Recent content by Sawrain

Electric start system details attached.

The charge regulator is missing/blown in my saw, I don’t plan to have the batteries charge when installed, I’ll charge them externally in a proper charger and pop them in when needed.

Yes, 21 Amps @ 14.6 Volts. As standard was likely only 16 amps, as the the batteries would have sagged to around 10 volts under load. Tested at 14.6V as I am considering LiPo batteries that would be in that area.

Current draw for anyone interested.

Thanks, Appreciate the info.

Hi all, Wondering if anyone has a 261 piston they can measure the dish dimensions on for me? As compared to the 262xp flat top piston.

Good Idea, collect it all here until we/I can make the spreadsheet we want. I have seen some good recourses over the years, but many seem to be dead links now, could be a job for the wayback machine Many thanks. Found these already collated recently.

Just wondering if anyone has ever put together a spreadsheet of carburetor models, with venturi sizes, intake sizes, choke or not, etc. Seems to be something I waste time finding each time I am curious about a saw, carb or swap. I have seen some excellent cataloguing of other information here...

Thank you, very nice to chat, petty we just have more questions. And thank you for the thoughtful discussion. Now I am wondering what experiments can be performed to confirm or deny any of the topics from today. A few thoughts on 4 stroking as well, but I really better do some actual work.

Think I need to attach a mass airflow flow sensor to a chainsaw intake and experiment, or just think about it for a few months. Appreciate the labelled answers.

I was thinking the same, good comment. Guess I need to state what I think 4 stroking is first, something like a combination of reduced scavenging effieicinay not clearing enough exhaust gasses and our simple carbs making an overly rich condition at high rpms, until it gets so bad that there is...

drf256 and myself were talking about the direct benefits of compression itself, how does squeezing your charge tighter create more power? I never meant to venture off to how does compression ratio effect cylinder fill. What is your take on how the dish Vs non dished piston effects the...

I will draw attention to my use of the word consider, it was easiest for this discussion. I 100% agree the the 261 cylinder has a larger volume at the beginning of compression, but at the moment of being trapped by port closure it was still fed from the same crankcase volume/shot, this is why I...

There are other ways to solve combustion instability problems though, better design, higher octane fuel, water/meth injection, mbt timing and so on. I am suggesting a direct link between compression ratio and power, one you cannot really work around, well apart from with forced induction. In...

I will offer an alternative explanation as to why higher compression ratios (within limits) increase power. Compression ratios are a, if not the fundamental factor in regards to an internal combustion engines maximum thermal efficiency. Higher thermal efficiencies extract more power from the...