spudulike

"Rivet".....put your glasses on old boy.......they are on your head

Possibly a 625 but could be a 630, both pretty much the same....Serial plate is missing so would need to look at the cylinder to be sure. They are good Pro saws

Damn, there goes another of my little tricks

It would help if you stated why you fitted a new carb kit and purge bulb. If the saw was a non runner then ADW is probably correct. It is possible you have installed the carb kit incorrectly or even fitted one with the purge holes missing. The purge should suck on one side and blow on the other. Easy to test with a short length of pipe and a cup of fuel.

It has been taken down, I think our work is done....may even be someone on here! Good job!

ADW is of course, correct....I use helicoils or Stainless inserts but would use helicoils on a 10mm repair. My recommendation - use a decent tap - I use Vokel and I would attempt to use a pilot nose tap as if you have enough thread left, it eases the tap in and getting it straight is damn important. If you use a cheap crap tap....you may as well save your money and throw the cylinder away now! A helicoil needs a well cleanly cut receiving thread. If it is knobbly rough and poorly formed, you will get poor heat transfer and it may even pull out giving you a bigger headache. Probably easier to take the cylinder off but if you are precise and catch all the swarf, I have done successful repairs without stripping the engine. Here is the tap you need (Haven't checked best price). You will need a bit of thread left in the hole to receive the tap but it is your best option. M10 x 1.0 Helical Pilot Nosed Repair Spark Plug Repair Tap | Engineering-Supplies.com ENGINEERING-SUPPLIES.COM HSS-G Spark Plug Taps Pilot Nosed To suit wire inserts ISO (6H) Tap tolerance ISO 1 (4H)

Sounds like you have been through a hellish time but you did right by your mother and when you get over her passing away, you will look back and reflect on the fact you did all you can and you will gain strength from that fact. In time you will remember the good stuff and laugh again.

He has some other cheap Chinese saws for sale but this one has the real stickers on it. I think it may be Zomax rearing its ugly head again! Caveat emptor!

Not far from me, perhaps I should go and see it I tried to report it but eBay have changed their reporting process and there is no easy way to say someone is selling a fake piece of shyte anymore! £260 for a non working bit of crap that cost £60 new.....some people must be dumb.

When I first got in to the porting thing, I did a lot of tests on my 357 with 8 pin, narrow kerf, 7 pin narrow kerf and standard 1.5mm gear. The 7 pin was faster on anything over 10-12" and the narrow kerf was 15% faster than the 1.5mm chain on the same rim. It really made that difference but it is obviously a compromise on strength in the cut so if you are mostly doing heavy forestry, it may not be for you but try it if speed is your thing. I tried a ported MS200t on a 1/4" pitch recently and it was completely bonkers unstoppable in the cut, the revs barely dropped in the cut under load! You just give up a bit of chain/bar strength - more chain tension adjusting etc!

Could just be the old shyte in the carb gauze strainer again. Worth checking the pump diaphragm as well, those flaps do tend to perforate sometimes. The bloke did say the compression was good...seen that beforeworth checking as well!

This may help, it states the clutch should be 86mm in dia. 050-051-075-076 Service Manual.pdf

If I had it, I would measure the clearance between the clutch and drum....a cheap set of metric feeler gauges will do this and look for 1mm+. I sort of suspect that the clutch springs are letting the shoes out too early and allowing the shoes to contact the clutch drum. The springs should keep the shoes in until 3000 - 3500 rpm before allowing them to drive the chain. Typically this issue is always down to worn, slack or broken clutch springs but can't be sure on yours until you confirm the clearance - someone with an 050 or 051 could confirm this clearance but would would need consideration for worn parts. The rest of the running issues - the saw should have enormous wrist breaking compression - if you measure it, expect 170psi+. Fuel systems are usually the next biggest culprit on old machines and then the HT system. Just a case of working through the machine bit by bit.

The clearance between drum and clutch looks pretty tight to me, especially on the laft hand side. The trouble with the clutch being aftermarket, you cant be sure it isn't just badly made or the clutch springs are poor - They usually are pretty iffy at the best! Your carrier (Centre boss) arms have a large gap between them and the clutch shoe. Looking at the IPL, it would seem that the arm usually extends to the shoe like the attached pic. Have you got the old clutch to compare? Does the clutch drum spin freely as it is without the machine running. Have you tried putting the bar on, starting it up and resting the chain on wood and blipping the throttle so you get a bit of friction action between the clutch drum and clutch? By doing this, you may take off any flash on the castings. I have just measured the clutch to drum clearance on my 181SE Husqvarna, it measures 1.2 - 1.3mm so you should expect very similar. If you are clever, you may be able to see where the shoes locate to stop on the carrier and lightly grind the surface so the shoes sit deeper making the clutch a smaller diameter. I would measure the gap you have and then decide the best course of action. You really need 1 - 1.5mm for it to work well. If this is OK, the clutch springs are best swapped out with OEM ones or just get the OEM clutch.

Push it back in to place...years left in it

You can't just ask "will it need retuning" as we have no idea where your saw is maxing out to. The very least you can do is to open the H screw out to the limiter but I have found many 460s and 361s over revving as they have loosened up with age and have had to pull the limiter to get it right. The only way anyone will know is to measure it at max revs and to retune it as and if required. Anything else is whether you will get away with it or not long term.

OK, from what I am reading, your clutch is aftermarket and 84mm diameter, the clutch drum is 85mm giving only 0.5mm clearance clutch to drum - this is far to small with 2mm being more normal. This is most likely the issue. You mention a 82mm clutch, this will give 1.5mm clearance between the clutch and drum which should work OK as long as the crank thread is the same. Aftermarket parts can be a bit hit and miss but the clearance is far too small - a photo of your clutch may substantiate this.

BTW, were the clutch and springs new and OEM? If you are using old springs and they are worn or slack, it will let the clutch spin the drum at idle speed.

If I am reading your post right, your clutch has an OD (outside diameter) 84mm and the clutch drum ID (Inside Diameter) is 85mm. If this is correct, you should have more clearance than 0.5mm around the clutch, more like 2-3mm. The 404 clutch should be part code 1111 160 2003 The 404 7T drum should be 1111 640 2002 The IPL is on this post...it may help Alec.....it is a centrifugal clutch as the force of the clutch shoes is outward, centripetal.....not heard that since A level physics...is inward force hope all is well with you BTW..long time....... 050 051 IPL.pdf

I gather he has a nice line of alcoholic beverages as well!!

Glad it worked out OK. Possibly wasn't positioned correctly last time it was apart.

2nd hole as per the pic (throttle slightly open)

Funny, so did I for a bit!

Sorry, not an area I would go to and I would personally think a muffler mod and your ignition advance would give you the easiest bang for the buck. If you know a little, measure the current squish with soft solder and if you have VERY close to or 1mm or more then the base gasket removal (replace with liquid gasket) is on as long as the original gasket is 0.5mm or less. These three things are relatively easy. If you want, just PM me and I will give you a few tips on simplifying what you do. The best mods are often some of the easy ones - do what gives you the 75% of typical gains from what is available - don't chase the last 5%....you aren't Sir Hamilton or Crashtaphen!

As ADW said, part of the CST check is the throttle solenoid position at full speed and idle on both Battery and Petrol equipment. Any dealer or outfit with access to CST will be able to do this check relatively easily and advise. I would agree that the throttle may be holding itself open with an ingress of chip or piece of bark etc. You could check this out beforehand if able.