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- Sep 17, 2017
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Hi,
Blackie's doing his thing putting lots of rain down again so I'm doodling.
Our Al-Ko 38BH 2.6KW BVS 143 petrol mower is now 32 years old and running perfectly. I service it each year at the end of the season and drain the fuel. Given its age and how miserable the weather is I've now got the mower on the bench just to tinker about a bit with it.
As usual with such tinkering it quickly escalates into a big job; I've worked on petrol engines for the last 55 years but never stripped a mower engine so a number of things are new to me; I'm used to points for precise spark timing but no points on this mower? Carb linkages have assorted springs etc. The spark on this mower is generated by a magneto; I'm used to Mag/Dynos from my biking days but all these had points so I'm on a learning curve and enjoying myself.
The top covers are now removed and yesterday afternoon I had fun removing the flywheel expecting to find points and condenser; my bearing puller didn't suit the size of the flywheel and not wanting to be brutal hitting it with an hammer I needed a way to gently remove the flywheel but it was proving more difficult than expected; I noticed three stopped holes around the flywheel boss; these holes measuring 5mm diameter and I was rather puzzled why these plain holes were there; I tapped the holes at 6mm then made a flywheel puller out of thick steel; had I resorted to using a hammer I'm sure a lot of damage would have occurred given how tight the flywheel was attached to the shaft; with the flywheel removed I was surprised not to find points but not to worry this is down to my ignorance regarding mower engines.
Whilst I'm tinkering and having got thus far why not remove the cylinder head and do a decoke and valve grind; I can also then check valve clearances and adjust if necessary. Everything will be thoroughly cleaned and the carburettor serviced too; this mower has given me a lot of service so time to give it a lot of TLC.
I've been browsing the web for spares but I'm just wasting my time; I can make a new head gasket and the original air filter can be washed clean so I'm not stuck for parts.
Kind regards, Colin.
Flywheel removed.
Over the years and given our rough terrain up the mountain the original wheels self destructed so I improvised; the two front wheels are castors and the rear wheels turned on the wood lathe from Meranti hardwood but just for fun I added the original tyres?
There's the easy way to remove such a flywheel being brutal using a hammer causing damage or there's a gentle way to remove the flywheel; I never ever abuse machinery so the gentle way it was. Here I'm tapping at 6mm diameter to accept a home made puller/extractor.
A piece of 3/8" thick black iron I had to hand being pressed into service; the flywheel was very tight indeed but was removed without it suffering damage.
So far so good; at a glance the key looks to be offset; the magneto can be seen on the right; a lot of debris has already been removed so it's now ready for a good clean. This mower was expensive new but worth every penny and it owes me nothing.
Blackie's doing his thing putting lots of rain down again so I'm doodling.
Our Al-Ko 38BH 2.6KW BVS 143 petrol mower is now 32 years old and running perfectly. I service it each year at the end of the season and drain the fuel. Given its age and how miserable the weather is I've now got the mower on the bench just to tinker about a bit with it.
As usual with such tinkering it quickly escalates into a big job; I've worked on petrol engines for the last 55 years but never stripped a mower engine so a number of things are new to me; I'm used to points for precise spark timing but no points on this mower? Carb linkages have assorted springs etc. The spark on this mower is generated by a magneto; I'm used to Mag/Dynos from my biking days but all these had points so I'm on a learning curve and enjoying myself.
The top covers are now removed and yesterday afternoon I had fun removing the flywheel expecting to find points and condenser; my bearing puller didn't suit the size of the flywheel and not wanting to be brutal hitting it with an hammer I needed a way to gently remove the flywheel but it was proving more difficult than expected; I noticed three stopped holes around the flywheel boss; these holes measuring 5mm diameter and I was rather puzzled why these plain holes were there; I tapped the holes at 6mm then made a flywheel puller out of thick steel; had I resorted to using a hammer I'm sure a lot of damage would have occurred given how tight the flywheel was attached to the shaft; with the flywheel removed I was surprised not to find points but not to worry this is down to my ignorance regarding mower engines.
Whilst I'm tinkering and having got thus far why not remove the cylinder head and do a decoke and valve grind; I can also then check valve clearances and adjust if necessary. Everything will be thoroughly cleaned and the carburettor serviced too; this mower has given me a lot of service so time to give it a lot of TLC.
I've been browsing the web for spares but I'm just wasting my time; I can make a new head gasket and the original air filter can be washed clean so I'm not stuck for parts.
Kind regards, Colin.
Flywheel removed.
Over the years and given our rough terrain up the mountain the original wheels self destructed so I improvised; the two front wheels are castors and the rear wheels turned on the wood lathe from Meranti hardwood but just for fun I added the original tyres?
There's the easy way to remove such a flywheel being brutal using a hammer causing damage or there's a gentle way to remove the flywheel; I never ever abuse machinery so the gentle way it was. Here I'm tapping at 6mm diameter to accept a home made puller/extractor.
A piece of 3/8" thick black iron I had to hand being pressed into service; the flywheel was very tight indeed but was removed without it suffering damage.
So far so good; at a glance the key looks to be offset; the magneto can be seen on the right; a lot of debris has already been removed so it's now ready for a good clean. This mower was expensive new but worth every penny and it owes me nothing.
