non genuine piston and pot - any advice?

[Chris Sheppard]

bought a very lightly used 357 last week that I think has been run without 2 stroke oil, given that there was half a tank of very clear fuel i nit and the front of the piston is fairly heavily scored. I paid not a lot for it and have worked on the basis that it's goign to need a new piston and pot and even if I put a genuine one on it'll still be a sensible priced saw.

 

I'm not averse to trying out non-genuine parts and wondered if anyone had tried any of the non-gen piston and pot kits off ebay and if there were any to particularly avoid?

 

Another question, it's been a long time since I've rebuilt one that's scored a piston enough to grip the piston ring solidly so can't remember the answer - would I still be able to get it to fire, even if not actually start or would the compression be too low (it has one of those stupid auto decopmpressor things on it so without tools I can't blank it off to try and get it to fire) There's a spark and fuel's getting through, but as I don't know whether it was scrapped because it wouldn't start or because it stopped.

 

Quite looking forward to getting this one fettled as we've some decent Pines to be getting on with and the 372 likes a drink

[agg221]

Spudulike is your man really, but he's away this week.

 

I have used a couple from Garden Hire Spares - they're on ebay but also have their own website. So far they've been excellent. There are real people on the end of the phone if you prefer it to the website, and I've never had a delivery later than next day (even when I ordered at 3pm on a Friday!) In terms of quality, they get the significance of A, B or AB sizes and offer a 1yr guarantee. With the first one I bought, for an 044 on a mill, I pointed out that it would be working hard and they said that didn't worry them - so far no problems and I've had the muffler off to check. Compression (measured by gauge) was good too, so no sizing issues.

 

I know Spudulike uses the ones from Mr Solutions on ebay too, and has had no quality issues that I'm aware of, but I haven't found him so easy to get hold of (I did buy an 051 pot and piston from him as he seems to have some of the more obscure stuff, but I haven't run it long enough make comment yet).

 

In summary, I reckon they're fine. They may wear out a bit quicker, but genuine is five times the price and I bet they don't last five times as long!

 

With regard to your other question, it really depends how bad it is. If it's bad, no it won't fire. If there's damage to the pot as well as the piston then it almost certainly seized, which I would lay odds on as the reason for scrapping it.

 

Alec

 

p.s. don't throw the pot away unless you can clearly see that plating has been ripped off of it - I strongly suggest dropping Spudulike a PM as it may well be recoverable at a lot less cost than a new one.

[Chris Sheppard]

Nice one, just the sort of thing I was hoping to hear

 

I've still not got as far as pulling the pot off yet, kinda chucked it all in the box and went before the guy could change his mind, had a quick go at getting it to go and then chucked it all in the corner until I get chance to have a look at it.

[spudulike]

Agg21 has a GHS one fitted on a 046 I think it was - done some hours on it milling and it all looks fine with decent compression.

I always try to salvage the cylinder if I can by removing the transferred aluminium and then fitting a new piston.

Don't try starting it, you may kill the cylinder.

The EPA models are bad for the decomp failing-plug the crank case connector and fit a standard decomp valve plus make sure the metal carb boot ring mod has been done.

[Chris Sheppard]

Agg21 has a GHS one fitted on a 046 I think it was - done some hours on it milling and it all looks fine with decent compression.

I always try to salvage the cylinder if I can by removing the transferred aluminium and then fitting a new piston.

Don't try starting it, you may kill the cylinder.

The EPA models are bad for the decomp failing-plug the crank case connector and fit a standard decomp valve plus make sure the metal carb boot ring mod has been done.

 

Just the job - was hoping the decompressor could be bypassed and a normal one fitted.

 

Will get it in bits and report back

[spudulike]

Still alive and kicking - on the blackberry!!

[spudulike]

Just the job - was hoping the decompressor could be bypassed and a normal one fitted.

 

Will get it in bits and report back

 

Just make sure the crankcase connector is plugged and airtight - otherwise it will fry another piston!

[spudulike]

One last thing - make sure the non original Cylinder has CLOSED ports not the cheaper open ones, a GHS one I got for a 346 had open ports - not so good, these are Transfer ports we are talking about - you could look at Arbireland on ebay - their 346 kits look good

[elfinwood saws]

yes go for it fitted lots of these kits from GHS and not had any problems

[Chris Sheppard]

finally got round to taking pot off tonight, see attached pics.

 

Gettign a bit confused now though - piston is about 46mm and the pot a tad bigger, now on ebay I can find 46mm piston kits and also 47mm piston and pot kits that says they'll fit and give a bit more power too - does that sound feasible?

 

also, I'm gonna sound a bit daft here but what am I looking for to determine between open and closed ports?

 

The pipe from the auto decomp goes from the decomp to an outlet a bit lower down on the pot, is it as simple as fitting a normal pot with no lower outlet and bunging in a normal decomp? Can't see anythign obvious on the crank case.