Fitting a 5.5 hp engine into an old ride on mower

Joined
11 Jan 2004
Messages
170
Reaction score
4
Country
United Kingdom
Hello,
I have bought an old ride on mower (as per photo) with the idea of making it into a mini tractor /ride on for my young son. I have stripped of the cutting deck, heavy brusher/collector and all of the excess weight , redundant brackets , levers etc that altogether came to quite a bit of weight between them. The original engine was a 12hp Briggs and Stratton but unfortunately it had had it and so I have removed that as well. Basically with everything taken off it weighs quite a bit less. I have been looking for another mower engine to fit into it it and have been looking at Honda ones because they are fairly quiet. Originally I was hoping for around a 10hp engine for the torque but they seem to be very hard to come by and expensive. There are however a lot of 5.5 hp Honda engines out there for sale.
My question is if this engine only has to power the pulley system that drive the rear wheels of the mower and he is light should 5.5hp/ 6.5 hp be enough for this?
In case anyone is worried about him driving this he drives around on my existing ride on mower all the time and is used to how it all works and has complete awareness.
One other thing... if I want to make the motor even quieter would it be alright to completely clad the engine cover/cowel to muffle it further. I had thought of having " flue" or air intake to the air filter a bit like a snorkel on some four wheel drives coming through the cowel.
Thanks in advance for advice
James
mower.jpg
 
Sponsored Links
Going racing? A mate lives in the village which started lawn mower racing and drinks in the pub that started it.
How old is your "young son"?
A 6 year old is different to a 12 year old
Mopeds for 16 year olds are around 5bhp (4kw)
 
Look round for a Briggs and Stratton Vanguard V twin.....great engine and readily available.
Quiet, reliable and a good starter with a single carb unlike the Honda equivalent.
Happily the mounting holes are standardised but you do need to check the crankshaft pulley length so any belts are in line.
John :)
 
Sponsored Links
No worries, I wouldn’t recommend less than 10 bhp though, and preferably electric start.
You may have to faff with the exhaust, depending on the installation of the replacement engine.
John :)
 
Thanks John,
I have seen this one on ebay that apparently works well. I am assuming that this particular engine is supposed to be bolted on the way up it is shown here in first photo. Also I notice that the spindle has some sort of collar on it , do you think that could be hard to get off as I need to put a pulley on? Do you know if it has a key on the spindle for a pulley/
Cheers
 
Sure, that pulley is keyed on to the engine crankshaft which is parallel.....no tapers here!
It will need a good soaking in WD40 or whatever and maybe a puller to remove it, but there are a couple of crankshaft lengths and diameters to consider if you want to use the original pulley - which is a good move.
Obviously there is no exhaust silencer visible which could be an issue, and these engines usually have their own fuel pump operated by crankcase pulse pressure...its visible just above the left cylinder and they are reliable.
Great engines, these with a full flow oil filter which promotes long life. They are magneto start but have coils and a voltage regulator to charge the battery.
John :)
 
Going racing? A mate lives in the village which started lawn mower racing and drinks in the pub that started it.
How old is your "young son"?
A 6 year old is different to a 12 year old
Mopeds for 16 year olds are around 5bhp (4kw)
Times change - I was on a 40 hp Triumph @ 16 ;)
 
Well I've got a 1990 Kawasaki GT 750 with Watsonian sidecar waiting to be got up and running.
 
Going racing? A mate lives in the village which started lawn mower racing and drinks in the pub that started it.
How old is your "young son"?
A 6 year old is different to a 12 year old
Mopeds for 16 year olds are around 5bhp (4kw)
Some of the better road 50cc engines produce about 12bhp.
 
Sponsored Links
Back
Top