spudulike

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

I would set the metering arm if not done already and then hold the carb up to the light, open the choke and turn in the idle screw until you see a very small amount of light around the brass throttle valve plate. The carb should be pretty close to going then. The other suggestions are a bit more complex and would be a phase two if the saw still didn't function like this. It is always worth doing the obvious and easy things first and then progressing to the more difficult if the easy stuff fails.

Oh dear, was alcohol involved in this? Once got a Stihl 039 in bits from a customer on the IOM who quaffed a bottle of burgundy, took his saw apart and woke up the next day with total loss of confidence. I rebuilt it but had two strange round bits of plastic left, I asked the customer what the hell are they and he said thank the f#£k for that, I also was working on my HiLux that night and have been looking for them everywhere!! What a life!

Thanks, a bit of a shock when someone that age dies!

I sorted a couple of his saws and sorted out an eBay pickup for him as I was close by. A good fella, had a good chat when we met up. What happened to him?

OK, shoe retaining spring has taken out that elbow I was talking about in an earlier post. Looks like you have it sorted, all good and not to££££.

And stick your tongue on it to test it

They sometimes screw in to the coil, others are potted and that is an issue which means you will need to find a way of splicing and joining a new piece of HT line in.

I would make sure the spark plug spur and cap are reassembled and see if it cures the issue. It can be a bit of a job but worth trying before writing the machine off!

You need to strip the clutch drum and clutch off, look at the area under the clutch and see if there are any obvious signs of cracks or wear. These 391/390 etc have a strange arm that pushes in to the oil tank union and connects up to the oil pump. It is possible the seals on the arm or the arm are damaged. The crank seals will NOT be an issue, there is no chain oil behind them! Frammos idea of pumping the tank up a bit is a good idea, easier on the saws with rubber pickup pipes but possible by pushing a bit of big fuel pipe on to this arm union connector (you will recognize it when you see it)! Sometimes you can fill up the oil tank with Petrol/diesel and if the leak is bad, it will come out a lot faster making it much easier to see. Not much else to recommend, I wasn't being funny in my earlier post, sometimes it comes down to strip and diagnose. Damage through a mechanical failure rather than wear are difficult to diagnose unless it is a common failure!

Glad it seems to have worked out OK. Thanks for letting us know.

Cake.........what a life

2014 when I ported it, not bad VFM in my book

I believe that Zama use a UV cure on their latest carbs. I have tried many substances, none using king size Rizlas I hasten to add!!! Cyanoacrylate, nail varnish and the rest all get degraded by petrol. Seal All is about the only stuff that doesn't fall out. I use any sealant in very sparse quantities so it doesn't fall out and cause later issues. The carb manufacturers recommend not using sealant at all since the increased use of Ethanol......... A bit of a holy grail is this subject!

Just strip it down and see where the oil is coming from!