Small Engines (Lawn Mowers, etc.): Leaf blower won t start or even try, paper gaskets, weed eater

Question
Update: Regarding compression, I have these two identical (though different branded) problem blowers, and a 3rd Weed Eater blower that starts right up.  This allows me to make comparisons, check spark plugs definitively, etc.  I am now focused on the Weed Eater that won t start.  I compared compression amongst all of these, and they re all similar: 50-65psi by one gauge; 100-110psi by the other.  Since the good blower has similar compression, it makes me think that low compression isn t the issue. (By the way, this blower is older--1997--and has a larger, 32cc engine.)  What is considered normal compression?      None of these has an obvious oil leak, and I was thinking that the carb is the more likely culprit. So, I tried an experiment: I switched carbs from the identical Craftsman and Weed Eater blowers.  I was still able to start the Craftsman, and still unable to start the Weed Eater, so that rules out the carb as the problem.  Regarding your admonition to ensure that the pulse holes are aligned, these carbs have no paper gaskets; they mount right onto a plastic piece mounted on the engine intake, and the choke side just has the plastic carb housing screwed onto it. So when you mention an intake gasket, I don t know whether you re referring to an internal gasket, or an external gasket which doesn t exist on these blowers.    These blowers don t have a rear engine housing; the plastic housing is split into right and left sides.  I took one apart a while back, and as I recall, it was a real hassle to reassemble, so I am resistant to doing this, unless I m convinced that it is necessary (or there is no other option).  Considering the similar compression of all 3 units--2 of which run, one of which starts easily--and that there is no obvious oil leak, is checking this seal necessary?  Also, I m unclear as to whether you are recommending that I remove and use silicone on it regardless of whether there is evidence of a leak if I inspect it.    Thanks, Scott

Answer
There are tools to perform leak down tests to check for an air leak.  If swapping the carbs made no difference, then the problem must be compression or a crankcase leak.

That it the only problem that would cause them not to start.  You can remove the muffler and try to start them to ensure the engine is breathing.

If you go to the Sears website, look under parts, input your model number you can see a parts breakdown.  Check to see if there is an intake gasket, external, between the carb and the plastic carb intake mount.  If that part warps, with no gaskets, there will be an air leak causing the carb not to work.

Let me know.
Eric