excessive smoke right cylinder

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kawonda750
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Suzuki 2-Strokes: gt750, 70 Kaw H1, 72 Kaw H2
Location: penetang, ontario

Re: excessive smoke right cylinder

Post by kawonda750 »

Thanks Karl. I am new to these CV carbs but if the air screw is out 3/4 rather than 1/4 doesn't that give me a leaner mixture ? I am going to try B6ES today and see what that does. I am trying one thing at a time hoping to isolate what is going wrong. So far, it has been quite a test for my trouble shooting skills... or lack thereof....
karl pa
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Re: excessive smoke right cylinder

Post by karl pa »

On these carbs, I think they are actually fuel screws not air screws,the way I understand if the screw is between filter and carb they are air screws,if the screw is between carb and engine they are fuel screws, the 75 uses 45 pilots with screws out 3/4, they also have different cutouts in slides.
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kawonda750
Around the block
Posts: 51
Joined: Wed Nov 28, 2012 4:48 pm
Country: canada
Suzuki 2-Strokes: gt750, 70 Kaw H1, 72 Kaw H2
Location: penetang, ontario

Re: excessive smoke right cylinder

Post by kawonda750 »

Ok, that changes everything. I will try 1/4 turn next.
Thanks again.
karl pa
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Posts: 334
Joined: Sat Sep 05, 2015 3:14 pm
Country: us
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Location: southeast pa

Re: excessive smoke right cylinder

Post by karl pa »

I don't know that the mixture screws will change much with your issue. pilot circuit is mostly low throttle input, what is the condition and setting of needle and jet.And I assume you already checked air filter.
76 GT185
77 GT250
77 GT380
76 GT500
73 GT550
73 GT750
74 GT750
71 T250 scrambler
75 T500 cafe
kawonda750
Around the block
Posts: 51
Joined: Wed Nov 28, 2012 4:48 pm
Country: canada
Suzuki 2-Strokes: gt750, 70 Kaw H1, 72 Kaw H2
Location: penetang, ontario

Re: excessive smoke right cylinder

Post by kawonda750 »

At present the airbox is not on because I have been playing with the carbs. Honestly, I have not even checked the needle clip position. I tried the 1/4 turn on the mixture screws and it made a big difference. I am kicking myself because I should know better than to not have checked the needle clip.

I guess that is my next step.
kawonda750
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Suzuki 2-Strokes: gt750, 70 Kaw H1, 72 Kaw H2
Location: penetang, ontario

Re: excessive smoke right cylinder

Post by kawonda750 »

It seems that I have the wrong pilot jets. I was given the 4 hole ones that are used in the Kawasaki VM carbs where the Suzukis use 3 hole ones. I will see if these make a difference when they arrive from the Suzuki dealer.
kawonda750
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Country: canada
Suzuki 2-Strokes: gt750, 70 Kaw H1, 72 Kaw H2
Location: penetang, ontario

Re: excessive smoke right cylinder

Post by kawonda750 »

I changed to the right pilots and it seems to have worked. Of course, I forgot to put the joining bar back on so I have to remove the carbs again but , at least, I can leave the cables connected.
Thanks for the input. :mrgreen:
rngdng
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Re: excessive smoke right cylinder

Post by rngdng »

I ran into the pilot jet problem many years ago. It sucks that Mikuni has two types of pilots number the same that are SO different.


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jabcb
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Re: excessive smoke right cylinder

Post by jabcb »

Mikuni has 3 pilot jets that look similar that are 14mm long with 4.9mm thread.
BS30/96 has 6 shaft holes
N151.067 has no shaft holes
VM22/210 has 8 shaft holes
https://jetsrus.com/FAQs/FAQ_identify_that_jet.htm

VM carbs on the GT series & most of the T series use VM22/210.
See page 10 in: http://www.ozebook.com/compendium/suzi/suzidata1.htm

The VM carbs on the 72/73 GT750 use the 8-hole VM22/210. Same as those Kawasaki VM carbs.
But the CV carbs on the later GT750 use the 6-hole BS30/96.

VM & CV carbs are very different beasts.
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