An engine to help me learn

[Uncle Denz]

Hello all

I'm after some suggestions of a cheap, simple engine with plenty of cheap parts about which I can work on to help teach me to strip, rebuild etc. Have done minor repairs etc before, fairly mechanically minded, tend to farm machinery and know how things work but would like an easy engine to start understanding from scratch. Not fussed about type of bike it's from but might want to put it in a frame at some point etc. Availability and cost of parts, manual and knowledgeable help for when i wil inevitably need it is more important!

Grateful for any ideas or pointers?

[cozi70]

The Honda cub engine,copied by the pit bike fraternity. Ranging from 50cc to 125cc+, 3 and 4 speed variants,manual and semi automatic.
It's a good insight into the basics of gears and selectors,crank and clutch,and cheap for parts due to the popularity and copying.

Colin J

[Richard Simpson Mark II]

If you just want an engine...go to the local tip and scrounge some old petrol mowers...it's how Guy Martin started.

Then buy one of those horrible little Chinese 125s that dissolve into rust after a couple of years and have a go at that.


HINT: Most engine work is actually easier if the engine is in the frame.

[Hugh]

Greetings,

I would totally support Colin and Richard's suggestion of small single cylinder Honda four stroke and/or two stroke engines taken from a scrap wrecked bike. Lawnmower engines are great for the same purposes.

Go along to your nearest motorcycle breakers and ask what they might have that has been laying around on their shelves and would let you have simply for dismantling purposes. I used to buy a selection of such engines each year for our students to work on and simply give them back for 'weighing' in at the end of the year. We were very lucky because our local motorcycle shops were very supportive of our efforts.

Ford Escort ohv engines are excellent for the same purposes and because they were so readily available they were cheap.

We would also cut them up to make specific teaching aids, purposefully snap bolts in the cases to drill out and re-tap, pass parts on to our engineering colleagues and they would use them for machining purposes too.

Our students used to make videos of their various tasks which they could use for their NVQ qualifications and we even used some for our teaching purposes.

Great fun

TTFN

Hugh.

[DaveCon]

This is very timely because my Christmas project is to get working on exactly this task.

I don't particularly like the idea of a very small engine like a Cub (or even an old Bantam) because to get the engine small, designers have to be a bit crafty with their mechanisms and assembly procedures. For example, one old British design you had to split the crankcases just to check the points and the Cub has that crafty auto-clutch to contend with.

I'm hoping to get a 125 4-stroke single or maybe a twin . If I ca get a bike I'll chop the centre frame section out to keep the engine mounted but get rid of the irrelevant chassis parts. Alternatively get the students to design an engine stand - old Haynes manuals sometimes gave instructions for this based on factory designs.

Like you say, great fun

[Mad Hatter]

Hello all

I'm after some suggestions of a cheap, simple engine with plenty of cheap parts about which I can work on to help teach me to strip, rebuild etc. Have done minor repairs etc before, fairly mechanically minded, tend to farm machinery and know how things work but would like an easy engine to start understanding from scratch. Not fussed about type of bike it's from but might want to put it in a frame at some point etc. Availability and cost of parts, manual and knowledgeable help for when i wil inevitably need it is more important!

Grateful for any ideas or pointers?

Where are you mate? I've got a Chinese 125 engine you can have for free, the parts are dirt cheap as well and the hanes manual is not that bad.

[Uncle Denz]

Hello all

I'm after some suggestions of a cheap, simple engine with plenty of cheap parts about which I can work on to help teach me to strip, rebuild etc. Have done minor repairs etc before, fairly mechanically minded, tend to farm machinery and know how things work but would like an easy engine to start understanding from scratch. Not fussed about type of bike it's from but might want to put it in a frame at some point etc. Availability and cost of parts, manual and knowledgeable help for when i wil inevitably need it is more important!

Grateful for any ideas or pointers?

Where are you mate? I've got a Chinese 125 engine you can have for free, the parts are dirt cheap as well and the hanes manual is not that bad.

Thanks for the offer. I'm in mid Wales, not far from Welshpool. Is it a copy of a particular engine?

[Mad Hatter]

Hello all

I'm after some suggestions of a cheap, simple engine with plenty of cheap parts about which I can work on to help teach me to strip, rebuild etc. Have done minor repairs etc before, fairly mechanically minded, tend to farm machinery and know how things work but would like an easy engine to start understanding from scratch. Not fussed about type of bike it's from but might want to put it in a frame at some point etc. Availability and cost of parts, manual and knowledgeable help for when i wil inevitably need it is more important!

Grateful for any ideas or pointers?

Where are you mate? I've got a Chinese 125 engine you can have for free, the parts are dirt cheap as well and the hanes manual is not that bad.

Thanks for the offer. I'm in mid Wales, not far from Welshpool. Is it a copy of a particular engine?

They're a clone of the old honda CG pushrod engine, pretty basic and low powered but nice enough to work on. I've actually got 2 and a complete bike that I put together for my Mrs to ride with various bits taken off and s cut down seat because she's not that tall but we've replaced it and just stolen bits from it

[Uncle Denz]

I've just been reading about this engine and have seen that it features in many of the Chinese 125s, sinnis etc so seems ideal to start me off. Are there any haynes manuals for the chinese versions or would you go with one for a honda engined bike?

[Hugh]

Greetings again,

So far as I know there are no public retail readily available workshop manuals for the "copy" bikes, not sure that they even produce trade workshop manuals expecting their basic bikes to be 'understood' by experienced trained motorcycle technicians for other marques.

It might be worth your checking out the Haynes website as their basic TechBook manuals are quite good quality;

https://haynes.com/en-gb/motorcycle-man ... -techbooks

Once you have sourced your donor engine, different engines for the same model could mean a different book, then you can narrow down a specific workshop manual, probably from the Haynes or Clymer range of books;

https://www.clymer.co.uk

If you can not find an answer in the book then you can ask questions on here or at your local motorcycle club. Depending upon where you live you could contact your local TRF Group as there will undoubtedly be some body available who could guide you;

http://www.trf.org.uk/find-your-regional-group/

TTFN

Hugh.