More Data on carbs. Capt,n

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<!Message Starts Here><table border="0" cellspacing="0" cellpadding="0" width="98%"> <tbody> <tr> <td align="center"> <table border="0" cellspacing="1" cellpadding="0" width="100%"> <tbody> <tr> <td align="center"> <table border="0" cellspacing="0" cellpadding="2" width="100%"> <tbody> <tr> <td class="info" valign="top" colspan="2" align="left">captinjohn -&gt; Inside the Tillotson Carb DLE30 (7/27/2010 11:59 PM)</td> </tr> <tr> <td valign="top" colspan="2">
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I did some reading and took apart the Carb on my DLE30cc engine. I wanted to first make sure it was clean &amp; parts in good order. I found there was marks on the 3 sides of the fuel shut off that has a neoprene tip. The 3 sides are metal. I honed them smooth with a fine hone stone. Blew out all passage ways. Checked the inlet screen...it was pretty clean. I decided to do a cut on the throttle butterfly, like I read about doing. I used a small carbide cutter in my dremel and cut the small moon on the edge of plate about 20% bigger to let in more air on Idle...I knew I would have to learn new carb needle settings.

Well after much trouble putting the small spring in place under the pivot arm...I got it all together wetting it as I put it together. It was a" buger" to get the needles right to get running...but when I did it sure runs better ...as with ...it seems to have taken out that rich burble at part throttle. I do not advise anyone to try this....unless you got extra parts you may wreck so you can replace them!!! Some photos below. Note: the moon on edge of throttle plate is bigger now. Spring length unchanger.... .445 on dial indicator. Capt,n</p> </span></td> </tr> <tr> <td class="info" valign="bottom" colspan="2" nowrap="nowrap">
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<hr width="98%" />
<table border="0" cellspacing="0" cellpadding="0" width="98%"> <tbody> <tr> <td align="center"> <table border="0" cellspacing="1" cellpadding="0" width="100%"> <tbody> <tr> <td align="center"> <table border="0" cellspacing="0" cellpadding="2" width="100%"> <tbody> <tr> <td class="info" valign="top" colspan="2" align="left">captinjohn -&gt; RE: Inside the Tillotson Carb DLE30 (7/28/2010 12:15 AM)</td> </tr> <tr> <td valign="top" colspan="2">
<span class="msg"><font size="2">Read this before you try this. Please as this thread for now goes on, do not ask to much....read first or if you have done this or know more about this please add to the good data. Asking is best to do after reading or trying it for yourself. It does work. Best Regards Capt,n <hr /> </font>

<u>IMPORTANT:</u> Wherever the idle pickup holes are in your carb throat, make the plate notch in front -or aligned- to them, and make sure you do not grind any more than 2mm. If you grind away too much, the engine will simply have a fast uncontrolled idle that cannot be adjusted with the idle stop screw or the Low speed needle (buy a $0.79 cent spare butterfly plate just in case: Throttle Valve, Walbro # 34-305); For Walbro distributors in your country or state click HERE.</p>

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When you place the throttle flap back, ensure it closes completely before tightening it to its shaft, and don't push too hard while tightening it or you will bend the delicate brass shaft. Add one small drop of LockTite to its central screw. Mount the carb on the engine and make sure the throttle cable permits the complete throttle assembly to open and return &ldquo;all the way&rdquo; against the stop! With this done you will now open the Low speed needle 1 turn (WG8); [WB series: Open the Low speed needle 1 turn and open the High speed needle 1/2 turn to start out] and back out that mashed idle stop screw to where it's supposed to be: about half way out.</p>

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Again, check that the complete throttle assembly works correctly and the throttle flap closes completely and freely. Also test the choke mechanism for free movement. Start your engine and <u>allow it to warm up</u> at low/mid RPM.</p>

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High Speed Neddle Adjustment
If you have a WB series carb, next make a high speed run and adjust your High speed needle at high RPM. The ideal high speed mixture is the richest setting that still permits strong acceleration up to peak RPM. With this in mind, it is always wise to start out slightly over rich and slowly lean the mixture out. If the high speed mixture is too lean, you'll experience weak or "lazy" mid range acceleration. You'll eventually find a narrow adjustment range where peak rpm operation seems unchanged. However, within this range, there should be a noticeable difference in mid to high range acceleration. Finding the setting within this range that gives the best "middle through high range a cceleration" usually requires patience to train your hearing..acceleration" usually requires patience to train your hearing .
</p> <div>Idle Adjustment
Once the engine is operating at normal temperature, you can now adjust the idle stop screw till you achieve a smooth idle.

</p> <u>What did all this achieve?</u>
You now allowed enough airflow for the engine to run properly at idle. You allowed for a smooth controlled idle since the Low speed mixture is finally balanced.

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