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Hahn tiller, need help figuring this one out

1249 Views 4 Replies 2 Participants Last post by  paul kellam
I have a 1973 Hahn Heavy Duty Rotary Tiller, model #BPDT-124, series 8675, serial no. 1129714, (power reverse model). I used it in early May to rototill my garden. Ran like a champ and no problems. Today I wanted to use it to cultivate between the rows in the garden. I started the engine and moved the clutch lever to the forward position the tines didn't rotate. So I pulled back on the clutch lever to put the tiller in reverse and the tines rotated backwards, (you have to hold the clutch lever back to reverse the tiller. When you let go of the clutch lever the lever moves to the neutral position). After doing a series of forwards and reverses, I pushed the tiller back into the shop. This tiller uses two different belts. One for forward, (tilling), and one for reverse. I thought maybe the forward drive belt might have stretched or something so I put a new belt on it. I started it up in the shop and the tines did move around very slowing at full throttle and if I put in the soil the tines probably wouldn't spin. I know this is an old tiller and probably not very many around any more but this is a beefy unit with a cast iron gear box that I'd like to keep running. I thought about this all afternoon on why it will go in reverse and not forward. Anyone have any ideas or suggestions? I'm at a loss on what could be causing this problem and what happened since I used it last to cause this problem.
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sounds to me like the tension pulley is either missing or frozen? Are the belts routed right? It's simply amazing that a piece of equipment that old is still in use, I have a hahn mower from the 60's that still gets used weekly.
Hi Paul,
Thanks for the reply. That's what my son said today when I told him it's a '73!! Belts are routed correctly, but you know what, I didn't check the tension pulley to see if it would spin freely. If I get time I'll check that out tomorrow and report back. I bought this unit back in the '80's. I rebuilt the engine about 8 years ago. This thing is built like a tank! The more I think about it, you may be right. I'm thinking if it would be gears it wouldn't go forward or reverse. And because the forward and reverse are on two different setups, a bad pulley could be the culprit. I'll report back after I check it out some more. Thanks again.
You hit the nail right on the head! The tension pulley is locked up. Here are a couple of pics. The bearing is pressed into the pulley and staked in three places on both sides of the pulley. I think I'm going to use my dremel tool and grind out the stakes and install a new bearing. I got the bearing number and did a quick search and found they are available. Thanks again for your help. :thThumbsU


Lets keep these old machines running, Good work thanks
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