Sid James

[Sid]

Can anybody out there help locating a new Conrod for my170cc single cylender puch engine have one contact in Milwaukee but he seams to be struggling have found a tiger 90 engine wil this fit ? How big a problem

[John Wakefield]

I would think a Triumph T90 engine a bit big to fit a Pathfinder frame without major 'surgery' a Yamaha DT or TY175 engine would go straight in with new engine plates, & this mod has already been done, there was a such modified Pathfinder for sale last year on eBay. You should be able to pick one of these up from a bike breaker. Parts are readily available too.

[Brian Catt]

Which era do you want to work in? There is a very nice Honda 250 engined Pathfinder here in S. England, but a 230 would fit easier, Otherwise a Yam 175 DT engine or similar. My guess is that a C15 might just get in.

[John Wakefield]

Which era do you want to work in? There is a very nice Honda 250 engined Pathfinder here in S. England, but a 230 would fit easier, Otherwise a Yam 175 DT engine or similar. My guess is that a C15 might just get in.

Or a Honda CB125 four stroke (You can buy as new engines on eBay for around £300 http://www.ebay.co.uk/itm/HONDA-CA12...item2c6f2b14c9 this ones a twin with electric start) but loads of these in bike breakers yards. & with the Honda engines you would not need an oil tank like a T90 of C15.

[greeves246]

pathfinder engine swap

I have seen a t100 in a pathfinder he won the trial but front forks were strained
having ridden a pathfinder owning one and restored 2 ty175,s (both come under twin shock rule !) i recon a ty175 was a lovely engine (agree with John) with good power delivery.

Another period engine would be a MONTESSA OR A BULTACO ! SHERPA T or or
a starmaker trials engine.

[John Wakefield]

Starmaker would probably be as difficult to get spares for as a Puch, they were not that good for trials although the Fluff Brown ones are better.
Here is another Honda CG125 on eBay for £140 incuding cdi unit & coil. http://www.ebay.co.uk/itm/Honda-Cg-1...item3f29f77c12 These Jap engines are bullet proof unlike the old Brit & Spanish strokers. They make an excellent trails motor for a bike the size of the Pathfinder, Honda & Yamaha produced their own trials bike fitted with these engines, again the Yam 175 stroker would be lighter & easier to fit & as Garry says gives a good performance.
There is a DT 175 engine on eBay now http://www.ebay.co.uk/itm/YAMAHA-DT1...item58a52c0269 but £240 these do not appear to be as cheap and plentiful as a Honda 125.

[greeves246]

Rtx engine

Rtx engine ebay trials twinshock

http://www.ebay.co.uk/itm/rtx-trials-regent-minsk-cossack-engine-new-old-stock-project-spares-or-repaire-/141069071729?pt=UK_Motorcycle_Parts_13&hash=item20d85f3571

as many trials engines as you like !


gary

[Colin Sparrow]

I've often thought a Tiger Cub engine would give a Pathfinder the low-down snap it needs. They must weigh about the same as the Puch. And at least they're British.

Does Sammy Miller still do trials-prepared Cub engines?

[Phil Hyde]

Triumph T90 in a Pathfinder

I see no reason why a C range Triunph engine should not fit the Pathfinder frame. In essence the bottom frame rails will need cutting out and the engine installing as a stressed member. I do not know of any examples but remain keen to improve the Triumph-Greeves information database. Limited help is available if only as a paper design.

As with all conversions it all depends on the use.

[John Wakefield]

[QUOTE=Colin Sparrow;15587] And at least they're British.QUOTE]

Puch is not British Colin

[Brian Catt]

John.....I assumed the British comment was about the frame and the Triumph engine....
Colin, has Sam ever done Cub engines? He does....sorry, used to sell Cub components, but I didn't know he prepared Cub engines for sale. Some specialists exist, but they know how to charge! Cub sounds easier to work on than Puch, but it depends what spec you want in the Cub engine. A 230+ cc engine can be built for Trials, but you will need deep pockets.

[John Wakefield]

Good points there Brian, I think the thing here is that with relatively few Pathfinders (or at least rideable ones) left its a shame to cut and shut frames to suit bigger engines, I think Phil would agree with that. Like all old bikes it was done in the past but now with things becoming collectable & prices rising you dont want to be 'ruining an investment' If it can be re engined without cutting or altering the frame then I think thats the way to go. A friend of mine locally (not a GRA member) is doing up a Pathfinder project he bought from Dick Dunkley with a 125 Puch engine, it fits straight in & parts are a bit more available, it will not be any good for trials but to ride on the road as this guy intends will be fine, at least it gets another Pathfinder up & running.
There is a web site for the Puch M125 http://www.puch-m125.org.uk/technical.html

[Colin Sparrow]

Of course I meant the Cub engine, John.

Brian I'm remembering from years back when SHM was making very nice Trials Cub replicas.

Shouldn't be that difficult to acquire a Cub engine to do up anyway. I mean, I know where there's a Cub in bits...

My thinking was that it is a combination which could have been done "in period", and probably wouldn't require the Pathfinder frame to be hacked about.

On the subject of altering classic vehicles, a good principal to abide by, surely is "No irreversible changes"

[Gr11mpy]

Guys, just a few things to remember, as I'm sure you all know (I also always choose to forget these when getting excited about the start of any project):
1. Engine swaps for non-original motors incur significant additional time and funds to make them right on top of the cost of the replacement motor.
2. You need a fair degree of engineering experience and equipment, or the contacts and money to do the work for you.
3.The new engine will need either rebuilding or checking over at the very least.
4. Bespoke engine mounts need to be fabricated front and rear (plus most probably a head steady) after getting the motor positioned so it will operate correctly.
5. Oil tank manufacture (or purchase) and siting if moving to four stroke.
6. Fabrication of an exhaust system that both fits and works accordingly.
Aesthetically get 4, 5 & 6 wrong and at best the bike will look 'cobbled together'.

I definitely wouldn't cut the frame if changing motor, additional brackets can be brazed on where required for motor mounts, exhaust and oil tank fixing points etc. Far easier to remove later if wanting to go back to standard.

My advice, surprisingly boring, search long and hard for the con-rod assembly to get the original motor up and running.
Going to be much, much cheaper and far less hassle in the long run. Unless of course you really, really want a different powerplant..........

[Brian Catt]

Very valid points! Not knowing too much about the availability of 170cc parts, maybe the 125 is the way to go if those bits are obtainable.
On the subject of the Russian engines, one gent has done a lovely Cub insertion into one of the nice looking RTX frames. Just how he got it in is another thing.