Unfortunately I think this has turned into an Aftermarket vs. OEM thread.
It should actually be a "Crappy Quality Aftermarket vs. OEM thread". I think we can all agree that a good aftermarket kit has the potential to be a lot better than a crap OEM kit as many of us have seen.
The funny thing is that some builders have been quite happy to port and modify crappy OEM cylinders and get good results yet still tarnish aftermarket with the same old brush. With some of the comments I actually think it is more anti Chinese than anti aftermarket.
As mentioned if you are tidying up ports and doing some machining etc then there is absolutely no reason why a good quality aftermarket kit shouldn't compete with an OEM kit from a power and performance point of view. Yes there may be some squish and compression concerns with many aftermarket kits but those with their butts firmly planted on the OEM side of the fence seem to forget that many new Stihls and Huskys are coming with about 150psi from the factory anyway - hardly what you would call high compression.
if the same scrutiny was placed on OEM kits I think most of us would get a wise little surprise up our arses. I think we should also look around at the amount of OEM kits that have failed after porting and rebuilding. 9 times out of 10 it is not the fault of the kit but the way a circlip was installed or the fact exhaust ports were made too wide. I can't help but think if the same thing happened on an aftermarket kit the fingers would first be pointed at the kit and not the builder who quite simply stuffed it up.
There is however one thing that people are overlooking with aftermarket kits which I think is quite possibly the most important aspect and that is the lifespan of the Nikasil plating. I don't think anybody here can say that a Mahle P&C wouldn't be good for at least 1000 hours if looked after. I have seen early generation MS660 BB kits come back from test saws with only 100 or so hours on it and the plating is already completely shot.
These same kits also exhibited unusual ring wear indicating the bore wasn't square as well.
I can also say that a few of the 395XP big bore kits I have sold have gone into full time firewood cutter's saws and have many 100's (maybe 1000's?) of hours on them without a hitch. These guys have some sort of freaky genetic ability to wreck saws within minutes so that says something.
I do however think that the anti aftermarket aspect of this thread has turned into a bit of a witch hunt which has blanketed all AM kits as being crap.
If I had the time or even gave half an arse I could go down my shed now and take photos of every single aftermarket P&C I have simply to show that if you keep on top of your suppliers enforcing that you won't accept garbage then the end result will be better quality kits being supplied.
The fact of the matter is that when dealing with the Chinese you simply
HAVE to check every kit. If you don't complain and constantly keep on them then trust me the only result will be a decline in quality and a lot of time spent replacing kits (which costs
YOU money as you
WILL not get a refund from the Chinese!). The Chinese will start to substitute lower quality components the second you let your guard down - it has happened to me. I have learnt...
For the record good power can be gotten out of the better quality aftermarket kits. This is already being achieved on the quiet in the Australian racing scene. Another factor is the price - although I don't race it is for the good of the sport to make it affordable and get as many people involved as we can. The top runners are likely to always be running OEM as cost is generally not a factor and if money is no object then everybody would prefer to run Mahle etc. Also remember that in Australia an OEM kit and labour to fit it is a similar cost to you guys in the states buying the whole damn saw!
If you guys had to pay for OEM what we do in Australia you'd all be on the aftermarket bandwagon. The aftermarket kits I have sold at good prices would have kept many guys warm for winter when otherwise they wouldn't have been able to afford to get their saw fixed.
I can't find the photo now or even remember the customer's name but he had a 372XP that he straight gassed. He bought one of my big bore kits on eBay and emailed me about 12 months later with a photo of a big tree he was cutting up for firewood while his son was helping load the split wood. He actually thanked me 12 months later and said the saw was still running like new. Certainly beats getting abused
Also remember to replace the rings in any aftermarket kit if you want to ensure it is going to last. The one thing that we
CAN all agree on is that the supplied rings are crap
