Help!!! Problem with CARB 1979 & 1981.

If it's broken or just needs tweaked

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Nic650
Posts: 7
Joined: Tue Oct 11, 2016 8:42 am

Help!!! Problem with CARB 1979 & 1981.

Postby Nic650 » Wed Oct 12, 2016 1:48 am

Dear,
My bike date 1979, i want to change carb cb650 1982, i bought CARB cb650 1982 included airbox & intake insulator boot cb650 1982 (part#: 16211-460-770). But all them not fit with cylinder head 1979 (part#: 12200-426-020). Then i known cylinder head 1979 & 1982 different part number. Cylinder head 1982 part #: 12200-460-770). I want to keep my cylinder head 1979 because it is very good shape (odo:11.000 km).
Pls help me this case. I dont know intake insulator else fit them, or how can custom intake insulator boot?!?
Tks so much.

cb650
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Location: Denver CO USA
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Re: Help!!! Problem with CARB 1979 & 1981.

Postby cb650 » Wed Oct 12, 2016 5:38 am

Soos had a thread here long ago about it. Seemed a lot of work. Just get 79 or 80 carbs. SOHC $ 750's fit to but then have to play with jetting.
Did you clean the tank out?!?!?!?!

Nic650
Posts: 7
Joined: Tue Oct 11, 2016 8:42 am

Re: Help!!! Problem with CARB 1979 & 1981.

Postby Nic650 » Wed Oct 12, 2016 10:59 am

Dear cb650, tks for your assistance.
I knew, but my issue: i bought carb cb650 1982 & i want to keep it, i finding any intake manifold rubber fit with my carb (cb650 date 1982). My bike is 1979. :(

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tario
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Re: Help!!! Problem with CARB 1979 & 1981.

Postby tario » Wed Oct 12, 2016 11:55 am

The easiest solution to your problem would be to make all new parts for your carburetor to change the spacing. Then your carb boots should line up. If you don't have access to a machine shop and/or value your time... buy the right parts. (like a 1979-1980 carburetor) The mechanical carbs seem to work much better anyways. (Maybe someone that has more experience will disagree; but they seem like a set-it-and-forget-it solution.)
1979 cb650
1980 cb650

Nic650
Posts: 7
Joined: Tue Oct 11, 2016 8:42 am

Re: Help!!! Problem with CARB 1979 & 1981.

Postby Nic650 » Thu Oct 20, 2016 3:18 am

Everything fit. I love my 79 cb650. I changed CV carb (cb650 1981), my exhaust 4-4, air filter UNI (high flow). But the bike run well under 5000rpm. Above 5000rpm: the bike didnt run more. When i removed Air filter, the bike run full speed. Cv carb main jet 120, i think replace main jet 120 to 110. Pls help me this case.
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cb650
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Re: Help!!! Problem with CARB 1979 & 1981.

Postby cb650 » Thu Oct 20, 2016 4:44 am

my 82 has 110 jets in it and runs very well but I am at 5k ft elevation also. I do have the filter cover off and using big flat washers to hold the filter in place. It is a stock type filter.
Did you clean the tank out?!?!?!?!

Nic650
Posts: 7
Joined: Tue Oct 11, 2016 8:42 am

Re: Help!!! Problem with CARB 1979 & 1981.

Postby Nic650 » Thu Oct 20, 2016 9:47 am

cb650 wrote:my 82 has 110 jets in it and runs very well but I am at 5k ft elevation also. I do have the filter cover off and using big flat washers to hold the filter in place. It is a stock type filter.


Dear, tks so much.

cb650
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Joined: Fri Mar 03, 2006 7:20 am
Location: Denver CO USA
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Re: Help!!! Problem with CARB 1979 & 1981.

Postby cb650 » Thu Oct 20, 2016 3:29 pm

Bike looks nice.
Did you clean the tank out?!?!?!?!

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tario
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Re: Help!!! Problem with CARB 1979 & 1981.

Postby tario » Fri Oct 21, 2016 10:13 am

How did you get the carbs to fit? Just using sections of radiator hose? If you try to run the bike over 5000rpm and look at the spark plugs it will tell you if you need more gas or more air. Try riding with the choke in and see if the reduction of air helps or hurts. Google "reading spark plugs" to see what issues you might be having.

edit; Just reread your post. Didn't see the airbox thing the first time. 110 sounds like a good starting point. You will probably have to try a few jet sizes to get this right.
1979 cb650
1980 cb650

Nic650
Posts: 7
Joined: Tue Oct 11, 2016 8:42 am

Re: Help!!! Problem with CARB 1979 & 1981.

Postby Nic650 » Sat Oct 22, 2016 8:33 am

tario wrote:How did you get the carbs to fit? Just using sections of radiator hose? If you try to run the bike over 5000rpm and look at the spark plugs it will tell you if you need more gas or more air. Try riding with the choke in and see if the reduction of air helps or hurts. Google "reading spark plugs" to see what issues you might be having.

edit; Just reread your post. Didn't see the airbox thing the first time. 110 sounds like a good starting point. You will probably have to try a few jet sizes to get this right.

Hi, yes, it is radiator hose. :). Intake boot (ninja 600) is going to ship. I'm going to replace mainjet #110 first, then double check another size.


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