Starting on a Marquis 20"

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wristpin
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I’m a bit surprised that

I’m a bit surprised that there is no check valve in the breather system. Normal operation on a small engine is that crankcase air displaced by the down stroke of the piston is exhausted via the breather but on the upward stroke the valve shuts creating a negative pressure in the crankcase to help keep it oil tight . Lesser versions of the Sloper have a poppet valve in a housing just above the front oil filler. For reasons lost in history, in our workshop those valves were known as “fuffle “ valves!

Chris G
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Yes interesting, not come

Yes interesting, not come across it in that way on large air cooled engines but see what you're saying. The outlet tube from the base of the block also seems quite a high place but maybe because of the engine angle/slope..., that tube emanating from base of the cylinder block is 300mm high and 6mm ID hence the issue in seeing down it, but got the bendy scope out to look down it, good power on the LEDs but poor definition as could not get down the tube - either way there does not look like a check valve to me?

Chris G
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Pics

Pics

Chris G
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Tedious saga of the valve

Tedious saga of the valve cover continues.after a good hot run today it was weeping a bit of oil again. As much as the edges have been leveled the bolt hole sections are still proud by next to nothing but making the top and bottom edges slightly curve away from the face. I cannot take anymore off as bolt ends are now fag paper thin and part of the the problem - that and the bolt hole are so deformed from previous abuse and not much to press down on.

Knocked this up tonight, not CNC by any, but all spot on. Tomorrow will attach the fuel pipe stand off and fit

Chris G
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Pic did not post, this time I

Pic did not post, this time I hope..

Chris G
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I was thinking of ali

I was thinking of ali braising the fuel line stand off with some 440c fluxed rods which work great with oxy/acetylene but did not want to risk any distortion and it would just be aesthetic anyway as there is no stress there - so just stuck it on with a blob of JB weld :-) flat, flush and solid, getting quite good at making these gaskets..all back together and run up for 15mins and not a drip - happy bunny.

robint
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which grade of jb weld did

which grade of jb weld did you use?  Have you found it reliable - its epoxy resin with attitude

 

My stand off is bolted on by one of the cover bolts (nearest). Mine has a grommet to prevent chafing

Chris G
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It is epoxy resin essentially

It is epoxy resin essentially with a much better applicable formula for this sort of thing (heat,, cold,  vibration, oil, fuel etc) nothing like that araldite crap.

Using the standard "cold formula, steel reinforced" jobbie, read the spec sheet for it once, well beyond for this. I've used it to fill engine case covers and all sort for over 10 years and its great to sand and paint as well. Its horses for..and nothing would surpass a well done weld but there are times when its just not worth it. I had an internal gear shift boss break on a bike once and was recommenced "Q Bond" that stuff is amazing in a tight spot for an instant glue - the powder and the grade of super glue they use is the secret. That boss has held for over 7 years :-)

wristpin
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Don’t agree about Araldite

Don’t agree about Araldite providing that you use the original “ slow version” it’s always  served me well  since model aero plane  days in the 1950s!

Q Bond is great. My other standby for tricky structural jobs is Belzona. Amazing stuff.

wristpin
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Don’t agree about Araldite

Don’t agree about Araldite providing that you use .........

Sorry about the duplication, something had a wobbly and it won’t allow a delete.

 

robint
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thanx for the tip - agreed

thanx for the tip - agreed araldite was very limited and brittle

Now cyanoacrilate glues can be unhinged by soaking in warm water - innit.  Its how I got a gf off a toilet seat that had been pranked.  It gave a new meaning to pair bonding. had to unscrew the seat and get her to sit in a bath of hot water for a few hours.  I brought tea and jaffa cakes.  I'll never forget that sight of a shrivelled prune

Chris G
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What scale models were you

What scale models were you putting together with Araldite? !

Did you read on the Mig weld forum the guy who put an airfix model in a tray of turps to strip the paint off and by morning it had disappeared :-)

Read up on that Belzona - good tip - serious stuff!

robint
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Expensive  £25 125g

Expensive  £25 125g

robint
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Chris would I be right in you

Chris would I be right in you having an auto certes cylinder assy instead of the standard, cos I'm thinkinking (bad sign) that height adjustment on the std assy is a bit of a faff.  you'd need some ready made pieces of wood for a preset height - say 2" then some flat path and spanners and squating down, then you try it and its too high - what a faff cos our turf expert implies that you do a lot of adjustment for serious cylinder work.

 

So how does this stack up with the AC micro adjust system? Does this cylinder drop in to the std assy?  Is there much hassle?  Is it worth it

I thought I might fix a dial on the side to show implied height then fix some long bolts da dee dah

wristpin
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You do need to allow for the

You do need to allow for the squish factor of the grass , the curvature of the earth and the phase of the moon . Get those right and you're half way there....  but don't let the neighbours catch you at it.

Chris G
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Ants can play havoc with

Ants can play havoc with these precise measurements also, beware.

Its a Marques roller (6 blade) Certes is 10

The certes roller on this marquis is not original I don't think and although I have it working well now, would not recommend it as a quick mod, lots of messing around with the right spacers to get it to work smoothly.

 

robint
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ooh stop messin about

ooh stop messin about

For me, squatting, bending down trying to get the roller height right is bad news for my arthritis (so is meddling with mowers). So I wanted to get something better than suck it and see. If my Anzani hadn't run me over I would be on the case now, just have to wait for sprains to heal up. We are not on speaking terms just now.

hillsider
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If you are looking for a

If you are looking for a precision finish to your grass perhaps you need to invest in a Prism Gauge to allow you to view the true length of the sward. 

https://www.bernhard.co.uk/files/7713/3527/7058/Prism_Gauge_2012.pdf

Re your little upset with the Anzani I seem to remember a forum discussion about it's limited stability so now you are painfully aware of just what they are! Hopefully no lasting to damage to yourself - or the mower!

NM
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Bicycle stabilisers come to

Bicycle stabilisers come to mind

robint
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Outriggers?

Outriggers?

I was thrown to the ground in the blink of an eye, still having nightmares. Swore i heard a giggle but it was the scrape of chassis on scaffold board

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