spudulike

350s don't have top cover clips. The bottom end is also plastic rather than being of vertical split crankcase design! The top end isn't a 346 and the early 353s didn't have purge bulbs same as the early 346XPs!

50:1 is fine, make sure it is sparking OK, these old saws are a bit temperamental and have a habit of killing you trying to start them. Vintage saws need to be owned by people that understand them! My McCullochs have a screw you take out of the carb so you can tell when the fuel has been pumped in to the carb. They ain't like modern saws.....but are fun once going!

Yes but is it fixed yet, failure isn't an option, death or glory......!!!

I think this is what you need! XECCS2511TES20161024151747.pdf

Bloody hell, just get on with it man, sleep is for wimps, there are 24hrs in the day........failure is not an option I was saying to the wife the other day that you forget how much knowledge you acquire over time and it is only when you tell someone how to do something you think is quite simple - fit a bar and chain for instance, you realise some know nothing and how much info you have accumulated.

No......but......... no rings it would make around 70psi with no rings and combustion would be impossible. Sometimes the subject matter is near ludicrous but I guess others have little to no experience. The rings will be there but being a different colour, may look like they are missing. I think the OP may never come back to confirm!

My first suggestion is....put your fecking glasses on, the second is.....shine a fecking torch down the exhaust port!!!!!!!!!!!!!! The saw will not make compression without its rings, you think they are not there....they will be. I have dropped one ring on some Stihls to allow port modification, not the 260 but it does work and well.

I think it is time to get this sorted - the compression and piston condition must be good to start with - if you haven't, pull the muffler off and look at the piston - a pic would be good. When you pull the saw over slowly, as the piston goes through its compression stroke, does it feel nice and spongey or is it just too easy and slack? If you lift the saw off the deck with the recoil handle, does it just tumble downwards or stick for 1-3 seconds on each compression stroke (TDC)? If that bit is OK, it is likely that you have enough fuel for idle (low speed circuit) but not enough for high speed running (High speed circuit). If you haven't...change the fuel filter, it DOES make a difference. Then try the low screw on 1.5 turns and the H screw on 2 turns out. The saw should at least pickup on these settings. If it doesn't, try H screw 3 then 4 then 5 turns out - note any differences and come back to us. If still no joy, take the H screw out and give it a good blast of carb cleaner and reassemble L 1.5 turns and H 2 turns and try again. If still no joy, there is a slight possibility the check valve is stuck shut - when blasting the carb cleaner down the H screw - look at the end of the check valve in the carb bore and make sure the cleaner is coming through the nozzle in to the bore of the carb (Middle bore leading in to the engine). Worth checking the fuel line for splits - plug one end and blow down the other end - I use a Mityvac pump for this but assume you haven't got one! If that doesn't do it, it is a real oddity!!!! BMP - spot on on accelerator pump issues, air gets past and is then injected in to the check valve giving all sorts of idle issues BUT....high speed generally works OK and it isn't a sudden issue. A stuck pump (it happens) gives a very flat pickup but the engine will still rev out after a bit of feathering.

Damn, you found the family get together video!!!

As I said, it may be to kid a purchaser he is getting a 346XP as the saw model, year manufactured and serial are all on this plate! I would say it being hot is more likely TBH!

Oxford Dictionary I believe!!

The 353 and 346 are pretty much the same machine but with slight differences to port timing and piston diameter so difficult to tell what you have. Your saw is NOT an XPG so that recoil cover is NOT original. The clutch cover is a Silverside off a "New Edition" 50cc 346XP or XPG so NOT original. You either have a 346XP with a 353 cylinder and piston OR a 353 with a 346 recoil and clutch cover. My hunch is that it is a 353 made to look like the more popular 346XP - possible the serial was removed to fool you or it is hot! I base that on the fact the recoil cover and clutch cover are non original and a 353 top end would be a difficult one to get hold off in comparison to a 346 one. The 353 is OK, not as fast revving but probably more torque.

That plate should be almost circular on a 346 and with a sharp defined edge, not a cast bevel.

For the record - I have never stuck a 353 top end on a saw - not sure I have even had one in....a little bit rare due to the barnstorming 346XP!

OK, call me a loon, a freak, a dipstick, master of the universe but.........just try winding the H screw out a couple of turns and try again. The symptoms don't strike me as being accelerator pump or check valve unless the valve is stuck shut!!

It isn't an XPG, just reviewed the photos and no switch!! Something looked odd about that cylinder, just checked my 346 and reckon that top end is a 353 as the top stamped plate looks a completely different shape. Perhaps the recoil and clutch cover have been changed from a 346!

XPG means heated handles and there should be a switch near the top AV mount from handle to cylinder. The cylinder is 100% OEM which is good, the serial plate is near impossible to remove as the rivets are one way - I have fitted short bottom ends before hence I know they don't come off.....I check all saws for serials when they come in - all missing serials get referred back to the customer and noted on the invoice as I run a transparent business! It does look dodgy to me and surprised the top end is OEM. Interesting to know if anyone I have done this conversion on has had their saw stolen!

The only thing I would say is that drifting the check valve out is sort of simple but it is fairly unlikely to be the issue. It gives a saw a real lumpy pickup and massively over rich running - I do around 2-4 a year and isn't a common issue. On the accelerator pump....I actually agree with what you say 100%, if the C1Q carb is over 7 years or very heavily used then yup, it may give issues and I replace them as any decent tech will rather than replacing the carb and charging the customer £130 for the techs lack of skill! Each saw reacts differently to a bad pump, MS200Ts have a completely unstable idle, rising high and then dying, MS201s do run with dodgy pumps but generally I have found that they are stuck rather than worn giving a flat unresponsive lag to the throttle. Replacing the pump and check valve is relatively easy after you have done 2-3 carbs but they aren't what I would call easy for the uninitiated and can go completely wrong!!! What is the current state of the saws running, this banter has been going on that long, I have lost track of where we are now

Highly unlikely, it is probably a 50cc aftermarket kit on it but a pic of the top of the cylinder will tell us more. The best outcome is that it is an OEM top end, done a few like that and never needed the primer in this setup.

Stubby is talking about a 357XP....it is his age and he gets excited....easily The saw looks like a 45cc one with the 50cc Silverside side cover on it to me. The decomp valve is a bit strange as most 45cc ones that I have had in have had no decomp valve so it most probably has a 50cc top end on it. If you take a pic of the top of the cylinder including the little plate near the plug hole, we can tell if it is OEM or not. The bottom ends of the 45cc and 50cc machines are pretty much the same, the fuel tanks on the 50cc ones have provision for the primer return hose but a 45cc machine with a 50cc top end is a valid modification. The muffler is a 45cc type as well as the parts Stubby mentioned.

I use their brake cleaner and carb cleaner. Happy with those products as they work well.

Those trimmer heads need greasing every 25hrs, any grease is better then none and I use lithium in all gearboxes and let the customers know to grease every 25 hrs!!! It is lack of grease that knocks these gearboxes out and not the incorrect grease!

When you say the saw is still difficult to start, is it still kicking back severely or is it just not starting well. Both will have entirely different approaches to resolve!

Metering arm - get a rule and lay it over the flat surfaces the diaphragm/gasket sits on, the metering arm should be 0.5mm - level with the rule and no higher - get it too high and the needle valve will leak, too low and no fuel will flow through.

Can someone ban Eggs from the forum, please.....quick.......... this could be a pandemic