Megatron

How does the saw cut out? Instantly or does it "load up" first. Sounds as if it may be running too rich on the idle circuit. Like Stubby says it is most likely the act of deactivating the chain brake. When a saw is left to idle, if it is slightly too rich on the L screw, fuel can puddle in the crankcase. When the saw is tipped (which it usually is when deactivating the brake) the puddled fuel will mix with the fresh charge in the crankcase making it way too rich and the saw will stumble and die.

Forgot to say; -either install the intellicarb end cover from your old carb or block up the outlet on the air filter.

Yes, it can be done but reliability would be my biggest concern. The best carb replacement, IMO, is the Walbro WT-215 (fully adjustable). Used on older 1123 series saws (025 etc). To make the change all you have to do is; -drill out a new position for the impulse passage (already indented on the carb where you have to drill). -block off the old one with JB weld etc -drill holes in the plasic shrouds to enable adjustments. -bend open the throttle linkage a little to enable the throttle plate to open fully. So you could now increase the size of the muffler outlet and richen up the carb accordingly. There is no easy way to reduce the squish on the clamshell saws, depends what equipment and time you have available to you. Do you know the basics of porting? As I mentioned in my opening line, reliability would be a concern. The crankshaft isn't that heavy duty, the conrod isn't forged and the big end bearing is cageless rollers.

The 017/018 never had an adjustable H screw. The early 017 saws only had idle and low speed screws. Then they were installed with the BIS carbs (balanced idle system), with only the one, LD, adjustment screw.

What colour back does your current filter have? Sounds like you have the wire mesh one which is now only recommended for use in extreme wintry conditions i.e. falling snow. You want the HD2 filter, looks like this; Or do you have the older HD set up with the prefilter?

Diesel chainsaws have actually been tried before; Chain Saw Collectors Corner Haven't heard about anything diesel related on the horizon but fuel injection is already here... Stihl have recently released the TS500i cut off saw, which has fuel injection; STIHL Online Catalog

Tank vent. It doesn't have an impulse hose, rather an impulse passage. If you did a pressure test surely you must have known? IPL can be found here

365 Special or standard? What year? Parts lists can be found here; Download Manuals - Husqvarna Forest Equipment Operation Manuals

Do both carbs have inlet needles with ridges (I presume you mean grooves) in them? If the new carb kit doesn't fix it it will likely be the main nozzle check valve at fault.

Oh I see. But for air to reach the inlet needle (and then through the main nozzle into the bore) from the impulse passage the pump diaphragm and/or gasket must have been leaking. Which might explain why it ran lean.

What pitch sprocket does it have at the moment? 3/8P or .325" The largest offered from Stihl for the 025/MS250 is 18". I don't believe any other manufacturers produce a longer one that will fit. 3005 000 4817 for 18" 3/8P .050" 3005 008 4717 for 18" .325" .063"

I agree entirely. Check out this thread; http://arbtalk.co.uk/forum/chainsaws/31389-can-you-spot-fake.html

I would have removed the flywheel before removing the top cover to check the oil seal and also the sealant between the pan and the cylinder. The top cover is relatively easy to remove, harder to install. It does help if you remove the brake handle first though. Looks like an early model, can't be certain from the pic of the date on the sticker. But given there is no decomp and the old style tank vent it looks like a 2000/2001/2002 model.

How does air leak out of the carb if you are performing a vac/pressure test on the crankcase?

Keep pulling until the reading on the gauge stops increasing. Really a compression reading is only any good if you have another known good saw (etc) to use the same gauge on to get a reading to compare. The pressure in the gauge after the first and second pull are of little relevance as they depend not only on the pressure in the combustion chamber but also the volume, which obviously varies for different model saws. You only want the max reading. Throttle position will play little part, if the intake is obstructed the air will be drawn from the exhaust. However, you should remain consistent in your method.

Anything you do to the exhaust will void Stihl's warranty. Also you will likely need to retune the carb to maintain optimum fuel to air ratio and your carb will likely have a limiter cap on the H screw which may need to be removed. If you do decide to change the direction of the exhaust, the easiest way would be to get an 023/025 muffler and remove the deflector and make your own to direct the exhaust the other way. Aspen is a good suggestion also.

(North America and Europe) -051 was allegedly released in 1972 and had points and condenser. Switched to electronic ignition in 1974. -075 released in 1974 never had points and condenser. For 051 saws from machine number 3 001 400 exclusive use was made of the breakerless (transistor) magneto ignition system. -early versions of the 051 and 075 had top oil caps and no chain brake option due to not having crankcase mounts. -later versions of 051 and 075 had side oil caps and option of chain brake. -originally both 051 and 075 had the fairbanks-morse friction starter, 051 fuel tank smaller than 075. However, due to the longer production run of 051, after 1980 the 051 shared the pawl starter and fuel tank with the 076. -076 released in 1980. Mainly sold as 076 Super in the US and discontinued in 1986. -084 released 1985 -TS510, TS760 share a lot of parts with 051/075/076 and had considerably longer production runs Al is right, parts availability varies greatly between the US and the UK. Most 076 parts can still be bought over here. There are a lot of 075 ignition parts that are NLA though. Trigger units, flywheel, fuel tank etc. However, they can be replaced with 076 parts, trigger units with either the Nova II etc or the updated OEM module. Parts availability for the 084 over here are bad and even worse in the US I hear. I remember looking up when a lot of the 084 parts were NLA from the factory a while ago and posting on here. A lot of wear parts are shared with the 088/ms880 and are still available. IMO the 075/076 was poorly built. -prone to holes in the fuel tank. -the same part of the crankcase is virtually always broken underneath, as a result stones get in and bust off flywheel fins etc. -if the seals leak on the oil pump end up with bar oil in crankcase. -early trigger units (under flywheel) had high failure rate due to heat. -prone to vibrating the intake tract bolts loose leading to air leaks. -takes longer than other Stihls to pressure/vac test.

A lot of Stihl saws won't even have a sticker with a date on! Before the early 1990s you're out of luck, they will just have a safety warning sticker, no date. Besides I wouldn't trust a sticker anyway, easy to swap chain brakes and often the sticker is missing. Lots of frankensaws on ebay. Often lots of port dimension/timing changes occur throughout a saws production which have a noticable influence on performance. Along with ignition changes, intake tract changes, exhaust changes etc. A 10mm 044 is a completley different animal to a 12mm one.

Oh, ripping chain. Some other time

My take on the Stihl chains; First of all two basic types; Rapid and Picco which determines the chasis height. Picco = low profile. ------------------------------------------------------------------- Now 4 basic different versions which determine cutter shape; chipper tooth = Standard (no longer made by Stihl) full chisel = Super semi-chisel = Micro carbide tipped = Duro ------------------------------------------------------------------- Now is it narrow kerf or not? Narrow kerf = Mini (only applies to PMMC3) ------------------------------------------------------------------- Low vibration? Comfort = low vibration. Have a C stamped on cutters and arrow on cutters. For Comfort chains the cutting edges (side and top plates) and depth gauges are exactly the same as the standard vibration chains. The bottoms of the cutters and tie straps slope upwards at the rear. This clearance between the cutter and guide bar allows the cutter to tip back slightly and thus produce a shock absorbing effect. However, when there isn't a standard vibration chain available the C is omitted from the naming structure. (Still have C stamped on cutters and arrow on cutters). i.e. PS3, PD3, RMS, RD3 chains are in fact all low-vibe Comfort chains. -------------------------------------------------------------------- Low kick-back? 3 = low kickback. Humbed tie straps reduce vibration and kickback potential/angle. Stihl have used the number 1 or 2 in the past to denote low kickback. -------------------------------------------------------------------- The geometry of the cutters on RS and RSC chains are the same. However, RSK chains have a cutter geometry which promotes better chip flow and hence, cutting efficiency. K = Klassic. -------------------------------------------------------------------- Round ground or square ground full chisel? Square ground full chisel used for mostly for clean green softwoods, faster than conventional round ground. Square ground = L -------------------------------------------------------------------- Full skip, half skip? Full skip = F Two tie straps between every two cutting teeth. Better chip flow, chain speed and less sharpening maintenance than full complement. Half skip = H Alternate between one and two tie straps between cutting teeth. Properties between full skip and full complement. --------------------------------------------------------------------- Special application; RDR = Rapid Duro Rescue --> Fire and rescue RMH = Rapid Micro Harvester --> Harvester chain RMHS = Rapid Micro Harvester Special --> Significantly reinforned RMH chain RMS = Rapid Micro Special --> Carving chain

Yep. I'm thinking either the pawls or their return springs on the flywheel are damaged/not working properly. Or most likley the spring which stores/transfers the energy from the recoil to the flywheel is damaged.

Their is no date information directly put into a Stihl serial number. A dealer you may have some luck if the saw was registered but even that may be restricted to the country it was bought in. However, there is indirect date information and if you really know your stuff (like me ) it is possible in most cases to be able to get a pretty good estimate of the year of manufacture from a serial number. There are often quite big changes that have occurred through a saws production run that influence parts availability (OEM and aftermarket), reliability and performance. A few examples; -10mm vs 12mm wristpin on 044 -aluminium vs polymer flywheel on 066 -44mm vs 44.7mm piston/cylinder on MS260 etc. The changes are outlined in service bulletins and a serial number is given up to which the "old" parts will be used. (/from when the new parts will be installed)

Oh, for pressure and Vac testing I use a Mity Vac MV8500. Not cheap but soon pays for itself. Make your own flanges etc. Part number for the Stihl equivalent; 0000 850 1300 (pump only) £170 excl VAT!

... Ash; 357XP -Does it have either of the autodecompression or plastic boot clamp? -Cylinder might clean up and be usable, won't know until you try. Use caustic soda or hydrochloric acid to eat off the aluminium. Wear face protection, well ventilated area, gloves etc. I use a synthetic paint brush to apply. Wet and dry paper to finish. -Spring can be relatively easily replaced. Will have to remove the throttle shaft though which means the throttle plate also. When you remove the screw for the throttle plate watch that it doesn't strip the threads out of the throttle shaft as the end of the screw is splayed out, to stop it undoing. Similarly on reinstallation use loctite on the screw. -Find the IPl here; Download Manuals - Husqvarna Forest Equipment Operation Manuals BG85 - Did you remove the circlip or is that missing also? Looks like someone tore it down and then decided it wasn't worth fixing? Hence the missing ring and gasket. -Hard to tell about the cylinder with just a picture. It looks like the coating is starting to wear away. Has part of it has chipped off near the lower right transfer in your picture? Think I know where you could get a used OEM P+C for £35. -Breaking the flyhweel fins off the opposite side won't properly balance it but you might get away with it for a short while. Flywheel about £20 off ebay. -The rust on the bearings isn't good news, again hard to tell from the picture. -I can send you the parts list. IMO you would be better off selling the blower and using the money toward the 357

Why by private message?