What's on your bench today?

[spudulike]

Right - the 394 is now back together again, pressure checked which was fine, have run it up and it idles and revs fine, next stage is putting on a bar and tuning the carb which has been stripped and cleaned.

 

After 30 secs of running, compression is 150psi which is encouraging:thumbup:

[Nat]

That dark brown fluid is seizing juice:thumbdown:, the petrol has broken down the two stroke oil and left it with zero lubricating properties.

 

Hopefully the new carb kit will do it - I would check the fuel pipe, filter, impulse line (not sure if it has one - not had one apart) and the carb boot - if any are holed then replace them. Any sign of a racing idle and the crank seals may need replacing!

Good luck

 

No carb boot on these monsters - no AV!

Intake gasket was a bit poor so made it another - from a Stihl chain box

Fuel hose had a split, newie fitted and threw in the carb kit, rest of the fuel system checked out ok.

Running pretty well now, idles real slow - forever.

The rev limiter seems a bit overly keen (a wind vane works the choke on these) might look at a new spring for that

 

Sprocket has mega wear, so thats more expense...

Abused my £35 chain grinder with the .404 chain and off we go!

[Megatron]

No carb boot on these monsters - no AV!

Intake gasket was a bit poor so made it another - from a Stihl chain box

Fuel hose had a split, newie fitted and threw in the carb kit, rest of the fuel system checked out ok.

Running pretty well now, idles real slow - forever.

The rev limiter seems a bit overly keen (a wind vane works the choke on these) might look at a new spring for that

 

Sprocket has mega wear, so thats more expense...

Abused my £35 chain grinder with the .404 chain and off we go!

 

Although the carb boot/inlet manifold is not the more modern soft rubber etc which get holes in. They can warp over time causing an air leak, same problem with 070/090, 075,076 etc

 

The wind vane governor can be altered/stopped altogether. You can adjust the position of the end of the spring, hence, altering the tension in the spring and thus the RPM at which the governor kicks in.

 

If you have a problem with any of the bolts vibrating loose you can change them out for Torx ones which are serrated on the underside of the head to prevent such occurances.

 

Does the saw have a spur or rim sprocket?

[spudulike]

Just got the new piston in the MS460 - good compression but noticed the pressure was dropping 1psi per minute, bit faster than I would like so traced the leak back to the crank case seal behind the clutch - it was popping a little.

 

Gave it the soapy water once the oil pinion was off and bingo - it is leaking.....within Stihl specs but would be false economy to leave it so got new ones on order. Not what I wanted but at least it is a fault that could have caused the heat seize in the first place.

[swinny]

I've just purchased a couple of stihl 034's and an 024

 

Was advised that the 034's need pistons and cylinders.... but have not had the cylinders off just yet to check if i can get away with just pistons for them.

 

One of the 034's has the older style fuel caps, zamma carb and side adjust chain tensioner

 

the other o34 has a carb of which i cannot remember the name at the moment this has the fuel caps fitted, the style just before they went to the tool less ones, but has a front adjust chain tensioner.... wierd.

 

Was advised the 024 had possibly an air leak... it wouldn't start but after a clean through etc and fresh fuel it has started, and runs ok on manufacturors carb settings. One thing to note is that when the saw is turned upside down etc it will stall so would this suggest an air leak??

 

where can i find a kit to check for leaks? vac and pressure test and how much would i be looking at??

 

Cheers, i'm happy with my projects

[spudulike]

I've just purchased a couple of stihl 034's and an 024

 

Was advised that the 034's need pistons and cylinders.... but have not had the cylinders off just yet to check if i can get away with just pistons for them.

 

One of the 034's has the older style fuel caps, zamma carb and side adjust chain tensioner

 

the other o34 has a carb of which i cannot remember the name at the moment this has the fuel caps fitted, the style just before they went to the tool less ones, but has a front adjust chain tensioner.... wierd.

 

Was advised the 024 had possibly an air leak... it wouldn't start but after a clean through etc and fresh fuel it has started, and runs ok on manufacturors carb settings. One thing to note is that when the saw is turned upside down etc it will stall so would this suggest an air leak??

 

where can i find a kit to check for leaks? vac and pressure test and how much would i be looking at??

 

Cheers, i'm happy with my projects

 

Typically an air leak will manifest itself in a few ways - uneven idle, racing idle, not being able to reach normal idle speed without having a very rich idle mixture, poor midrange pickup and bogging, very fast top end revvs.

 

Your problem sounds more like the fuel blocking the breather causing the saw to stall - do you often use your saw upside down:confused1:

 

To pressure and vacuum check, you can go one of two routes, purchase the kit from Stihl or design your own kit that does the job at a fraction of the price - it depends how resourceful you are.

 

When faced with £200 on tools, I am very resourceful:thumbup:

[spudulike]

Just tached the 394 - gotta say that that saw sounds awsome on idle - just like the Allspeeds on RD350s in the day - lots or ring ting ting - nice and metalic....lovely:thumbup:

 

Anyway - it is good to go, revs out nicely 3/4 tankful through it - fab.

 

The MS390 I am doing for windfall is done - that is good as well, tached it and no adjustment needed, 1/2 tank through it and all is good, no damage to the engine when the decomp fell apart mid cut, a bit of damage to the top of the combustion chamber but a new piston & a small end bearing meant that the saw will cut again:thumbup:

 

All good from here - getting the kit to do vacuum testing now so will be able to pressure test AND vacuum test soon:thumbup:

[geoff]

Spud,I love that sound....the best for my ear is an old cr500 ring tinging & branging when you blip the throttle on any sunday morning!

[windfall]

Reminds me, look for "on any sunday" on you tube, its narrated by steve mcqueen. Proper 70s bikes and hair cuts.

[swinny]

Typically an air leak will manifest itself in a few ways - uneven idle, racing idle, not being able to reach normal idle speed without having a very rich idle mixture, poor midrange pickup and bogging, very fast top end revvs.

 

Your problem sounds more like the fuel blocking the breather causing the saw to stall - do you often use your saw upside down:confused1:

 

To pressure and vacuum check, you can go one of two routes, purchase the kit from Stihl or design your own kit that does the job at a fraction of the price - it depends how resourceful you are.

 

When faced with £200 on tools, I am very resourceful:thumbup:

 

The upside down bit was just an example, as doesn't it show that there is an air leak when the saw is held at different angles/sides?? etc, sure i've seen it somewhere?? maybe not...

 

but anyway, tried it today and there must be an air leak or something with the 024 so will have to investigate further in the next week or two when i get time