Hi ,
I posted a couple of weeks ago about a suffolk super punch 17" ball bearing mower that I picked up at an auction and was hoping to firstly get running and then maybe restore. I was having issues with getting a spark and after cleaning the points and resetting it looked like I had fixed the problem as with the spark plug laying on the top of the block , i could see good spark. I decided I would clean the carb before starting properly and needed to wait for some bits to arrive and also decided to investigate why the drive lever wouldnt do anything ( fixed that )  so its taken till the end of last week to actually try and restart it .
So when the time finally came around , it started pretty much first pull and ran for about 20 secs .... Then stopped , wouldnt start , no spark . I metered out the spark plug cap and no resistance ( open circuit) .... I had changed the original cap for a new one as that was open circuit too . The new cap can be dismantled and has a small resistor?? inside which i presume is for noise suppression? and that measures no resistance so I am assuming had blown. I figured maybe the new cap was of poor quality so ordered another from a different supplier and fitted that today ( metered it before I put it on and it was fine )  , again , good spark on the block , started first pull and ran smooth as you like for 30-60secs then stopped , wont start , no spark , resistor open circuit again.
So , im at a bit of a loss as to what is causing the resistor to blow in the cap and what can I do to fix the issue ? Starting to wonder if I am flogging a dead horse but it wants to run and is a functioning motor and mower .... For 30-60secs 
Wondering if I should just move it on to someone who has better knowledge of these old mowers ( I basically have none ) ..... but I'd really quite like to win this battle

Thanks in advance for any advice or info

Cheers

Paul

Ps . Cant find my original post anywhere , and my profile shows no posts ??

Hi Paul. Your profile says 6 posts when I look at it. Strange, I'll look into this.

Regarding the mower, as a test try adding a small spring out of a ballpoint pen or piece of wire instead of the resistor and see if it keeps running.

Hi , when i look at my profile now , all the posts r there but definitely weren't this morning . Will try the spring and report back

Hi Mick ,  I tried a pen spring as you suggested and got a good spark again , mower fired first time and ticks over great..... so great that I mowed ( well more hacked and rolled ) the lawn with it    . Am I ok now to leave the spring in there ?
Next job after that is to get it cutting better .

Thanks very much for your help 

Quote from: Paul434 on August 14, 2023, 07:11:31 PMAm I ok now to leave the spring in there ?
Next job after that is to get it cutting better .

Sure, I would just leave it if it's working. Strange that those suppressors were failing though, I've never had that happen apart from them falling to pieces. 

So you just going to set the cylinder to help the cut, or are you going to strip the cylinder and bottom blade out and get them ground? The latter isn't cheap these days. 
 

Well , there seems to be a pretty big gap between the bottom blade and the cylinder so was gonna try and adjust that first.
I have also seen these multisharp things to sand them down and then videos of grinding with paste but I have no experience of that or how effective they are.
I would quite like to strip it all down and re paint etc in time but would like to make sure it will work properly before i put that kind of time in.

That will be why it's chewing the grass, there should be no gap. Works just like a pair of scissors when set correctly (assuming it's sharp enough as well).

Remember to check and adjust drive chain as this will alter with cylinder adjustment especially if it's a long way of the bottom blade. 

Ok , will do , thanks 

Hi ,
Quick update . I adjusted the cylinder closer to the bottom plate and had another go , it did cut a lot better but I think it would benefit from a sharpen . Was gonna have a go at back lapping and see what that does . I think my grass was too long to start with as the motor seemed to bog down a bit as i went along a row. I ran over it with a modern mower first to reduce the length and then had another go and it managed much better . Its obvious that this machine is for using much more often than a modern mower will let you get away with and it really just for clipping the grass rather than hacking at hay !😂🤣 and thats fine , just testing its limitations 😅.
If I do get around to a full strip down and re paint etc , I will probably get the blades re ground but thats a job for the winter ( just not necessarily this winter 😄)
Have attached a pic of the second lawn attempt... pretty pleased with that for a £2 auction purchase 

Hi Paul, as you said they are designed to be used regularly and on fairly short grass, if left too long it will fold most of it over rather than cut it. 

As for setting the blades, if sharp you should be able to cut paper with it as you set it up without it being wound down too tight against the bottom blade.

Garden looks very nice.  

Hi ,
I ordered some lapping compound and it showed up yesterday so I spent an hour late yesterday afternoon back lapping the blades and was pretty pleased with the results , nice shiny edges to both the cylinder blades and the bottom blade and easily cuts a piece of paper along the whole length. Had to knock a couple of bends out of the end of a couple of the cylinder blades where they had obviously hit a stone or slab or something in their past but other than that it was a pretty smooth process. Took it out and had another go at the lawn and it cut like a hot knife through butter , lovely finely clipped grass ..... been mowing every piece of grass in sight today , playing with my new favorite toy 😂. Think I'm turning into lawn guy