

Told ya dave was born on the half minute!

Offline DaveBarbier

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Re: CB500 main jet size
« Reply #9 on: September 14, 2016, 12:11:31 PM »
98 reads 86 when held upside down  ;D Just my 2 cnts.

HAHA

Told ya dave was born on the half minute!

I really want Delta to be right. Reminds me of that Cheers episode with the raffle/lottery.

Offline rtbmrgl

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Re: CB500 main jet size
« Reply #10 on: September 14, 2016, 04:17:26 PM »
98 reads 86 when held upside down  ;D Just my 2 cnts.

HAHA

Told ya dave was born on the half minute!

I really want Delta to be right. Reminds me of that Cheers episode with the raffle/lottery.

Ok for everyone a round of beers, Im drinking Newcastle brown ale.............
thanks, Mark
Roseville, Ca

Got Points!

1973 CB500 back yard find 1243 orig mi,  http://forums.sohc4.net/index.php?topic=124285.0
1976 CB750 Restoring,        http://forums.sohc4.net/index.php?topic=132997

Offline BomberMann650

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Re: CB500 main jet size
« Reply #11 on: September 15, 2016, 12:10:22 AM »
98 reads 86 when held upside down  ;D Just my 2 cnts.

HAHA

Told ya dave was born on the half minute!

I really want Delta to be right. Reminds me of that Cheers episode with the raffle/lottery.

Oh damn I read the layout wrong, Dave, you an delta both are clever devils  ;D