Author Topic: LTD - Mikuni Carb Tuning  (Read 6695 times)

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jskal

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LTD - Mikuni Carb Tuning
« on: September 17, 2014, 08:28:07 PM »
Found an 81 LTD in good shape.  Was running with the Keihn's, but converted to Mikuni 38's with some help from Tory.  Thanks for the Specs Tory!  It is close, but having trouble getting it dialed so I though I would post to the group.

The motor fires and runs, relatively crisp in 50 degree temps.  Idling right now at 3200-3500.  If I adjust idle down below 3000 I lose the crisp sound and start getting a bog.  Have mixture set at 1-3/4 (have tested from 1 to 2-1/2.  Pilots are 35's

Restart is miserable, warm or cold, and usually requires choke even after sitting for a few seconds.  All jetting components are brand new, including needle & seats.  Carb bodies are clean.  Carb boots are pliable with no visible cracks/tears.

Is this the infamous - Time-4-Seals?  Also planning to install UFO's, but would like to get it running/starting clean first. 

Checkmarks

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Re: LTD - Mikuni Carb Tuning
« Reply #1 on: September 18, 2014, 01:15:44 AM »
Just because you put in new pilot jets does not mean the pilot circuit is good.  The idle/pilot passage needs to be clean.  Sounds like this is where I would look for your troubles. 

Of course this is clearly after you changed the seals.  Until you do seals it would not matter how spotless your carburetors or passages can be cleaned.

You want to get it running/starting clean first??  During idle fuel is pulled only through the pilot circuit with a little air through carb.  If you have a air entering (seals, carb boots, extra hole drilled in thru crank cases)  this system anywhere other than thru the carburetor, then you motor will never idle worth a crud and be pig hard to start.

Tory944

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Re: LTD - Mikuni Carb Tuning
« Reply #2 on: September 18, 2014, 06:42:27 AM »
...  Agreed.  Is the poor response with the sled stationary (on a stand) or moving? Idle passage is (hole) at the bottom of the carb throat (where your filters mount).
Torys Vintage Sleds
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Tory944

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Re: LTD - Mikuni Carb Tuning
« Reply #3 on: September 18, 2014, 07:01:23 AM »
Check your PM.
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Website:  torysvintagesleds.com