OLD zenoah 35(38?)
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OLD zenoah 35(38?)
Hey all I have a very old Zenoah 35, think this is the model that was before the 38. Any way I have had this engine for manyt many happy years of flying. After a year off from RC, getting everything ship shape again for flying.
got a problem. Redid all the fuel lines and made sure they were right and tight. Reinstalled tank. Tried to fire up engine. No go. Does not seem that the gas is getting sucked into carb. When I prime the carb, the engine starts on the first release of the spring starter. Runs until fuel in carb is gone. Took off carb and looked at gasket btw carb and engine. HELL IF I KNOW WHAT TO LOOK FOR! Is there a way to tell if the gasket is bad and needs replacing?
What would you do to pin down exactly is wrong with this motor? Appreciate any help offered.
got a problem. Redid all the fuel lines and made sure they were right and tight. Reinstalled tank. Tried to fire up engine. No go. Does not seem that the gas is getting sucked into carb. When I prime the carb, the engine starts on the first release of the spring starter. Runs until fuel in carb is gone. Took off carb and looked at gasket btw carb and engine. HELL IF I KNOW WHAT TO LOOK FOR! Is there a way to tell if the gasket is bad and needs replacing?
What would you do to pin down exactly is wrong with this motor? Appreciate any help offered.
#2
RE: OLD zenoah 35(38?)
Sounds like it's only running long enough to burn off the prime, which could mean that the carb is not pumping or there is some debris blocking the carb's internal filter screen. It might be time for a well needed carb clean including a repair kit and new diaphram.
Karol
Karol
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RE: OLD zenoah 35(38?)
Thanks. Now looking for parts and all, I am beginning to wonder. Did zenoah ever make a 35cc or could this be a Quadra? I know Quadra used to make a 35cc, but I cant find any info on a zenoah 35cc. MMmmmm CRUD!!!
A carb rebuild kit should not really matter much I think. How can I tell if the carb insulator gaskets are ok? Could this be the problem. Just trying the easy route before having to rebuild a carb, which I have never done.
A carb rebuild kit should not really matter much I think. How can I tell if the carb insulator gaskets are ok? Could this be the problem. Just trying the easy route before having to rebuild a carb, which I have never done.
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RE: OLD zenoah 35(38?)
There should be a number on the carb engine make won't matter. If you are not comfortable a local small engine shop will rebuild and basic set the needles for you. You will still have to fine tune but it will get the engine running. Not an expensive item
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RE: OLD zenoah 35(38?)
The diaphragm is likely stiff and unable to pump the fuel...and though that may be the only thing holding you up, with the carb partially apart, it would make good sense to visually inspect and clean the filter screen, and give it a good cleaning inside and out. If you plan to have your local mower shop do this for you, make note of where your carb needles are currently set before handing it over, so you have a ballpark idea of where things might end up when you re-tune. don't expect that they will be in the same position after a good cleaning and a replacement part or two when you retune it, but it would be good to have an 'idea'.
Chad
Chad
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RE: OLD zenoah 35(38?)
Thanks. I did note that when I took the carb off the engine to take a look see, it was not attached very tightly. Could the gasket from the carb to the engine been leaking and this causing the no fuel draw situation?
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RE: OLD zenoah 35(38?)
Yes, there is a pulse port in the cyl case, carb block and gaskets, that allows case pressure to 'pulse' through to the carb and diaphragm to meter the fuel. If the pulse goes anywhere but through the port properly, and without leaking, it could weaken or not even be present, preventing the correct metering, or pumping of fuel once running. This could explain why after choking it will run briefly, but nothing beyond that.
Chad
Chad
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RE: OLD zenoah 35(38?)
Seriously though....once you are monkeying with it at all, it would be well worth your time to tidy things up, and at the least, replace the diaphragm. Then you can look forward to some significant run time before further attention is required.
Chad
Chad
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RE: OLD zenoah 35(38?)
Haha....I understand how intimidating a carb rebuild might sound, when you haven't done it. But you have to trust us here, and know that it is not a big deal, and certainly not worth shipping it off somewhere to have it done. your local outdoor power equipment shop can easily get you the parts, either with the carb in hand, or the number off of it, and they can even rebuild it for you without extensive cost or time involved at all. No worries man!
Chad
Chad
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RE: OLD zenoah 35(38?)
http://wem.walbro.com/distributors/servicemanuals/
or type in the walbro part number in the upper right on this page:
http://wem.walbro.com/walbro/family.asp
(I'm guessing that it is a walbro) You will find the number stamped right onto the carb...
Chad
or type in the walbro part number in the upper right on this page:
http://wem.walbro.com/walbro/family.asp
(I'm guessing that it is a walbro) You will find the number stamped right onto the carb...
Chad
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RE: OLD zenoah 35(38?)
www.bennettbuilt.com is also a good source for Quadra and Zenoah parts and service items I would be surprised if Dick doesn't have carb kits as well.
Chad
Chad