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Administrator
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It has got to be something simple that I'm overlooking. I'm completely stumped.
Recap: I wrecked and boogered up my ignition advancer and pulse generators.They little ''sensor'' tips were heavily scratched up,but they seemed to be working ok. The bike idles smooth and revs nicely in neutral,but there is a roughness to it. The rpm's at idle is smooth,no variations,but you can feel the engine run. Before it was so smooth you couldn't feel it running while idling and only a slight buzz when you revved it hard. In gear it's still quick and snappy,but at upper rpms it starts breaking up. Not a full on miss,but lays over and quits making power.
Another new symptom is the #4 exhaust pipe is starting to yellow the chrome since all this started.
I picked up another set of pulse generators and a ignition advancer off a running bike that got parted out. Installed them,static timed it, ran it and set both pulse generators with a light. Spot on the marks according to the FSM. No difference in performance compared to my wrecked units.
I borrowed a pair of spark units just to test and there's no difference there either. So it would appear that my ignition is just fine. All 4 cylinders are firing and timed correctly. Very stable spark when veiwed with a light.
Carburetion was perfect before the wreck,so I know it's not the pods playing tricks on me. The carbs didn't hit the road when the bike slid and were JUST gone through and synched.
So what the heck?!?! What would you look at next? I guess I could check the carbs since it did lay on it's side for a few moments,but I can't see how that would create an issue.
The bike starts,idles and motors around perfectly fine. Just has a just-noticeable vibration at idle and won;t pull in upper rpms. The yellowing exhaust pipe is a sign of too-hot exhaust temps. It's not timing related since all that is spot on and I can't understand how it could be a lean cylinder caused by this wreck.
Hit me with any ideas you have. I'm completely out of ideas myself. Thanks.
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Administrator
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It's a CARB problem!
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."
1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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Administrator
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Oh, and you have too many cams.  TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."
1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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Did you bend the crank? Check it with a dial indicator.
89 VN 750A - Given to son-in-law
79 CB 750K-sold 3 May 21
78 CB 750K
77 CB 750K
77 GL 1000 x 2
77 CB 550F
Holton, KS, US
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Administrator
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rich wrote
Did you bend the crank? Check it with a dial indicator.
Now that is a good thought! I have seen bent cranks from wrecks.
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."
1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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Administrator
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 I'll go check...
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Administrator
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Whew! Crank is OK.
Gonna check cam timing now.
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Administrator
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In that case, it's your carbs, or the No#4 carb.
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."
1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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Administrator
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That's what I was thinking. I can't see timing only affecting one cylinder like that.
But at least I know the chain didn't jump. Cam phasing is spot on.
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Administrator
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Haven't pulled the carbs yet, but I no longer hate the valve cover on these dohc bikes. I love how they seal. It'd be a bummer if you had a bad rubber on one of the mounting bolts, though.
The cam lobes are massive compared to single cam bikes and the valvetrain situation is awesome.
It's pretty impressive, the refinements from one generation to the next. The twin Cams don't get enough respect.
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something w/the jet needle ? bent?
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Administrator
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Very well could be. Hope to get the carbs off tomorrow night and take a peek. I'm running out of ideas.
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Administrator
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I have heard of jets being knocked loose, usually the idle jet or low speed since they press in.
The ride IS the adventure. The destination is just to get gas!
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Locked
