Zenoah 22.5 from RedMax Recipacator
02-27-2005, 01:37 PM
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Zenoah 22.5 from RedMax Recipacator
Hey Zenoah experts
The subject engine came with a Walbro WT-458 Carb. (7.94mm venturi). Is this carb. good or can I get more performance with a larger venturi? If yes, what size venturi is recommended? What other (non machine shop) type mods can be made to this engine to improve performance.
Sides7
p.s. Ralph, on that 25.4cc engine you fixed, can you tell me what is acceptable for the compression ?
The subject engine came with a Walbro WT-458 Carb. (7.94mm venturi). Is this carb. good or can I get more performance with a larger venturi? If yes, what size venturi is recommended? What other (non machine shop) type mods can be made to this engine to improve performance.
Sides7
p.s. Ralph, on that 25.4cc engine you fixed, can you tell me what is acceptable for the compression ?
02-27-2005, 02:53 PM
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RE: Zenoah 22.5 from RedMax Recipacator
Lost my compression tester, the compression on a G62 when flipping by hand usually runs around 120 psi in a dry cylinder, about 150 if you put some oil in it first...My chainsaw book says below 90 on a chainsaw is time for new rings...[8D]
a 7.94 carb is a little small, if you can find an 11mm it might run better..Early G23s ran a WA125, 9.53mm.....Anything over that doesn't make much difference...Later ones ran a WA167, 11.1mm....New 23 helicopter engines run a WT 643, 12.7mm...they're set to turn between 9000 and 10,500 by varying the rotor pitch....
Where in Marana do all these Red Max things come from ?
a 7.94 carb is a little small, if you can find an 11mm it might run better..Early G23s ran a WA125, 9.53mm.....Anything over that doesn't make much difference...Later ones ran a WA167, 11.1mm....New 23 helicopter engines run a WT 643, 12.7mm...they're set to turn between 9000 and 10,500 by varying the rotor pitch....
Where in Marana do all these Red Max things come from ?
02-27-2005, 04:18 PM
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RE: Zenoah 22.5 from RedMax Recipacator
Ralph
I was hoping you would respond. My main source for the RedMax lawn maintenance equipment is the Golf Course Greens Keeper responsible for total maintenance of my home course. My home is on the 8th fairway. I'm in the process of getting the Greens Keeper & his son started into the RC hobby. He's agreed to pass off to me any 2 cycle items that would otherwise go to the junk pile. I'm got several John Deere items (Homelite) & a few Redmax from him. Hope he stays interested in RC.
Thanks for the info Ralph - I'm trying to dig-up a compression tester to checkout that 25.4cc job. Anything else you can suggest to improve the performance?
Sides7
I was hoping you would respond. My main source for the RedMax lawn maintenance equipment is the Golf Course Greens Keeper responsible for total maintenance of my home course. My home is on the 8th fairway. I'm in the process of getting the Greens Keeper & his son started into the RC hobby. He's agreed to pass off to me any 2 cycle items that would otherwise go to the junk pile. I'm got several John Deere items (Homelite) & a few Redmax from him. Hope he stays interested in RC.
Thanks for the info Ralph - I'm trying to dig-up a compression tester to checkout that 25.4cc job. Anything else you can suggest to improve the performance?
Sides7
02-27-2005, 04:41 PM
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RE: Zenoah 22.5 from RedMax Recipacator
You might check the distance from the top of the piston to the top of the combustion chamber, about .020 is best for performance...A thin base gasket might do..That engine is made for reduced emissions, so maybe it's as good as it gets...Be careful of that cut down flywheel......Yours is the first I've seen with the funny carb and transfer ports...I have a Homelite here that's made like that but haven't had time to check it out...[8D]
The desert down there must be getting overgrown from all the rain, how's the yellow flowers around Picacho Peak this year ?
The desert down there must be getting overgrown from all the rain, how's the yellow flowers around Picacho Peak this year ?
02-27-2005, 04:59 PM
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RE: Zenoah 22.5 from RedMax Recipacator
Thanks again for the info. The wild flowers this year are going to be unbelievealbe. They have already started but should peak in about two weeks. There are always negatives & positives with all this rain - that is, so much undergrowth makes for lots of potential fires next burn season. For now, just have to enjoy - will be going to Picacho Peak before too long to take it all in.
I've got a 41.5cc Zenoah from Redmax Blower running with the stock carb (WYK-67, 13.5 mm venturi, rotary valve type) turning a MAS 18x8 @ almost 9000 rpm. Planning to change to a standard carb.(HDA 112-A) from a chain saw, also 13.5mm, as no needles on the stock one.
Probably will try a 20X8. Sound OK to you?
Sides7
p.s. Need a prop adapter for the 22.5cc Zenoah. Ralph, can you make one for me?
Sides7
I've got a 41.5cc Zenoah from Redmax Blower running with the stock carb (WYK-67, 13.5 mm venturi, rotary valve type) turning a MAS 18x8 @ almost 9000 rpm. Planning to change to a standard carb.(HDA 112-A) from a chain saw, also 13.5mm, as no needles on the stock one.
Probably will try a 20X8. Sound OK to you?
Sides7
p.s. Need a prop adapter for the 22.5cc Zenoah. Ralph, can you make one for me?
Sides7
02-27-2005, 07:46 PM
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RE: Zenoah 22.5 from RedMax Recipacator
I made (and sold) a few 42cc Zenoahs from the Red Max BC430 brushcutter...I used a 20-10 Zinger, don't remember the rpm, but it worked great...I had it on a scratch built plane called a Prime Cut, one of my favorite planes...Met an unfortunate demise, hit the steel I beam frame of the club water hauling trailer...[&o]
It was the smoothest single I had ever tested, same size crank as a G62....
It was the smoothest single I had ever tested, same size crank as a G62....
03-02-2005, 08:25 PM
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RE: Zenoah 22.5 from RedMax Recipacator
Got the Zenoah 42cc running with the new chain saw carb. & a Zinger 20x10 prop. It seemed to peak @ 6800 rpm. Does this sound about right? The strange thing is that the engine seems to peak at about 1/2 turn open on the high needle and doesn't seem to change from there all the way closed,ie still at 6800 rpm with the high needle all the way screwed shut. Any comments? Realible idle was about 2100 rpm.
Sides7
P.S. Ralph, a guy here has a Prime Cut kit up for sale. Got time to take on that project?
Sides7
P.S. Ralph, a guy here has a Prime Cut kit up for sale. Got time to take on that project?
03-02-2005, 10:10 PM
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RE: Zenoah 22.5 from RedMax Recipacator
If it runs with the high needle closed the low needle is open too far..
Rpm sounds good for that engine, mine ran about the same..
No time to build planes, too many engines...
I just bought a flyable bipe with a G62 from a friend, now I can fly at the CAM May fly...It's a great event, Sedona is not that far from Marana, maybe see you there.?...
Rpm sounds good for that engine, mine ran about the same..
No time to build planes, too many engines...
I just bought a flyable bipe with a G62 from a friend, now I can fly at the CAM May fly...It's a great event, Sedona is not that far from Marana, maybe see you there.?...
03-02-2005, 10:52 PM
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RE: Zenoah 22.5 from RedMax Recipacator
Jim
Redmax sells these and they look like a weedie with a circular saw blade instead of the string trimmer. If you look at the Redmax web site (www.redmax.com) at their products, you'll see a picture.
Ralph
Glad to hear you say I'm about right on the performance on that 42cc engine. I'll say one thing, with that 20x10 it pulls like crazy. I'll do some more work on the needles & see if I can set things right. Would love to make it to the fly-in in Sedona. I snowbird back to the state of WA. about mid-May. When is the fly-in?
Sides7
Redmax sells these and they look like a weedie with a circular saw blade instead of the string trimmer. If you look at the Redmax web site (www.redmax.com) at their products, you'll see a picture.
Ralph
Glad to hear you say I'm about right on the performance on that 42cc engine. I'll say one thing, with that 20x10 it pulls like crazy. I'll do some more work on the needles & see if I can set things right. Would love to make it to the fly-in in Sedona. I snowbird back to the state of WA. about mid-May. When is the fly-in?
Sides7
03-03-2005, 12:38 PM
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RE: Zenoah 22.5 from RedMax Recipacator
Redmax sells these and they look like a weedie with a circular saw blade instead of the string trimmer. If you look at the Redmax web site (www.redmax.com) at their products, you'll see a picture.
03-13-2005, 01:21 PM
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RE: Zenoah 22.5 from RedMax Recipacator
How did this conversion end up? I have one of these engines that was given to me that came with a single needle barrel type carb (WY?). Is this engine worth flying / The redmax case says G2K.
03-13-2005, 06:34 PM
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RE: Zenoah 22.5 from RedMax Recipacator
Mad Scientist
Not sure which engine you are inqiuiring about? In this thread, we have talked about two different Zenoah engines from Redmax equipment: 22.5cc from Reciporcator & 41.5cc from backback blower. Haven't done anything with the 22.5cc , awaiting a prop hub before I can do any testing. The 41.5cc engine is a hummer. No improvement mods, except using a chain saw carb with two needles and a 13.5mm venturi (removed theWYK67 -Barrel type ,no needles). Its turning a Zinger 20x10 @ 6800rpm and idles at 2000 rpm. Its mounted in a SPAD, "Ultra SPAD Stick"and is quite responsive. It replaced the Ryobi 31cc, which flew like a big trainer.
The 22.5cc engine came with a carb - not original equipment. It's no wonder it wouldn't run, the carb pressure port didn't match the pressure hole location in the carb standoff. Will be mounting a 11.1mm carb when testing starts.
Sides7
Not sure which engine you are inqiuiring about? In this thread, we have talked about two different Zenoah engines from Redmax equipment: 22.5cc from Reciporcator & 41.5cc from backback blower. Haven't done anything with the 22.5cc , awaiting a prop hub before I can do any testing. The 41.5cc engine is a hummer. No improvement mods, except using a chain saw carb with two needles and a 13.5mm venturi (removed theWYK67 -Barrel type ,no needles). Its turning a Zinger 20x10 @ 6800rpm and idles at 2000 rpm. Its mounted in a SPAD, "Ultra SPAD Stick"and is quite responsive. It replaced the Ryobi 31cc, which flew like a big trainer.
The 22.5cc engine came with a carb - not original equipment. It's no wonder it wouldn't run, the carb pressure port didn't match the pressure hole location in the carb standoff. Will be mounting a 11.1mm carb when testing starts.
Sides7
03-14-2005, 06:29 PM
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RE: Zenoah 22.5 from RedMax Recipacator
I think I have the 22.5 engine which came from either a string trimmer or recipicator. The lower shaft was gone before I got it. I haven't stripped it down fully yet as I have been running it in the driveway to make sure the carb is completely clean before I put it in a plane.
