true true..
but it's not impossible.. just not very practical.
a chainsaw engine contrary to what you've been told (I think you just misunderstood to be frank)
has nearly no torque and is typically all rpms.. which is as mckutzy said good for cutting wood (more teeth per minute bite the bark)
not too good to propel a kart (where you need significant torque to push you up a hill )
That being said.. gearing.. excessive gear ratios can solve that, likely a two stage reduction will be needed to compensate.. but it is possible.
And yes, the same holds true for a bolted chassis.. it's unpractical, but possible.
Not buying a welder is not cheaper though, just more complicated tbh.
You can get a decent stick welder for what 60
https://www.amazon.co.uk/Dirty-Pro-...&qid=1518977914&sr=8-11&keywords=stick+welder
and a wire welder for 80
https://www.amazon.co.uk/Wolf-MIG13...TF8&qid=1518977972&sr=8-9&keywords=mig+welder
and while that involves learning a new skill (which can be fun or a PITA depending on your personal learning experience with it)
grade eight bolts are expensive('ish) so do yourself a favour and double check..
watch the colin furze build videos over and over again, cound the bolts in their respective sizes..
(take notes) carry said list to the hardware store and see what they will cost you.
You must not use used bolts, if one's stretched or weakended for one reason or another is impossible to tell with the naked eye and can be a risk for your health.. so just don't.
Anyways, I'd be amazed if that pricetag is less than 40 pounds for the bolts...
And with that I'm going to break that last thing..
building a kart from new materials for 200 pounds is way more difficult than finding a used complete funkart on ebay/craigslist/gumtree whathaveyou for a lower price than that
(even INCLUDING the engine)
Since a set of kart wheels (again you cannot use cheap 10 bucks a pop dolly wheels for a go kart) can easily set you back ~100 bucks at least half that used mostly.
And then you have no bearings, bushings, steering components etc..
that money's quickly gone if you make your own kart.
Don't get me wrong, MAKING a kart is great and we really like to see you doing it and help you wih everything we can on the way.
BUT it's not the cheapest option to go for mostly.
bolting is not necessarily cheaper than welding, and making is not necessarily cheaper than buying used.
So again, we will not stop you, we just warn you about the downsides.
Check all other options first, to see if there's a better one for you.
'sid