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4a084 125

Posted: Wed Mar 02, 2011 9:43 am
by scubersteve
Here you are! I was wondering where everyone went... Hopefully this site will be as active as the old one was.
Anyway, I finally got back on my 4a084 125 project after about 2 years off.
Apparrently I just missed the "Redneck Nationals" at my local dragstrip that included mower drag
racing. They are doing it again in Nov so now I'm motivated to get this thing finished.
This weekend I got the fenders and footrests mounted. I'm still working on a driveshaft and
where to put two batteries (or switch to a 12v starter)
Image

Re: 4a084 125

Posted: Wed Mar 02, 2011 1:18 pm
by J Hayes
Welcome back Steve ! :beer:
Things are picking back up to being closer to normal. if you can or have email for some missing in action let them know we are here.
need to find some of the guys that were most active in their pics / projects. and hopefully they still have them to re post.

Have to really give a big hand to those that has many hours of their personal time to the forum it this far.

Re: 4a084 125

Posted: Fri Mar 04, 2011 10:04 pm
by Dave C
dude u guys have no idea how many hours i been staring at code trying to make this forum better...... thank god for beer and coffee! lol but its fun i like it
working on the memberlist now... trying to make it more searchable... but i got bugs up the wazzooo!

Re: 4a084 125

Posted: Mon Mar 07, 2011 4:59 pm
by rbeem
From what I hear the 24v starter spins the 4a084 motor just fine on 12v although I've never done it.

Re: 4a084 125

Posted: Mon Mar 07, 2011 10:58 pm
by scubersteve
I have tried the 24v starter on 12v and it didn't work at all. I'm looking at the mazda starter conversion. Anyway...
I'm planning on building a foot control setup for my hydro with the 4a084. I have flipped the charge pump to accomodate the reverse rotation. The question is do I need to flip the carrier or can I just make my controls so the lever works in the opposite direction? Is a hydro equally fast in both directions? If I effectively use reverse for forward on my hydro do I get full speed? Do I really have to flip my carrier? So many questions...

Re: 4a084 125

Posted: Tue Mar 08, 2011 9:29 am
by Farmallgray
Steve,
I don't think you need to flip the carrier or change the linkage. I think all you need to do is flip the charge pump.

Re: 4a084 125

Posted: Wed Mar 09, 2011 2:32 am
by Jlaws
Scubersteve , without any changes the hydro control will work backwards , moving the hydro control forward will cause it to back up and vice versa .
I'm not real familiar with the 125 linkage but if you can figure out a way to change the control linkage to work backwards then you wouldn't have to flip the carrier . But im not sure that changing the control linkage will work even then though , because the reverse slot in the trunion plate is shorter than the forward slot and you probably won't be able to get enough forward speed and a scary fast backing up speed . :lol:
Good luck on your project and keep us posted.

Re: 4a084 125

Posted: Wed Mar 09, 2011 2:46 pm
by Trebor
ScuberSteve,

Here is a PDF saved from the old site that you will find useful.

Re: 4a084 125

Posted: Wed Mar 09, 2011 4:21 pm
by scubersteve
Thanks Trebor, I was looking for that. I knew I had seen it somewhere. :thumbsup:

Re: 4a084 125

Posted: Sat Mar 12, 2011 8:17 pm
by scubersteve
got my driveshaft put together, but the angle is pretty severe... about 25 degrees. What do you guys think? Workable or
not? In order to lower the engine anymore I would have to notch the heck out of the frame, and I would rather not.
driveshaft (Medium).jpg

Re: 4a084 125

Posted: Sat Mar 12, 2011 8:34 pm
by Farmallgray
Steve,
I would check with the u-joint manufacturer and see what is the maximum angle they recommend.

Re: 4a084 125

Posted: Sat Mar 12, 2011 9:21 pm
by ERIC-SMITH
steve,
a couple of years back when my father built his tricycle 129 we ran the same type of drive shaft because we lowered the rear end to level the tractor out, what we did was we tipped the front of the motor up and lowered the rear mounting bolts for the rearend a few fractions more then the front bolts which tiped the rear end back and made a much more inline drive shaft with out the hard bends at the u-jounts also we made a cross member and ran a pillow block bearing to make sure we didnt get any unwanted vibration

Re: 4a084 125

Posted: Sat Mar 12, 2011 9:55 pm
by Paul B
That's quite a bit of an angle, I wouldn't want that spinning around at 3600 RPM between my legs. What ever you end up doing, be sure the U joints are rated for the angle, the amount of hp of the engine, and the RPM it is turning. Some might say that "parts is parts", but when it comes to U joints, they are not all created equal.

Re: 4a084 125

Posted: Thu Mar 17, 2011 7:46 pm
by scubersteve
I installed my mazda starter today on my 84. I'm not clear on what modifications were supposed to be done to make it work. I just used a 10mm bolt threaded into the bottom ear and a 5/16 bolt and nut on the top ear to allow me to roll the drive deeper into the ring gear. It seems to work ok, little noisy maybe. At least now I don't have to contend with two batteries.

Re: 4a084 125

Posted: Thu Mar 17, 2011 8:19 pm
by Amigatec
The Military did make 24v batteries the size of a Lawn mower battery. I don't know how easy they are to find.

Re: 4a084 125

Posted: Thu Mar 17, 2011 8:31 pm
by Paul B
I have a 4A032 in an Original and tried one of the reworked Mazda starters on it, but was not satisfied with it. The gear mesh was not too good which made it very noisy when engaged. I found a stock 24 volt starter and use it with a single 12V Wal-Mart lawn and garden battery (335 CCA). As long as the battery is fully charged, it will more than last thru numerous engine starts at a weekend show. I realize your engine is bigger displacement wise, but give the 24V starter a try with a fully charged 12V battery, might work. A small size 12V car battery may work better for you than a L&G size battery.

Re: 4a084 125

Posted: Sun Jul 24, 2011 6:56 pm
by scubersteve
I finally got around to addressing my driveshaft angle problem. I rolled the rear end up 4
degrees and the engine down 4. Now instead of a 25 degree angle, my drivshaft runs at 10
degrees. Compare this pic with the earlier one. I think it should be fine, what do you guys think?
Image

Re: 4a084 125

Posted: Mon Jul 25, 2011 3:00 pm
by Farmallgray
That looks much better. I would be happy with that angle if it were mine.

Re: 4a084 125

Posted: Thu Feb 23, 2012 4:40 pm
by shorty
Paul B wrote:I have a 4A032 in an Original and tried one of the reworked Mazda starters on it, but was not satisfied with it. The gear mesh was not too good which made it very noisy when engaged. I found a stock 24 volt starter and use it with a single 12V Wal-Mart lawn and garden battery (335 CCA). As long as the battery is fully charged, it will more than last thru numerous engine starts at a weekend show. I realize your engine is bigger displacement wise, but give the 24V starter a try with a fully charged 12V battery, might work. A small size 12V car battery may work better for you than a L&G size battery.
I'm a new guy here. What engine is in your original cub?
Thanks shorty

Re: 4a084 125

Posted: Thu Feb 23, 2012 5:23 pm
by Paul B
It's a 4 cylinder, 32ci, Military Standard engine, this one built by Teledyne. It's a military designed engine that was built by several different companies. All parts have to interchange regardless who built the engine. Government says it develops 6 hp, but they supposedly dyno 18 to 20 hp or so.