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Collection, Preservation and Display of Old Lawn Mowers

Qualcast Petrol Classic 35S - Few Issues

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Hi All,

Firstly thanks to the admin of the site for setting up such a useful and informative website and forum.

The reason I've joined is that I've recently moved into my first house with a proper "garden" including relatively large lawn....hence need for a good quality mower.

Apologies for the long post in advance!!

To cut a long story short, I found my parent's old Qualcast Petrol Classic 35S sat in their garden shed (which is half dilapidated). It was looking quite sorry for itself, the rear roller was locked solid, rust everywhere.

I replaced the engine oil, changed the spark plug, cleaned out the petrol tank, replaced the fuel line which was blocked, cleaned it off, wire brushed all the rusty areas and temporarily coated them.

I managed to free off the rear roller, lubricated all the necessary bearings/bushes and the like, etc etc.

Amazingly it started after 3 pulls. However, it was hunting massively at idle and would only run with choke applied, plus fuel was leaking out of the air-filter.

I took off the carburetor and it was clear it had been put away (probably 10+ years ago) full of fuel. I found that the float had a big hole in it, the bowl nut was all gunked up too, plus the air filter had completely crumbled.

I've sourced a new float and bowl seal, cleaned the carb using an ultrasonic cleaner (which is amazing by the way!) and replaced the governor spring.

Something quite strange is that in order to get the float gap to the correct 11/32" setting, I need to bend the tab beyond flat, that is to say the little needle clip spring sits in it "back to front" as it were. If i don't do this, then the float (when carb held upside down) sits with a large upwards angle.

Once put back together, the engine started first time and idled beautifully, and runs fine without any choke applied. I ran it around the garden and the powered roller is all good, as is the cutting cylinder control.

So, I'm getting there slowly.

However, 2 major issues remain :

1. The carb still leaks fuel (at quite a drip rate) out of the air filter when either idling or even when the engine is turned off. This is a real pain...there is no fuel tap, so I have to drain the tank after use to avoid all the fuel exiting via the air filter and running down the back of the mower. When actually mowing with some throttle, there doesn't appear to be any leakage. Can anyone explain what could be causing this?

2. I've got a multi-sharp sharpening kit, and have already replaced the bottom blade with new. However, one of the cylinder adjustment bolts (the left hand side) is badly corroded and will not turn clockwise or anti-clockwise. I've tried lots of penetrant, and heat too, but it won't shift. Due to the location it's almost impossible to get mole grips on it. Does anyone have any tips on how to free it of (it'll likely need replacing when it does move as i'm worried abut it shearing off).

Finally, does anyone know where I can find the manual for the mower? (the mower is labelled TYP : F016305142 579. I think the serial is 082002262 and the date 2000)

And also, my carb is stamped 5148 which I've tracked down to be a Tecumseh, service number 640161 (I think this is a Series 1 Emission carb)....is there a manual for this available? Or does someone know the correct service kit for it?

Thanks and sorry for all the questions!!

Ben

 

 

 

 

 

 

 

Forums

wristpin Mon, 25/07/2016

Welcome.

Cylinder adjustment screw. I must qualify this suggestion  - has the machine got the cast alloy side frames or does your use of the word "Classic" imply that it uses the later design with pressed steel frames and the QX lift out cutter assembly? . If the latter  a similar situation applies but you only have to dismantle the lift out cassette..A couple of images of your machine will be of assistance.

If It's that badly seized I'd advise dismantling the machine to get at it. The reason being  that the screw passes through an abutment in the cast alloy side plate and into a nut, also captive in that alloy abutment. The important thing is to avoid fracturing that abutment which is possibly weakened by corrosion.  With the machine dismantled and the cylinder bearing carrier removed you will have enough free movement on the adjusting screw to get at it with a hack saw - a new screw and nut as opposed to a new side frame.

On the cassette machines there is even less room to get at the adjusting screw to remove the seized nut . A Dremel / multi tool will be useful or, with a new/sharp small diameter twist drill you can carefully drill a hole  in to a flat of the nut to weaken its grip on the screw. If the drill is almost the same diameter as the width of the flat the nut should release.

DIY sharpening kits.  Forget them , they won't sharpen a blunt cylinder and are only fit for keeping an edge on a properly sharpened one - if that.  If you have the cylinder out to do the adjuster it is the opportunity to have it done properly and the bottom blade skimmed to match. Don't rely on a new bottom blade as being properly flat, especially if it's a pattern part.

Not sure that I follow you description of the carb problem - a couple of images won't go astray - but is it possible that you have dislodged the float needle seat ( if it has a removable one)

Again, an image will help. Does the carb have the Tecumseh name  cast into it ?

If you've correctly identified the carb it does have a removable seat. If using compressed air in the carb cleaning process it is easy to displace the seat or blow it across the workshop.