excessive smoke right cylinder

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kawonda750
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excessive smoke right cylinder

Post by kawonda750 »

Well, I have it all back together and have a smoke screen coming from the left cylinder. I had the crank redone with bearings and new seals so I am hoping it not a seal. Changed the plugs around with no difference. Any ideas?
SRIS ? stuck oil feed valve at the cylinder? Although it doesn't seem to be hydro locked ?
It is blue smoke so I don't think it is burning coolant.

Any input would be appreciated.
Thanks
Dave
karl pa
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Re: excessive smoke right cylinder

Post by karl pa »

It could be a leaking oil feed check valve, but I would give it a good run, it should clear after it warms up and a few miles on it
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jabcb
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Re: excessive smoke right cylinder

Post by jabcb »

A few years ago the right cylinder on my gray GT750 was a smoke screen generator. Was a problem with the spark plug cap.

Also had a smokey GT250 cylinder that was due to either the carbs or ignition, or possibly both. Did a complete carb service & replaced the points+condensers, so I’m not exactly sure what fixed the issue.
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GTandcbr
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Re: excessive smoke right cylinder

Post by GTandcbr »

Definately not hydro locked it wouldn't run. +1 on giving it a good run to clear out the cylinder.
98 carb Blackbird and GT550j
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 for the input. I will cover all of the points. Timing is dead on after confirming yesterday.
kawonda750
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Re: excessive smoke right cylinder

Post by kawonda750 »

So, I have it all together. The carbs have been ultra sonically cleaned, twice. Timing is dead on. Idle is good and balanced with a vacuum gauge. Float levels are set. There is no power. It idles but when I take off it is not too impressive.
Any ideas? What would a bad condenser do? Honestly, I did not replace them when I put in new points.

I am stumped here.

Thanks
Dave
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Re: excessive smoke right cylinder

Post by GTandcbr »

So first we need to identify the bike? I think its a GT750? If so is it an early bike fitted with round slide carbs or the later one fitted with different BS40 carbs?
I would check that the exhaust baffles are clean and the exhausts are not restricted in any way.
It would also be a good thing to check engine compression with a gauge.
What is the bike battery like? If it is old or the cells are not all topped up it will fail under load.
Try using a multimeter across the terminals to find the voltage. Then start the bike and rev to 3000 and see what the meter reads. Check what voltage you have at the coils. A lot of power can be lost between the battery and coils as it goes around the loom and connector blocks.
98 carb Blackbird and GT550j
kawonda750
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Re: excessive smoke right cylinder

Post by kawonda750 »

Sorry. 74 GT750 new battery 12.9 V

I will check the baffles.

Thank you .
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Re: excessive smoke right cylinder

Post by GTandcbr »

Sorry your BS40 carbs are not my field perhaps someone else could assist :?:
98 carb Blackbird and GT550j
karl pa
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Re: excessive smoke right cylinder

Post by karl pa »

Do you have the correct Mikuni jets in carbs? Also, do you have surging issues like most 74 have?
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kawonda750
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Re: excessive smoke right cylinder

Post by kawonda750 »

I have genuine Mikuni parts. I don't know about surging because it is not running with enough power to surge.
karl pa
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Re: excessive smoke right cylinder

Post by karl pa »

kawonda750 wrote: What would a bad condenser do? Honestly, I did not replace them when I put in new points
I would replace them, to eliminate them as cause. But I wonder if it is running lean (air leaks ?) or rich causing issue, I admit I am not very good at carburetion. Did you do a compression test to make sure top end is right? You did put the right piston in the right cylinder?
Do all 3 header pipes get hot or does one feel cooler?
76 GT185
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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 »

This is likely a bad thing to say here, but I am completely frustrated and beginning to hate this bike. 74 Gt750. Complete engine rebuild, 1st oversize pistons and rings, crank rebuild, seals and bearings. New points, and condensors, replaced coils. Cleaned carbs 4 times anyway and maybe more.

It idles but when I take off it does not run on all cylinders. Timing is dead on with dial gauge and meter to tell when the points open. If I gently give it throttle when moving it seems to respond and pull but not under quick acceleration.

I have spent hour upon hour and invested a lot of money with crappy results. Open to any ideas that anyone may have.

Thanks
Dave
kawonda750
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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 »

i am now seeing that the 74 model was different. The plugs are black very fast meaning a rich mixture. I am using 45 pilot jets and 110 mains. The air screw is out 3/4 turn. Plug is B8ES.
Should I go to a smaller pilot? Or try the B6ES? I would really like to get this bike running correctly.

Thanks
karl pa
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Re: excessive smoke right cylinder

Post by karl pa »

I never used it, but some screw an adapter in bowl drain plug,then use a clear tube to show where actual fuel level is, not relying on float measurement. If fuel level in bowl is too high can cause rich issue.
I think they call for air screws to be 1/4 turn out on 74.I believe 74 calls for 47.5 pilots so your 45 are already smaller. Mains are left and right 110, center 107.5, not sure it really matters.
I use B8ES plugs in my 74, although I think they do call for B6ES
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