Bosch Power Tools Rotak 37 LI Questions & Answers

remove all the screws and use common sense.

Thanks, last screw found (in plain sight) underneath, I found my common sense, motor out and ready for my next task. Thanks again

Same thing happened to me about 6 weeks ago.... I ended up plastic welding it back together in situ using a soldering iron and some ABS 3d printer filament to "beef it up". It's holding up so far.

Thanks for the response. That sounds like a good fix. I don't have access to soldering equipment so I'll have a chat with a place that fixes stuff.

I have repaired the leaver by drilling new hole and used a bolt. I have tried various methods but found none very successful. The price for the replacement parts is outrageous. In the end I drilled, bolted and plated the broken bits with aluminum so the mower is now a fixed height. Bosch should pay their long suffering customers to take their crap off their hands.

That also sounds an interesting fix. I'm hoping to take another look to see what I can do. Thank you

sounds like you have a dry joint; probably from all the dust and dirt over 12 years - if you are able to pull the mower apart to fault find it should not be too difficult to work your way through the circuit to locate the problem.

Thank you so much Graham. I disconnected and checked every connection, but found no obvious corrosion or contamination. I then reconnected everything with a spray of Inox, that could only help any dodgy connection. Then, the test .......... It ran perfectly for 15 minutes while mowing our overgrown bit of lawn. Thanks again for your advice. Regards, Peter R.

Hi. I had the same problem so sprayed the battery with silicone spray. Still didn’t work so I purchased a ryobi. Then my partner gave the key and battery a good bang in and voila it now works. So I have 2 mowers now.

Hi Belinda, I had the same problem. I've had my rotak for about 10 years now (I know right), but a couple of weeks ago it started behaving like this. Even though the battery was fully charged, it kept starting and then stopping a couple of minutes later... Very frustrating. After trying a few things, I realised that battery was slowly coming off its fixed position due to the vibrations and eventually causing it to stop. When I would start the motor and then manually hold the battery down in its position by hand it would continue to work. Not sure if that the issue with yours as well. I then came up with crass solution and used an old bicycle tube to hold the battery down firmly. And now it works with no problems. Hope this helps. Cheers, Manish

Hi Manish! Thanks so much! Not sure if I’ll be able to fix it as well as you did but it’s helpful advice! Best wishes Belinda

You probably need a new spring (stainless steel, not plastic). Springs get worn out, especially if you like me have an uneven lawn. No 43/10 in the diagram here external link . Spare part number for me was F 016 L66 108 (but I'm in another continent). Just remove the case (4 screws, torx bit or something like it, not ordinary 6-sided) and turn it carefully upside down (it's connected to the motor via wires, so no dragging!). You'll see the spring in the red plastic part.

Thank you so much for taking the trouble to answer! That’s really helpful advice.

I have same problem. Bought August 2019, when my husband sadly became I’ll, and the hefty petrol one was awkward to manoeuvre round trees etc…. It’s really light and manoeuvrable for me, but then it started cutting out, problem since last year, but worse this year, every few minutes. I discovered pushing battery back in worked but Very frustrating…and takes ages to cut the grass…I’ll try wedging it in. Also, would cutting take longer if the blade is blunted?? It has some indents on surface where I’ve hit gravel or the like!! I have spare blade but can’t get the bolt undone,(I’ve held the blade still with screwdriver as instructed, but just can’t shift the bolt. (Manly strength has its advantages!!)

Thanks ManishU, I've used your wedging solution to get my Rotak 37 LI running properly again. I just used a bladed screwdriver to wedge the battery and it works beautifully. Best Wishes, Peter

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Try looking for dirt in the bottom of the batteri room. If the batteri thereafter is a bit loose, put a small woden wedge under it, from outside, so it is proper fastened during work.

Please let me know if you find a fix as mine has started to do the same thing today

did you find an answer? mine has the same problem

Not yet. I will first replace the motor power relay made by Tyco. I found it on the web and a new only costs $10.

Did you get to the bottom of this? Have the same issue. Took handle apart and just pushed on the central switch, same issue. Took off central cover and gave it a good clean inside, same issue. Checked key and battery indicator full.

Literally just figured it out! After tearing apart the mower, it was just the battery needing to be wedged in, I used 3 tile/grout separators and wedged them under the battery unit. Initially got my wife to start the mower while I physically held it in place (by lifting and pushing back).

Hope this helps someone somewhere!

Put a screwdriver in the hole in the baseplate and turn the plate until the screwdriver falls into a slot. Then take the nut off

The green light will stop blinking.

Have a look at the battery contacts. I found some leaves trapped between them. Hooked them out with a screw driver and bob's your uncle!

Don't think so you can prove it by shorting out terminals with piece of wire.

What safety key? The button you have to press before you pull the trigger bar? How would that wear out? If the mower is running then all is good. I'd only worry if it didn't work. Your not likely to have electrocution problems either from a DC battery. But if you are worried get it checked at a mower shop

Check for jams, if the rotor even spins anymore. Maybe the motor is burnt, or there's a contact problem in the circuitry, wire has been cut. But there isn't an ignition so to speak, as it is purely electric based.

There isn't exactly a lot that can go wrong. A speed controller, the motor itself and a few switches. Have you checked the key, the handle switch and the battery terminal on the mower? Just look for anything that looks damaged or doesn't click anymore. After that, all you can do is have someone look at repairing it.

Thanks for the suggestions teedeebare I will check all those things tomorrow. Here's hoping I can find something.

Today I did check over the mower and removed the key then replaced it until it clicked back firmly into place and eureka the mower started. For those who may be interested the old battery worked fine after charging on the new charger therefore it was the original charger that had 'died'. Oh well I now have two batteries in working order. Very happy, thanks again teedeebare you saved me further expense.