cjcocn
Collector wannabe
Posts: 17 
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Post by cjcocn on Dec 7, 2009 22:42:55 GMT -5
Hi all
A buddy dropped off a 54 that wouldn't rev up. I cleaned the carb and want to adjust it back to factory as it appears that someone tried to deal with the problem by adjusting the L & H screws (the L screw was almost falling out!).
What are the initial settings for the H & L screws?
While I am at it, what are the upper and lower RPM ranges?
Also, I collect chainsaw documents and have seen a few posts mentioning service manuals (tried doing a search on the 54 and read this in the results). Does anyone want to trade pdf files?
Thanks
Chris
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Post by chainsawwhisperer on Dec 8, 2009 5:40:04 GMT -5
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cjcocn
Collector wannabe
Posts: 17
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Post by cjcocn on Dec 8, 2009 6:29:15 GMT -5
That helps a ton! I did not know that they are essentially the Solo 654. I have some service info on the 654 so I am all set. Thanks a bunch for your help.  |
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Post by MCS on Dec 8, 2009 11:24:50 GMT -5
Carb adjustment on most all position carburetors is pretty much the same. If the carb has both high and low adjustments, set them both at one turn open. Turn the idle speed screw until you actually see the shaft open a little. The saw should run and idle. Here is where you may have to make a few tweaks based on how the saw responded to the initial settings. Now let the saw warm up for a few minutes. The high speed circuit can affect the idle. You have to spend some time reading about the theory to understand this. There are three conditions to have to be met: - The saw must idle below clutch engagement.
- The saw should rev up to high RPM and then start missing. Leaning down the high speed should make the missing go away but we don't want to leave it like this. We want it to miss a little.
- The saw should accelerate without too much delay or hesitation.
Final settings: I usually set the high speed first. Run the saw up to full throttle and listen. If you hear the miss, lean it down until it runs smooth then open up the high speed until you hear the miss. Usually about 1/8 to 1/4 turn. If you don't hear the miss, open the high speed until you do. If you don't hear the miss at 1 3/4 turns open, something is wrong. Adjust the low speed to obtain max idle speed then turn down the speed below clutch engagement. Repeat. Once you reach the ideal point, turn the low speed open 1/8 turn. This helps with acceleration. Test acceleration. If there is serious hesitation, try opening the low speed then the high speed. Every saw is a little different so this is where experience and practice come into play. In a correctly working carburetor: The saw should die as you turn the low speed closed. I've seen saws idle with the low speed closed which usually means the needle point or seat is damaged. The high speed should make the saw run at max RPM with no missing and then cause missing as it is opened. If either mixture screw has to be set greater than 2 turns open, something is wrong. Crank seals and read valve can cause hard to diagnose problems. The ignition system could be causing the miss at high RPMs that is why it is important to understand what should happen when the carburetor adjustment screws are turned. Have fun................. |
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Post by aviatur on Dec 8, 2009 23:01:08 GMT -5
That is a very good explanation of carb setting. It's pretty much how I do it, but you explaned it very well! |
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