I looked for a tensioner, there is one that resembles it but applying
pressure to it didn't take up the slack in the belt. With the blades
engaged
I can easily turn them by hand, that's not right is it? Or have I missed
something eg. the real tensioner.

Does the motor mount have enlongated bolt holes that allow you to move the
motor further away?
Is the belt old, hardened and polished so it slides in the groove on the
pulleys? I don't know this mower, but many use A or B industrial belts that
are available from many industrial area bearing, nut and bolt and so on
stores. Or tractor/agri places often have a good range. You might find that
it is the same as a fanbelt for some cars and these can be had cheap from
your local cheap auto parts place. A buildup of oily deposits on the surface
of the V belt may also allow more slip than you want. I have cleaned belts
in the past with a petrol soaked rag, but I don't know this is reccomended
practice. At least it's cheap. (I'm broke too after spending all my money on
paying off the bank...)

eg. belt model number. I'll be chasing one at the local
bearing/engineering

Duh, I missed this before I wrote the above!
Must find more beer, mmm beer, mmmm beer!

shop that stocks lots of belts, they are always cheaper for crossover
parts
for anything. Need the info just in case they don't have a mower listing.

As you have the old belt then you can measure the length, or you can measure
the pulley diameters and the distance between centres or you can stick the
rideon in a trailer and take it down there. My unit I took with me on the
back of my little truck and they let me try the belt for size before
purchase in the carpark.

I find the Bolens poorly reacts to tighter turns. It tends to slide for a
bit (understeer) when you want to do a U-turn, even at slow speeds and in
low gears. Tyres are good but it seems like the problem is weight
distribution, too much on the rear. Am I right or am I using the wrong
technique or do "they all do that sir"? Have used mini tractor style
ride-ons and they go where they are pointed.

Does it have a diff on the driven axle, or is a locked diff with both rear
wheels turning the same speed. If so it may need to be riden like a cheap
trike where you have to lean out the "wrong way" to get it to press down on
the outside wheel and lift the inside wheel and allow it to slip. If both
wheels have the same grip it will try to drive straight ahead all the time.

Very surprised when I bought an air filter today. I was given 4 prices
from
4 shops, $18, $26, $32 and $40....guess which one I bought. The $18 one of
course! Made in the USA like all the other ones, someones making huge
profits.

My 8 horse briggs has a foam and oil air cleaner that I wash out and re-oil
when it gets dirty. It cost me an old car washing sponge...... A plastic
cage that sits inside it stops it from sucking in to much.

I bought this thing with eyes wide open, it looks pretty good for an
approximately 10 year old mower and has done lots of work judging by the
worn front wheel axles. It was cheap and I plan to persevere with it, it's
a
work in progress but with some help from you lot I may be able to work out
some short comings of owning such a beast.

Go for it, I use heap ofoldequipment. My tractor is an early 1960's heap
that is held together with bailing twine..... Evenmy keyboardis
twentyearsold!

Hope this helps,
Peter