carbtune question

[Boriqua]

I have used the morgan carbtune pro twice or three times before. It was easy enough. I have since made some adjustments to my carbs and it was feeling lumpy so I decided I would take a look at the sync.

Problem was the carbtune wouldnt register anything below say 3500 rpm. I am so sure I didnt sync them last time at 4000 rpm. At 1500-2500 the metal rods stayed firmly at the bottom. Not sure what would cause that?

Vacuum line was plugged and I dont have any leaks.

My plugs look great the bike runs awesome but I cannot nail this idle. At first it needs choke for about 2 miles and will stall out if I let it at lights until I have about 5 miles. I tweak the throttle some to make sure it doesnt stall. Then it will idle at 1200 pretty nicely but once it gets good and hot when I pull up to a light it will hang at 2000 for up to 20-30 seconds and then drop down to 1200.

I figured it taking that long to warm up and needing choke so long that it maybe needed to be a bit richer so I turned the screw up 1/4 turn. I am now at 3 1/4 turns on each screw.

Like i said .. bike runs good and strong ... I just cant nail the idle. I may have to admit defeat and see if I can find a local mechanic

 

[Steve]

Don’t be afraid to go another 1/4 turn. Tune each carb individually, they won’t necessarily all be the same.

When the rods won’t move off the bottom, turn the gauge over, so the vacuum now pulls the rods DOWN, against their springs. I learned that trick by reading the directions. :encouragement:

.

 

[eil]

Do you have new carb boots? Hanging idle is a classic symptom of a vacuum leak.

 

[Boriqua]

alrighty steve ... I felt like an idiot so I went and reread the instructions and Problems FAQ but I dont find anything about using the gauge upside down.

https://www.carbtune.com/inst.html

https://www.carbtune.com/carbfaqs.html

So I will ask since you are one of the carb heros here.... Are you suggesting holding it upside down to use or just turning it upside down and then back to right side up. They have Maintenance instructions that involve inverting but I just cant find instruction on using it if the rods don't rise.

I have my weird idle squared away, bike runs well but I know it is in need of a sync to get it perfect.

When I was a kid they had a program called RIF. Reading is fundamental .. maybe it failed me!

 

[hannibal]

No you hang it upside down and sync with it in that position.

 

[Guest]

alrighty steve ... I felt like an idiot so I went and reread the instructions and Problems FAQ but I dont find anything about using the gauge upside down.

https://www.carbtune.com/inst.html

At the top of the page, under 'Description', fourth paragraph down:

To get a reading below 8cmHg remove the plastic cable clip from the slot at top of gauge and insert it into the slot at the bottom. Push cable clip into slot from front of gauge. Hang the Carbtune Pro upside-down.
Ignore the scale figures. Zero will now be around 16cmHg on the scale but the full width scale graduations will still be 2cmHg. Absolute values are not important. Comparisons are important.

Mark

 

[Steve]

alrighty steve ... I felt like an idiot so I went and reread the instructions and Problems FAQ but I dont find anything about using the gauge upside down.

https://www.carbtune.com/inst.html

https://www.carbtune.com/carbfaqs.html

So I will ask since you are one of the carb heros here.... Are you suggesting holding it upside down to use or just turning it upside down and then back to right side up. They have Maintenance instructions that involve inverting but I just cant find instruction on using it if the rods don't rise.

No you hang it upside down and sync with it in that position.

At the top of the page, under 'Description', fourth paragraph down:
Mark

Thank you, hannibal and Mark. :encouragement:

.

 

[Boriqua]

Thank you EVERYONE! I dont know how i missed that ... several times ... but it will come in handy because saturday is sync day. I didnt even know there was a hanger slot on the bottom?!

I am sure I cant have been the only person that ran into this .. maybe .. so its good info to have up here for future searches.
Alex

 

[Steve]

"Searches"??? You can SEARCH on this forum???

What will they think of next? :-\\\



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