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78 Head Swap Issue's

Only thing is I never touched the Needle's though. Their in the same Position They were in with the old Head. Maybe Your onto something.
 
netwurk13 said:
Could the head be cracked through any intake passages?
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Possibly, but I don't think so.
dirtdigger said:
As I tell everyone, easiest and fastest way to jet is using the choke. When riding get to the trouble spot and hold the throttle, start closing the choke, if the engine picks up then its lean, if it stays about the same or bogs down its already too rich. These carbs are harder to jet because you have to use shims to change the needle position. Many people only try pilot and main jets which is a mistake. The needle jet has more affect of more of the throttle range than either of the fixed jets in the carb.
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Ok so with My Carb's the Number 2 is a Fixed Master that You sync the other Needle's to. And I really can't see a way to adjust that master needle.
 
Um you need to send pics of your carbs because non of the carbs have the needles adjustable like that. The round tops are adjusted with clip position and the keyholes are adjusted with shims under the needle clip. I think you are confusing adjusting the needle and adjusting the slide...the slide is adjusted with the nut and screw not the needles.

The pics of your plugs definitely dont look lean. Looks tan to brown and actually a little rich. The weirdness on the insulator looks like it could be oil usage in that cylinder.
 
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dirtdigger said:
Um you need to send pics of your carbs because non of the carbs have the needles adjustable like that. The round tops are adjusted with clip position and the keyholes are adjusted with shims under the needle clip. I think you are confusing adjusting the needle and adjusting the slide...the slide is adjusted with the nut and screw not the needles.

The pics of your plugs definitely dont look lean. Looks tan to brown and actually a little rich. The weirdness on the insulator looks like it could be oil usage in that cylinLoo
Click to expand...

dirtdigger said:
Um you need to send pics of your carbs because non of the carbs have the needles adjustable like that. The round tops are adjusted with clip position and the keyholes are adjusted with shims under the needle clip. I think you are confusing adjusting the needle and adjusting the slide...the slide is adjusted with the nut and screw not the needles.

The pics of your plugs definitely dont look lean. Looks tan to brown and actually a little rich. The weirdness on the insulator looks like it could be oil usage in that cylinder.
Click to expand...
Looking into things a little more it looks like I'm Wrong. What I thought was adjusting the Needle is actually adjusting the entire slide. And I do need Shim's to adjust the Needle independently.
 
dirtdigger said:
Um you need to send pics of your carbs because non of the carbs have the needles adjustable like that. The round tops are adjusted with clip position and the keyholes are adjusted with shims under the needle clip. I think you are confusing adjusting the needle and adjusting the slide...the slide is adjusted with the nut and screw not the needles.

The pics of your plugs definitely dont look lean. Looks tan to brown and actually a little rich. The weirdness on the insulator looks like it could be oil usage in that cylinder.
Click to expand...
One Side is a Tan/Yellowish. And the Spot that appear's Rich in the Pick is not Carbon. It's Silver like Aluminum. Like somehow Aluminum got on the Plug.
 
JerrodR said:
One Side is a Tan/Yellowish. And the Spot that appear's Rich in the Pick is not Carbon. It's Silver like Aluminum. Like somehow Aluminum got on the Plug.
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I can't tell if the pics contain the plug you describe as having a silver spot. Such a spot could be detonation - the aluminum coming from the piston crown. Ignition timing too advanced, bad fuel or lean condition (lean misfire) can cause detonation. Those conditions can also cause some of the symptoms as hesitation, poor off idle, etc.
 
jpdevol said:
I can't tell if the pics contain the plug you describe as having a silver spot. Such a spot could be detonation - the aluminum coming from the piston crown. Ignition timing too advanced, bad fuel or lean condition (lean misfire) can cause detonation. Those conditions can also cause some of the symptoms as hesitation, poor off idle, etc.
Click to expand...

jpdevol said:
I can't tell if the pics contain the plug you describe as having a silver spot. Such a spot could be detonation - the aluminum coming from the piston crown. Ignition timing too advanced, bad fuel or lean condition (lean misfire) can cause detonation. Those conditions can also cause some of the symptoms as hesitation, poor off idle, etc.
Click to expand...
It's Lean. I took it out around My Neighborhood and after 3 or 4 Minute's it started overheating and Stalling out. I had to Run it on full Choke to get it Home.
 
JerrodR said:
It's Lean. I took it out around My Neighborhood and after 3 or 4 Minute's it started overheating and Stalling out. I had to Run it on full Choke to get it Home.
Click to expand...
But it would Run much better up over 4k RPM. This is where I get confused. When I was Running #125 Main's it Ran great under 4k, and if I tried to go over it would go lean and pretty much stall out..
 
JerrodR said:
But it would Run much better up over 4k RPM. This is where I get confused. When I was Running #125 Main's it Ran great under 4k, and if I tried to go over it would go lean and pretty much stall out..
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So with #125 Main Jet's I could Ride around all day as long as I stayed in the Pilot Jet but would Lean out when I got into the Main. So I went to #130 Main and it flips flopped and started Running Lean at Low RPM. It makes no sense.
 
Looks like I got it Guy's! Looks like it was the Pilot Screw's. The Screw's on My XJ add's More Fuel and that's how I set the CB's Screw's But Their actually Opposite They add more Air. So I Reset them a 3/4 of a Turn and it changed everything.
 
Yep the XJ has fuel screws the CB has air screws👍

If you continue to get silver specs on plugs, I'd be checking the timing and advance mechanism
 
dirtdigger said:
As I tell everyone, easiest and fastest way to jet is using the choke. When riding get to the trouble spot and hold the throttle, start closing the choke, if the engine picks up then its lean, if it stays about the same or bogs down its already too rich. These carbs are harder to jet because you have to use shims to change the needle position. Many people only try pilot and main jets which is a mistake. The needle jet has more affect of more of the throttle range than either of the fixed jets in the carb.
Click to expand...
Wow!! This site is a god send!!! Where would I get the “shims” u r talking about? All I’ve ever done is changed jets!!!
 

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