Hustler 980 resto update

[Meinfield]

Just finishing up a weekend of working on the 980. I got the Kohler 16 tuned up and running, adjusted the t-20 and finished the wiring. Now I am just waiting on the wheels to arrive, and I will put the top tub on and hit the trail for a test ride. I am curious to see how the Kohler performs. I kept this engine because these old K series engines offer a lot of bang for the buck. They are popular with the garden tractor pulling guys, and an alcohol burning K-341 is capable of 60-horse power if built correctly! A friend who builds racing kart motors built this one for about $300 in parts, and he claims it will put out about 25hp, not bad for $300 bucks and a can of red paint. I also am running 38 tooth main drive sprockets, and I was told that the original had 40 teeth? Anyone out there tried other gear ratios with the big tires? I went with keyed axels, so a gear change will be easy and inexpensive. I paid $28.00 ea. for the 26 tooth wheel sprockets and $34.00 ea. for the two main drive sprockets from BDI.

I noticed that the T-20 I just rebuilt is leaking fluid from the bottom left band plunger. I installed new o-rings but I guess the case could be warped or something? Any one have any ideas on how to stop the leaks?

[jerseybigfoot]

Nice job on the rebuild. I rebuilt a shorter tub model a few years ago that had the 16. The engine ran well but do not run clean. Folks riding in back of me on trail rides complained. I since installed a 20 HP Command and am very satisfied. Less weight, smoother running, cleaner burning, more power.

The leak is from small scores in the bores that the plunger fits in. Unfortunately there is not too many cures. You can take the trans apart and try and lightly polish out the scores, you can install some double oring plungers that are available from Richard Clark or RI. You can also install a quad ring where the o-ring fits, they come in the same sizes the as o rings

[jpswift1]

What did your friend do to the engine to get the extra horsepower out of it? My friend is rebuilding a Hustler and he has the same motor. And your leaking plunger on the T-20 could be the result of putting in the plunger from the inside of the case. When you change the O rings/ seals put some ATF fluid in the holes so the O rings can slide and then re install the plungers from the outside of the case and you should be good.

[Meinfield]

Thanks for the info on the o-rings. Is a "quad ring" a larger type o-ring? I guess I will pull it back apart agian... I hate oil leaks! That command is a fine motor and should run forever.
As far as the Kohler goes, it is a stout engine with a heady duty cast-iron block and two quart oil pan. With a 3 1/4 inch stroke and 24 lb flywheel, the engine was already a torque monster. When we rebuilt it, we had reliability and "performance on a budget" in mind, after all, I do have a daughter in college. We added kohler piston and rings, installed new valves and a custom-ground "performance"cam (I have the cam specs from the company that ground it if you need them) with a much longer duration and a slightly higher lift, advanced the timing a little, shaved the head five thousands, re-jeted the carb and cleaned up the intake and exhaust runners. The governor was removed, and the motor should turn over 4k rpm. Really, the biggest power gain was in the cam.

[Meinfield]

980 Maiden Voyage

Well, today was the day. After two and a half months of restoring the 980, I finally got to test it out. My buddy and I filled up the tank and headed out to our property in E. Tennessee to run it a bit, get the t-20 adjusted and tighten any loose nuts that we might have missed during the resto.

It took a few adjustments to get the t-20 starting and stopping smoothly, and after reading a few of the posts on adjustments, I think I still have a little work to do. I had a hard time getting the machine to run straight at full speed, and it is not quite there yet. It seemed to pull to the right a little, almost like the t-20 bands were tight on the left side and slipping on the right but no amount of adjustments seemed to fix it entirely. Any one had similar problems? I read that uneven tire pressure might cause it to pull to one side?

The Kohler ran smoothly and had a lot of low-end grunt, but with the 26" mudlite tires the clutch on the trans would slip a little when going up steep hills or in mud. I did not replace the clutch spring during the resto, and a new stouter spring might be in order.

This machine is geared LOW eventhough I went with a slightly higher gear ratio than stock. Top speed was about 20 mph, and at a crawl it felt like it would tow a semi. Next time my buddy gets his Nissan stuck I'll be ready!

The mudlite tires and aluminum rims are lite, only about 35 lbs per wheel, and they pull like crazy. They really bite when skid steering, so slow turns on hard ground were a little rough.

Next up I will install the back seat, finish the winch wiring, fabricate an engine-cooling duct and exhaust, and start designing a roll cage...
Thanks for all the information guys, and I posted a few pictures in my gallery.

[mudbug3]

[QUOTE ] Meinfield

" The Kohler ran smoothly and had a lot of low-end grunt, but with the 26" mudlite tires the clutch on the trans would slip a little when going up steep hills or in mud. "

Order a red spring from Richard at Route 6x6 and your low end grunt will be even better. This should also eliminate the slipping probem.

Another guy ( overkill ) , who custom built an all aluminum 6x6 , had slipping problems as well. In fact , his slipped bad enough to smoke the belt when climbing hills . With the proper gearing change on the sprockets , different clutch springs on the driven clutch , plus , the large red spring on the clutch as well , he can now do 180,s on dry pavement .

[micmac]

Mienfeild,

Before you go crazy adjusting the transmission you might want to do the following. Adjust the T - 20 so both sides are equal and then play with the tire pressure to get the machine to go straight. I have a mix of old and new tires and couldn't adjust the T -20 to make it run straight. Also make sure the chains are of equal tension especially the ones of the T-20.


Mike

[Meinfield]

Thanks for the tips!

[jpswift1]

I love the pics of your rig in the gallery!!! That turned out to be quite a machine. I have to admit that I totally share the feeling of having the ability to pull anything with the low end torque of the BIG FOOT after getting behind the sticks. Its almost like you get goosebumps by driving only 3 miles per hour.

[mudbug3]

( quote )The mudlite tires and aluminum rims are lite, only about 35 lbs per wheel, and they pull like crazy. They really bite when skid steering, so slow turns on hard ground were a little rough.

Meinfield ,

You said the mudlite tires really pull good,,but how well do they swim in the water ?

[jerrynuss]

Do you have any pics of the chains from the transmission to the axle and how you adjust them? I have one I am working on a complete rebuild and would like to see what you did.

[jpswift1]

There is an idler sprocket that is adjustable on a U channel on most of the later models, and all of the 980 BIGFOOTs I believe.

[Meinfield]

I uploaded a picture of the trans in my gallery; if you need another I will shoot one that shows the main sprocket as well. Like Jp said, there is an idler sprocket that slides up and down a u-channel to tighten the chains. The idlers are can be purchased at BDI or Motion Industries, and you should consider installing a heavy-duty chain on the transmission output gears; these chains take a lot of abuse and a cheap chain will stretch and wear out your sprockets prematurely.

Hey mudbug, I have only had the supergrips in the water once and they did not swim too well, not like a rawhide. I turned the treads around and hope to get it back into the water soon, so I will let you know if it helped any.

[Meinfield]

Hey Guys, just wanted to check in and post a few more pictures of the 980.

I finished the rear seat and rear screen installation, as well as an exhaust.

I replaced the OEM Salisbury clutches with a Comet Duster 90C drive and driven unit. I hope I am not going out on a limb here, but this seems to be a great upgrade over the factory clutches and has several advantages:
The Driven unit is larger in diameter than the factory unit so you get lower "gearing" initially. It also has 6 different tension settings from 6 - 22 lbs so you can really dial in the rpm range to fit your motor and gears without buying extra springs. Thirdly, you get a .78 - 1 overdrive at top speed, nice! All this for less money than the oem clutches! The drive unit has many different combinations of weights and springs so it can be adjusted as well. I am running the pink spring (1800 rpm) with 1 and 7/8 pucks and this seems to work well. Drawbacks -the driven unit was a tight fit (only about 1/2 inch of clearance between the belt and the frame rail) and had to be bored from 3/4" to 7/8" to fit the t-20 out put shaft.

eBay Motors: Comet 90D Driven Clutch 3/4" Bore, 1-3/16" 212299A NEW (item 200133929448 end time Dec-23-07 05:27:01 PST)


I also switched my main drive gears from 38 to 32 teeth. This really brought the Kohler into its ideal rpm range, and with the new clutches I get tons of low-end pull and a 25 - 30 mph top speed.

I got to sing some praise for the Old Kohler K-341, this thing runs great! I almost tossed it when I started the rebuild and I am glad I didn't. Yes it is a single cylinder and yes it vibrates like hell, but it runs like a scalded dog and sounds awfully mean! I will shoot some video next time I have it out.

I had to fabricate a rear floor out of 3/8" Poly. I cut the plastic with a jig saw, torched the seams to soften it and bent it to fit the curve of the body and the t-20 support and bolted it in while it was still soft. When it hardened, it held the bends perfectly. It worked really well and was easier than I thought it would be. This stuff is inexpensive too, a whole 4 x 8 sheet of black "regrind" HDPE was $60.

Hey bon, I read some where on a post that you were having trouble removing the keyed sprockets...I feel your pain! I had to polish the axles with emory cloth just to get the sprockets to slide off and they had only been on the machine for a couple of months. The setscrews seem to pit the axle and this makes it hard to slide the sprocket off. I re-installed mine with lock nuts on the setscrews and anti seize on the axles...hope this helps.
Next project is the roll bar and next spring I plan to build a v-twin. Life is good.
Thanks to all who have posted info, and to Mike for keeping a great site alive!

[boncrshr]

Hey Mein,

Looking really first class there! We really need to come up with an easy way to get those axles off......I'm thinking of trying an air hammer next time, there should be enough room with the outer bearing flange removed...you think? Maybe we could find some kind of a puller that would work? I also went with the hex cap screws and jam nut...so far, so good..........