spudulike

It is always easier to start rich and work down than to start lean and seize the engine although that probably won't happen!

You can only see the damage if a needle is missing. You generally feel too much play on the clutch drum and change the bearing when it happens.

Glad you are enjoying it Patrick, I dd warn you it will be a bit of an animal:thumbup:

I recently had two on and one had no rollers in its clutch bearing, never seen one that bad before! I was being factual and pointing out what I had seen rather than slagging the saw off!

Looks like you will have to work it out the hard way then:001_rolleyes: Lots of general info on this site and Arboristsite.com - all you need to do is put it all together in to something that works and doesn't kill the saw:thumbdown: Reliability is sometimes last in someone's mind when porting where it should be in the forefront!

The issue is with the fibre glass in the clutch needle roller bearing breaking down, making the clutch drum loose which then wears through the oiler arm. I don't know what the ultimate route cause is but would try to find a steel caged needle roller bearing of the same size which I believe will last longer especially if it is lubricated regularly. If the clutch drum is still loose with a new bearing, the drum may need replacement as well.

Compression is a funny old thing - we are talking secondary compression and not primary (crankcase) compression! I have had a few engines that have made good compression (150psi+) and severely lacked power, on inspection I have generally found worn piston skirts causing the problem. I have had other low compression saws I have tried to up the compression on by dumping the base gasket and had a good increase in compression but still low on power output. The summary to all this is that if your saw is down on compression and/or power then a "quick bodge" isn't possible on a worn piston. The piston needs more than a decent ring to give good power and the skirts being a good fit do more than stop piston slap and aid low down torque and ultimate power!

Probably worth pulling the carb, checking the impulse line, the fuel line and filter then checking the pumping section of the carb for the "shyte in the gauze strainer" issue and then take the H&L screws out, bit of carb cleaner down them and set at 1&1 turns out then check the diaphragm and metering arm height. I usually pressure check carbs to ensure the needle is sealing but in absence of this, put it all back together and try - 40 mins work and should get it singing:thumbup:

You are checking the crank seals, inlet manifold if rubber, impulse line if rubber and all gasket joints - usually cylinder to crank and the crankcase vertical joint....and decomp valve if fitted. You do this by sealing the inlet and exhaust port, sealing the impulse if separate and then attaching a holed spark plug hole adaptor so a pressure/vacuum gauge and pump can be connected - this can be a purpose manufactured bit of kit or home grown like mine - the pressure you need is 10psi and the vacuum is -15 inches of Mercury.this There is no real alternative to doing this correctly - it is best to get zero leakage on the engine even when rotating the crank slowly. A water and detergent mix can be painted over suspect leaking parts to see if it bubbles. I would have thought that the airvane would have stopped the saw over revving but may need checking again. Seals tend to last for 5-10 years + but you may have an issue somewhere.

Yes but it sounds like you are using fluid under pressure rather than air under pressure and then vacuum. Different leaks behave differently under vacuum and pressure. Holding on to revs is a classic sign of a seal leaking under vacuum FYI. You should check that the throttle valve is fully closing and the closing spring is still working well, also make sure the throttle linkage is free moving and loose when the throttle is closed. Also try manually shutting the throttle valve with your fingers to see if the engine revs drop if you push it closed. I am not familiar with the 090 but doesn't it have a aerovane rev limiter on it - the Contra I worked on recently did! the plug going white will be down to a lean mix and over-revving!

From what I have seen in my workshop, some of the sharpening is laughable - mostly on home owner saws though. Everyone knows you get the best edge with a grinder:lol: ...that's for Treequip to comment on - got to keep the old boy busy:001_rolleyes: The angle of the cutters usually become more acute and pointed as it is easy to file the edge rather than the hook! A favourite of mine is a sharp chain and the raker depth gauges being to high so the chain polishes the wood! If you are getting good chip out of the saw, all is good, personally I do it by eye and use a Stihl depth gauge for the rakers. The grinder comes out for the mullered chains where filing would take forever...even with a new file and good technique! The cutters can always be lightly dressed after with a file as required! People also forget that the bar is a supporting element to the chain, too much roll in the rails and it will allow only one set of cutters to work or even none of them in bad cases. I have seen many with one rail 0.5 - 1.0mm below the other:thumbdown:

Just purchased one for general cleaning, drilling and porting where space isn't a constraint - already got a Silverline dremmel type rotary tool with the flexible drive so should be useful - £25 is nothing and if it lasts a year or two, it will have paid for itself many times over!

I tend to buy any thin jaw pullers I can lay my hands on, the few quid they cost is pulled back damn fast when pulling a flywheel takes minutes instead of hours. It is worth looking on the bay for Sykes or any other older manufactured kit that was produced when kit was made to last. One tip is to not just keep turning the screw but to get torsion in it and belt the end with a hammer - the jolt frees things up generally last time I fell ass over tit when doing a 395 as it seperated and went from lifting the weight of the saw to just the flywheel:blushing:

My woes have just melted in to insignificance. Hope you bounce back but sympathies to you and your family on the meantime.

Well don't look at me, the only carving I do is the Sunday joint and we aint talking spliffs:lol: We actually thought you did well last year and were touched that you gave the owl away - nice touch:thumbup:

Get your dad to put the rubber gloves on and you can bend over:blushing::lol: I wasn't even thinking of you Matty, the one I have in now makes yours look like new:001_rolleyes: Hope it is all going well where you are now - whose going to do the carving at Ashwell show this year?

I know many will have other pet hates but here are mine: - 1) Home owner equipment in to service and the owner saying that there can't be much wrong with it:thumbdown: With a sigh I say, just buy me a crate of beer:001_rolleyes: 2) A box arriving with the saw in bits where the dealer or owner ran out of talent or the inclination to fix the saw:sneaky2: You NEVER know if all the bits are there or if any part is busted and all that oily saw-dusty crap that is all over the saw - think if I owned saws for professional use, I would own a compressor and clean them out once in a while! 3) The old saw with an attached owner saying "Don't spend too much time on it, I don't want to pay too much".....tough, old saws should be owned by owners that covet them and look after them in their old age. Old saws always have perished fuel lines, need carb kits, have buggered sprockets, are covered in antique musty smelling wood chip and are generally past it. Am I some sort of Magician turning crap in to gold - it all takes time and is generally MORE time consuming and needs greater skill and perseverance to resurrect these saws:scared1: Rant over - can someone send me a nice clean saw to fix for a change:001_rolleyes:

Don't we know it:lol:

Thats the High speed check valve - a one way valve that acts like a jet for the high speed fuel flow - it goes straight through to the carb bore if you look on the inside of the carb bore.

Evinrude Two-Stroke V8 is a Hot Rodders Dream - Road & Track Quite agree:thumbup:

Thats a nice bit of kit - I would imagine it is two TZ750s bolted together and nice expansion work:thumbup: Sounds glorious:thumbup: Just looked - it is an Evinrude marine 3.5 litre boat engine

If you do find that flange has worn through, check the outer crank seal for damage to the outer seal - I have just repaired a saw that had taken out the seal in this manner - fourtunately the owner caught it early enough not to seize the saw:thumbup:

For the record, the 357XP oil worm drive pinion has a flange around the front of it, this locates on a step on the crank shaft and stops the gear riding in and rubbing on the seal and also keeps it in mesh with the clutch drum:thumbup: Look at the photo below and you will see the flange- I am talking about the one inside the central hole and NOT the large outside one!!! If yours is missing then change the part - around £10!!

If the ring isn't moving freely in the groove as it sounds like it isn't, try a bit of brake cleaner or solvent on it and see if it frees it, if id doesn't, then let it dry and then give it some heat with a plumbers lamp and see if that does it. I had a blower like this and managed to free the ring in this manner and get it running again. You could try a heated ultrasonic cleaner as well, if you have one!

Nice one