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Philip Croff
Member
Username: F14crazy
Post Number: 31
Registered: 05-2005
Posted From: 24.56.201.68
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, October 01, 2005 - 04:58 pm: | 
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Howdy. In a few other posts I've mentioned that I wanted to convert my early Sachs 277 Amphicat to a better motor. We've had problems with the old Sachs. I want/need more consistent performance. Getting screwed in the woods wouldbe screwed (normally don't go alone but it's a lot to tow with a quad).
I picked a good, used Honda GX390. 4 stroke, horizontal shaft, single cylinder, 13 horsepower. Picked up from ebay. $280 some total for it. Found out that it was intended for a generator and had an odd 22.2mm shaft. Nobody had or made a V belt clutch for it (called Comet, searched internet, asked Richard Clark). So, I decided to visit a local snowmobile dealer and got me a new Comet Duster 94c 30mm "universal" clutch. Had Backdoor Machining in Lansing adapt the clutch up to the goofy shaft. I still don't understand how he did it, but it seems to be perfectly fine.
Removed the old Sachs motor (I'm willing to sell it). Using some 1/4''x2.5'' steel and the existing rubber mounts, my brother and I got the Honda mounted in place. Using the existing 1'' belt for now, though the Comet calls for a 1 3/8'' or something like that. He got the throttle linkage setup and I messed with fuel delivery. Part of the plastic and steel crossmember in the rear of the Amphicat had to be removed. Will need to make a new hood or cut up the other one.
We've almost got it running. It was flooding at first but it's not running well (not steady). Since we're tired out, I'm going to clean out the carb (again) tomorrow because we figure that maybe some crap got stuck in it when we purged the fuel lines of air. But oh well. In the short time we had it running well we watched the clutch operate and it seems to be fine. Honda's RPMs are 1400-3900 and Comet says the clutch engages at 3100. This made me think that it would engage too late, but it seems to be fine for the time being. The dealer said that I can change the springs and stuff in the clutch and get it to engage earlier if needed, but for now, it's okay.
I've taken a lot of photos of this project, of which I'll try to get to uploading to my FTP space later today and post here.
I went with the Honda because I know that it will last a long time, won't have dumb little problems, and will consistantly perform without problems. The old Sachs randomly quit on me a few times. kept having carburation problems. Loud. Smoky. And will foul plugs. I probably should have waited for an electric start Honda (mine doesn't have e/s) but hey, I'm 17 and Honda's normally pull on the second, if not first pull. I don't normally ride at night but I'll rig up a battery or something to run lights if the engines magneto doesn't produce enough surplus current. We did bench test the new motor. It's going to be smooth and quiet. Both my dad and I were against buying a BS motor because we haven't had good luck with them (I don't like things like starter ropes breaking and snapping back on my hand).
I'm posting since at least one member requested that I do because he wanted to also convert his Terra Tiger to modern propulsion. I'm asking my friends and family to pick me up some nice plastic emblems on ebay with "powered by Honda" to go beside the Amphicat logo |
Philip Croff
Member
Username: F14crazy
Post Number: 32
Registered: 05-2005
Posted From: 24.56.201.68
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 03, 2005 - 05:00 pm: |
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Well folks, I took the carb apart again and blew it out with compressed air, and the Honda's running great. I need to go to a wider belt and probably change stuff in the clutch because it's engaging a bit too late (like 80% throttle results in a fast walk). But I'd say it's a success. Here's all 11 photos of the mess from my FTP server.
http://members.aol.com/f14crazy/honda1.jpg
Powered by Honda!
http://members.aol.com/f14crazy/honda2.jpg
The ancient Sachs 277. I'm willing to sell it to anyone interested.
http://members.aol.com/f14crazy/honda1.jpg
The big hole, soon to be occupied by the Honda
http://members.aol.com/f14crazy/honda4.jpg
I sat the Honda in the engine bay and measure how much I needed to cut out because this motor has more "stuff" farther back. I had to cut it a little wider but this is about it.
http://members.aol.com/f14crazy/honda5.jpg
Sitting where it should be, and measuring to make our mounts.
http://members.aol.com/f14crazy/honda6.jpg
Another view, showing the Comet Duster 94c clutch.
http://members.aol.com/f14crazy/honda7.jpg
A crappy photo (all taken with my Palm Treo 600) but showing how the mounts are on the engine. It's 1/4''x2.75'' (or so) flat stock steel I picked up from the "usables" lot at the Padnos scrap yard in Lansing.
http://members.aol.com/f14crazy/honda8.jpg
Sorry for another poor quality photo, but this shows the Honda's stock exhaust. We're running 3/4'' copper out of the stock muffler and out the back (we're plumbers). Thinking about having an upright stack and air cleaner
http://members.aol.com/f14crazy/honda9.jpg
Closeup of the clutch. It's a 30mm shaft universal snowmobile clutch. Was about $225 from Groves Motorsports in Mason (think it was the parts unlimited catalog, or wagner, or something like that).
http://members.aol.com/f14crazy/honda10.jpg
It's done and moving itself! I've thought that Amphicats are a bit better looking than most AATVs. Max's are just ugly, and Argo's look like frogs (just messin, I wouldn't mind a modern AATV of any brand)
http://members.aol.com/f14crazy/honda11.jpg
Front shot. |
Derek Hubbard
Junior Member
Username: Justmax
Post Number: 15
Registered: 02-2005
Posted From: 24.166.114.118
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 03, 2005 - 10:23 pm: |
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Mr Croff:
How does the Amphicat runs with the 13 hp honda in it? I have one to fix up , but the lite weight body is a total basket case. Too many holes and crush sections to fix. Your looks real good with the original flotation tires on it. Some questions on the transmission. How does it work and does it have a reverse gear? I have a Max 2 that I am working on now, so thats my main goal, but the amphicat maybe next on the work bench.
Derek
justmax |
Philip Croff
Member
Username: F14crazy
Post Number: 34
Registered: 05-2005
Posted From: 24.56.201.68
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 04, 2005 - 08:28 pm: |
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The Amphicat currently moves at a fast walk at WOT. We're going to upgrade to a wider belt; the stock one is 1'' and the clutch needs like 1 3/8'' or something like that. The motor has to spin up the clutch fast, before it touches the belt, although it's moving. And it's engaging at too high RPM. We've anticipated this and I'm going to talk to the motorsports shop dude on what I should change (springs, pucks, etc). I have a couple spare tires that are holding air.
This tranny has oil lubed clutches and brakes inside. And it does have reverse by pressing/stepping on a U shaped lever by your heels. There were a few different Amphicats but mine's the first edition. |
Derek Hubbard
Junior Member
Username: Justmax
Post Number: 16
Registered: 02-2005
Posted From: 24.166.114.118
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 04, 2005 - 09:47 pm: |
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Thanks Philip:
My transmission looks like yours so that is good to know on how it works. I saw a 74' Argo with three bolts rims on Ebay. Have anybody seen or heard of these type rims? They bolt straight to the axle without an adapter. They look like good replacements for amphicats after the flotation tires bite the dust.
Derek |
Philip Croff
Member
Username: F14crazy
Post Number: 35
Registered: 05-2005
Posted From: 24.56.201.68
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 04, 2005 - 10:25 pm: |
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Yeah these tires won't last forever. A few of them were leaking around the base of the valve stem but Fix a Flat seems to be holding them fine. I have a couple spares for myself. It sucks that because of the valve stem in the hub, you can't use a left tire on the right, or the other way around.
Feel free to ask more questions |
Philip Croff
Member
Username: F14crazy
Post Number: 46
Registered: 05-2005
Posted From: 24.56.201.68
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, November 06, 2005 - 01:00 pm: |
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I haven't had much time in a while to work on it but I did this weekend.
My motor/clutch was not inline with the secondary clutch/pulley, so I had to make rectangular holes in my mounts (tedious). But it now lines up fine.
I'm now using a wider snowmobile belt since the Comet requires it. With the original Amphicat belt the engine had to spool up a lot more before the clutch even came in contact with the belt. I'm still using the original secondary clutch. To accomodate the wider belt, I pryed it open and inserted a 3 nuts (5/8'' head, I think). And a few zip ties around them so they won't ever fly out (they're held in by the extreme squishing force of the clutch anyway).
Speed is a lot better than it was but not as fast as it used to be. I know speed isn't a major thing with 6 wheelers but I need it for when I have to travel distances. I'm soon going to order the proper clutch parts for the 94c so that it will engage at like 1800rpm (motor is supposed to idle at 1400).
haven't figured out seats yet. I might be able to cut up and use the original hood. Instead of the bench I'd like to use a pair of generic replacement John Deere type seats (the yellow ones). They'll be a lot softer when hitting rough stuff and have a higher back to avoid whiplashing my back.
This winter I hope to be able to put the tracks on and go ride on the Grand River (if we have a winter where it'll freeze over) |
andrew thornton
New member
Username: Minzwa
Post Number: 1
Registered: 04-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 11, 2013 - 04:47 pm: |
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Hi all!
I am trying to get a 70's argo running properly and am dealing with a bit of a "frankensteins argo". This one has a Comet Duster clutch as well, and the belt measures 1 and 3/16 wide. Im having kinda the opposite problem of Jonny. The belt never stops turning, and doesn't seem to be touching the clutch shaft. There isn't any clearance at all on the sides of the belt (when motor is off). Because of this, I can't shift gears (the shifter works fine when the motor is off, but grinds when the motor is running because it is always spinning the driven. Don't worry, i haven't forced it at all, i understand it needs to be not spinning to be safe.
My question is, do i go with a narrower belt so that it stays still at idle speeds? Does not seem seat at the bottom of the clutch. Should it?
btw, when in neutral, as throttle is applied, the clutch spins and the belt moves out as expected, so the clutch seems to be working properly.
I live in Bend Oregon, & the nearest Argo dealer is hundreds of miles from here. Besides....frankenstein.  |
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