[Finalist] [24] RROD’s Sears Custom 6

Sears did great down at coalmont today


Behind me in this spot I accidentally showed up some jeeps that were recording a youtube vid and blasted through all the rocks they were fighting with


Most of what you can see from this view is part of the offroad park. Place is huge!


One small problem i guess, after being slammed on its side several times (the tractor is hard to roll backwards, it goes backwards and then falls to the left), it seems i busted the roll pin that stops the front wheel from sliding in on the spindle. Can’t really complain if that’s the only problem from hard riding for 6 hours straight!


More evidence of abuse lol. The steering wheel is a bit bent up too.

Welded the washers on the spindles. Moved them in a bit actually, since i took the bearings out of Mutt’s old front hubs and put them in these wheels, and the flanges on those bearings are a bit thicker than the old bushings. So now the front wheels are nice and tight on the spindles.

Ok reupload this one actually has audio

Dropped the trans to put the new 5.5” pulley on (4.5 previously). Went to a 1/2x80 belt. Moved upper belt guard with the slots in it, and did the same in the bottom after i pulled it out and put slots in it.


You can see here that reverse is between 2-3 and 1st is far removed from the rest of the gear ratios. A 2300 is better described as a 3 speed with creeper than a true 4 speed.


Anyway, the gears feel much more appropriate now. Reverse is now useable, 2nd is a nice trail cruising gear, 3rd is a nice takeoff gear and 4th is great on the roads. 1st gear is still just crazy slow lol. Top speed is now 21.7, down from the previous 24.2.

I'm curious of your pulley size research.  I run a 7 engine 5 trans on the 2300 on dirty rat.  I forget it's top speed, but sometimes I want more. I run into belt slip if I go smaller on the trans when wet, and going larger on the engine messes up the clutch.  I need to rework that one day if I do want to go faster.  Works well now, so I leave well enough alone.

Top speed with 6.5 to 4.5 was 24.2mph @6200rpm on 24” tires. Down to 21.7 now. I think i was expecting about a 18% decrease in speed, this wasn’t quite that. More like an 11% decrease. This is probably due to the fact that I’m calculating by pulley ODs and not the actual “Pitch diameter” that drives the belt.

Nice thing about pulley swaps, once you have a top speed with one ratio you can calculate the % difference between the old and new ratio and then multiply your known top speed by that % to get a new theoretical top speed. Since this pulley is a deep groove it didn’t actually go that much different on diameter than the old one so i didnt see the difference that i calculated by the OD.

I did find my top speed was 18 @ about 4800 I think. The old oppy with stock carb and valve springs starts falling on it's face at that point.

I’m surprised your top speed is that low. I suppose the math does work out at that RPM.

This one definitely doesn’t breathe enough to make power over 5k, 6200 is just me holding it flat out on the road just to see what i can get lol. The low to mid range on this engine is definitely a perfect match for this tractor. Powerful yet very controllable. I don’t have a chance to use the top end much, most of my technical riding is slipping the clutch at mid throttle to keep smooth power delivery to the tires, instead of chugging at idle. The times i get into the higher rpms, it is mostly to use the momentum of the engine spinning down from high rpm to give a jolt of power when i let off the clutch- not being in the throttle until i need extra power makes things more predictable when lifting the front end. If that makes sense. It’s easier to demonstrate than explain.

I'm really contemplating giving those same tires a go on the front of The Green Machine when I complete my minor refresh.  I think they will work well.  The wide tires I have now seem to be a bit of a drag when it comes to soft ground or mud.

They’re a nice option for a taller pizza cutter than the stock 4.80s. They did just ok before i cut them, now they’re pretty great. Fit my narrow rims good too. For the price and actual intended application i cant complain.

RichieRichOverdrive wrote:

They’re a nice option for a taller pizza cutter than the stock 4.80s. They did just ok before i cut them, now they’re pretty great. Fit my narrow rims good too. For the price and actual intended application i cant complain.

Only thing holding me back is, I think the width would look funny on the tractor.

MightyRaze wrote:

RichieRichOverdrive wrote:

They’re a nice option for a taller pizza cutter than the stock 4.80s. They did just ok before i cut them, now they’re pretty great. Fit my narrow rims good too. For the price and actual intended application i cant complain.

Only thing holding me back is, I think the width would look funny on the tractor.

I’ll get a width measurement on these for you sometime soon.

Sears did great this weekend riding with @CraftsmanQuad19 at my place

The width on the 5.70-8s is right about 5-1/4” and height is just shy of 17.5”, though that depends on air pressure.

Wired in a tether kill as to be compliant with TTC rules. Used original keyswitch hole.


Scabbed the bigger carb off my GX390. It’s a direct swap to the 301 and is quite a bit bigger.


Bought this honda “stay choke control” off the jungle site. Allows you to add a remote choke cable like your typical briggs would have.


This is the plastic spacer between the head and carb. While port matching it between the head and carb (it was way off even with the small carb) i got into a little vent galley it had in the face, so i just decided to face the whole thing off snd get rid of it. It has the same galley in the face of the carb anyway. This also saved some stack height with the addition of the choke control so the air box doesn’t get into the grille.


Choke control in place. Cable attaches to left side there. You do have to trim the air box out for the cable to pass through.


Added some self tappers on the edge of the seat because the edge keeps coming off and letting the vinyl get loose.



The engine is happier on the top end with this carb but not happy on the low end. I was expecting a little bit of that, but not this much. I will have to play with the jetting this weekend and see if i can get any more out of it. Can especially tell the AFR is different by the lack of snap crackle pop on decel

So here’s a handful of 3/4” EMT all notched and beveled in odd ways…


What the heck??


Tree kickers!


The conduit is pretty light stuff but there’s lots of triangulation there, be interesting to see how these hold up. These will bolt on, just havent added the hardware to do that yet.

Finished up the tree kickers. Seem to work pretty good


Bent this piece up


Front axle brace i guess. The idea is to have the middle section in tension so the ends of the axle cant push back.


Braced the spindle arms.

I like your axle mod. I was always afraid of them being weak.

MightyRaze wrote:

I like your axle mod. I was always afraid of them being weak.

I’m sure time will tell if it helps any. Though i really am more worried about just breaking a spindle or ripping the end clean off the axle lol. It does seem to be welded well enough there at least.

Added a stiffer clutch spring. The old one was just barely enough to work when dry. You could feather the clutch with like one toe lol. Now it’s pretty firm.

Didnt get any pictures, but the sears did a little running around on trails at GER and was performing great until i broke the end of the steering shaft off. The fan gear is pressed onto a hex that is cut onto the end of the shaft, and it broke the shaft where it was turned down for the hex. Gonna have to see if i can press the old shaft out of the gear and cut a new shaft out of pre heat treated 4140, same stuff i made mutt’s straight axle out of. I like the sears steering so i’d like to keep it like it is.

Here you can see a distinct lack of steering gear. I’m thinking i might have to pull the engine to get this fixed.

Sorry to hear about your steering problems, but thx for the tip on the choke remote control.  Just what I need for my GX270 build.

@RichieRichOverdrive it took a minute for the picture to load I was thinking that the teeth were just stripped out but there is literally no gear there

torgo wrote:

Sorry to hear about your steering problems, but thx for the tip on the choke remote control.  Just what I need for my GX270 build.

Definitely an awesome addition. Beats reaching up from the seat.
Honda 16590-ZE2-812 Stay Choke... https://www.amazon.com/dp/B00AJTIZ4A?ref=ppx_pop_mob_ap_share

ranch king pro 08 wrote:

@RichieRichOverdrive it took a minute for the picture to load I was thinking that the teeth were just stripped out but there is literally no gear there

It was an instant no warning pop lol, i bet that shaft has been pretty stressed for a while and just finally let go. Sears seems to have problems with making parts too hard so they crack and fail instead of flexing, having some forgiveness before they break. I’m reverse engineering a 4 pinion 633a differential and every part of it is way too hard. No wonder I’ve seen those axles and side plates shatter.

@RichieRichOverdrive the 633a you're working on is it one of the Roper/ayp's or is it a newer one

Older one. I’m designing plate lockers for both 4 and 6 pinions as well, and a locker to use splined 6 pinion GT axles in the older 4 pinion.

@RichieRichOverdrive I'm interested LOL keep us updated. I wonder if the newer 633a would be as brittle