OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Two Stroke Lawn Mower Frames Victa 550 Pro - How to replace drive belt?

Hi N1KK0,
Do none of these have belts on them? What happens if you remove the tensioner arm, can you get a belt to fit and then drill a new hole in the tensioner arm so it can then put tension on the belt. Sometimes you just have to alter things to get them to work. I know this probably isn't wat you want to do but if the grass is getting too long you might just have to bit the bullet

Is it possible that the rust on the drive pulley, paired with some possible pulley damage on the motor one (looks like a groove in it) means the proper belt isn't fully seating?

This might take a few vital mm out of the equation

https://www.outdoorking-forum.com.au/forum/u...0-sp-not-working-help-plz.html#Post67755

This diagram lists different idler pulleys

Maybe someone threw on the wrong one somewhere along the line?

This is why I prefer a push mower with good bearings!!
I only saw a video last night of a guy in America resurrecting a Snapper SP mower and among the things he did was take to the pulley grooves with a small wire brush on an air tool to clean them up.

Or you could turn the tensioner pulley down or make a smaller one. Plenty of ways to skin a cat

Firstly, much thanks to all for their replies - I will try to respond to each as personally I hate it when I try to assist others and are ignored and I can only assure folks I genuinely appreciate the assistance. :-)

I've attached a few more pictures taken this morning which might support and assist with responding and having folks understand what the issues are:
1) Rear/drive pulley on spare 550 Pro
2) Engine shaft pulley on spare 550 pro
3) Engine shaft pulley on IN USE 550 Pro
4) Belt drive area SPARE 550 Pro - M36 rubber belt on, tensioner arm is FULLY engaged, note belt is SO TIGHT only a few mm of movement possible - can't be correct. Its way too tight to properly engage it and it'd either move constantly or burn/abrade the belt.

Hi NK,
Unsure what you mean - for the photo of the pulley I took the belt/s off to show the size/condition of them. I can assure you I've plenty of belts here - just not sure if any of them are useful. ;-)

Yes, I see what you're saying, but due to a couple of raised areas of the base, moving the tensioner arm, while still having it face backwards would be a very messy and tricky exercise. If you look at picture 4 - of the belt area where the tensioner arm attaches and also to the rear right of it are two raised sections - they'd be near impossible to work around and you need them as stops for the arm which is under tension. Good idea and I do stuff like that at times but I suspect it'd be very hard to do on the 550 Pro's belt area.

As always when the 550 Pro is not working - which has basically be constantly. I instead use the 21" Honda utility mower....not fun to push I can assure you. I will pop some pictures up soon as I am sure you guys think I'm a massive whinger but it's a tough property to mow for a bunch of reasons. :-)

The rust is pretty marginal - I don't think there's less metal of any great amount due to it. The ONLY one where I think this might be less than ideal is on the engine shaft pulley. If you compare the pictures I took of the spare and current use 550 - the IN USE one is missing about 1/2 of the bottom of it's pulley's lower lip. I am unsure how much issue this would make, it's definitely not the difference between a belt fitting or not but would promote more slippage.

I did try and fit the M36, M36K, M37 belts to the spare 500, which has better condition pulleys. The fit was seemingly the same - as shown the M36 belts were way too tight. Making this even more confusing I actually realised I had two old and badly damaged belts that came WITH the mowers. Too damaged to use, but they were on them and working when I bought them. Well one of them has feint markings that appear to say M36 - its a rubber/standard belt but unsure how it was ever used when close to new as it's far too tight.

As I said I am unsure that it's really much of a factor but unsure how one would even begin to go about swapping the engine shaft pulley off one of the 'backup' 550's I have? Obviously the engine needs to come off but after that I'm unsure - at this stage seems like a lot of effort for little assured benefit - but open to be told otherwise.

Hmm unsure about this - I have 3 idler pulleys amongst the bits here and all are the same size, can't imagine it's size changing would vary the speed much as all it really does is push the back of the belt in, making it apply more tension to the drive pulley.

To be honest I do as well - now I've welded up the terrible chassis on my Honda HUT216 it's exceptional - but my property isn't easy to knock all over with it - especially in mid summer needing mowing every 4-5 days.

Do you think the small amount of corrosion of the side walls of the drive pulley would be causing belt slippage? I suppose i could try and clean up, but I imagine it'd be hard to do as I can't get the pulley off nor great access to it.

If I had a metal lathe, perhaps. Alas working with what I have onhand it's tricky, again I'd like to think it shouldn't be this hard - a simple belt change should work but alas not.

Ok so looking at the tensioner pic, what happens if you disconnect the cable, the tensioner should only have the spring tension on it?

I would personally be doing what someone has obviously done on the red one - get an angle grinder and take a bit off the tensioner

Yes, thats right - but then with the correct belt in place (and the M36 thats shown in the picture IMHO can't be the correct belt as it's just incredibly tight) - but then how do you engage the drive or stop the drive - as you can't have both at the same time.

Well spotted - that said I am not sure exactly what that would help - as mentioned that image has an M36 belt installed and it was far too tight to be useful - you could not get the tensioner arm to even move a couple of mm at most and it certainly didn't add any 'tension' to the belt. With the two old and unknown belt sizes, when you engage the drive - the tensioner arm moves out quite a lot and adds a lot of tension to the belt.

So if one did cut off some of the arm that'd do nothing - not to mention that the idler pulley is just about the same width, so you'd just have the idler pulley rubbing or perhaps even worse not being able to turn as it was against the raised bit of the chassis.

Ok, my next step would be get 2 bunnings garden hooks and hang something heavy off the M36 belt to stretch it haha.

You have done all the right things so far, and I am at a loss - especially if the other one works with a m36

:-) Thats not the worst idea - I was trying to take a picture to show the difference in sizes of the belts when I stretched them out off something under tension. Amazing how much the 'assumed' M36's had stretched - and yet the brand new ones were impossible to use

Honestly, you'd be amazed how much you're saying that is appreciated as I do not consider myself knowledgeable in this area - I muddle through as best I can - and so you wonder am I doing something wrong or half arsing - as it's gone so badly. So that it's just a really tricky mess is actually oddly good to know. So much thanks. :-)

PS. Not sure how I'd be able to 'safely' stretch the M36's - as any weight hung from it would place a lot of the stress in just one spot i.e belt is hung over one or a couple of hooks. It'd be a fine line figuring out how much to hang to do anything but not to damage the belt.

If you remove the tensioner and the belt fits nice and loose then you have to adjust the tensioner so that it tightens the belt. Should not be that hard to work out, just use whatever belt you like and modify the tensioner to fit. I didn't get an answer but do the other 2 have belts on them or is this the reason the PO got rid of them because he couldn't get belts to fit

Yes, I understand how it 'should' be - but as I said I have literally tried M36, M36K, M37 and M38 belts - and none seem to work correctly. So please understand that unfortunately it is not as simple as it seems. I can only assure you 'd prefer to do just about anything else than spinning my and your wheels on this.

Again it's not just as simple as 'well just modify the tensioner' - I get what you're saying and in other situations perhaps one could but I'm not at that point yet.

I believe I did answer you, I was not clear what you meant by was there belts on them. There are currently no fuinctional belts on any of the 3 550's I have - they came with 2 very clapped out belts - one which appears to be a very worn and stretched M36 - the other I cannot read. They work well for a very short period with the best of these two on. But they end up having issues. As mentioned a number of times when I try the M36 it's just incredibly tight and cannot be the correct belt - you cannot move the tensioner even a few mm - so engaging and disengaging the drive is near impossible.

I can't comment on why the PO sold them - my understanding was his late father loved them, bought up about a half dozen of them from the local council surplus - but he had to make room in his shed after his dad died. Beyond that I'd be guessing. :-)

Hi Tyler,

I would personally be doing what someone has obviously done on the red one - get an angle grinder and take a bit off the tensioner

Attached Images
Victa tensioner.JPG
This looks very obvious but will only work if the cable is long enough for the tensioner to move back

As stated back to Tyler - I am pretty sure whoever did this - and we're assuming this was 'by design' didn't really know or achieve what was desired. As the tensioner arm rest against a raised area of the chassis, with the spring pulling it back to here. The idler pulley is of a size where it will almost hit the raised area IF you go removed part of the arm.

And this is aside to the actual reason it's assumed they did this - as it still won't be able to add any more tension to a new M36 belt - as stated I literally broke the steel cable on one by trying to add more tension - the belt is incredibly tight and based on everything I've seen about belts, far too much so.

So my gut feel is that was a 'bodge' effort that achieved nothing - the only variables that can change and affect things are either the pulley sizes, pulley locations (which won't change) or the belt size - the latter being the most easily changed one. Anwyay it won't be solved today.

Just out of interest could you try the new m36 belt on the other mower that the old belt that looks like an m36 came off of.

wouldn't be the first time for dodgy manufacturing had stuffed up a belt

I hope it's a simple as that I know it probably won't be

Just out of interest could you try the new m36 belt on the other mower that the old belt that looks like an m36 came off of.

wouldn't be the first time for dodgy manufacturing had stuffed up a belt

I hope it's a simple as that I know it probably won't be

Tyler, much thanks for the ideas.

Yes, I have already tried all the belts I have onhand M36, M36K, M37 and the Gates M38 on both mowers - which appear to have identical pulleys and layouts etc. There was no noticeable difference or info I could ascertain from doing this.

:-)

Just to clarify, the new m36 belt did or did not fit the other one with the old belt?

I would just go to a local bearing place and get a longer belt, just take one that doesn't fit and get one a bit longer