My TS400 concrete saw rebuild

[alexcagle]

Cool.
They redesigned those because they were notorious to leak fuel out.
Which when cutting steel, sparks that are shooting at a gas tank leak is "no bueno".

In my experience, a fire is usually the result of someone not screwing the gas cap back on, or the o- ring on it is missing.
It's funny.
People think the saw is going to explode like in the movies.
All you gotta do is kick some dirt on it.
Now I did have a customer come in looking for a used top yesterday. We had some steady 40+ mph/ 65 + kmh wind last weekend here in the middle US, and needless to say, grass fires in high wind are bad news.
It burnt his garage, and his TS400 was in there. Freddy Kruger special.

 

[MattG]

Freddies back!!!!!!!!!!!!!!

 

[MattG]

That's definitely a very upset looking saw top

 

[MattG]

Hey @alexcagle

Any recommendations for the H-screw setting on my TS? I think mines just on 1 turn out right now. The muffler restriction is obviously minimal since I removed the inside tab thing and the UK STIHL stuff (this includes all my old skool chainsaws) never seem to have spark arrestors fitted.

It's obviously not a case of the chainsaw way of "rich enough to 4-cycle on WOT until it gets a load" since there's a rev limiter which, correct me if I'm wrong, cuts the show at round about 9.6K. What do you do? Do you just use a certain preset opening or do you have some kinda technique for these beasties?

 

[alexcagle]

Hold it wide open while running. Then while its still rinning, open the "H" screw up until it starts reducing the rpm and smoking alot from being overly rich, then turn it in slowly until it returns to normal. Then turn it in an 1/8th of a turn. Done.
Then run it in and back out to see where it ended up.

 

[MattG]

Hold it wide open while running. Then while its still rinning, open the "H" screw up until it starts reducing the rpm and smoking alot from being overly rich, then turn it in slowly until it returns to normal. Then turn it in an 1/8th of a turn. Done.
Then run it in and back out to see where it ended up.

Thanks, but what exactly do you mean by this:

Then run it in and back out to see where it ended up.

Because to prior that statement, i.e. Then turn it in an 1/8th of a turn. you'd kinda implied that it was done by then. The bit that you wrote (that I've put in bold italics) kinda says you can do more with the H-screw, i.e. "run it in and back out", so I kinda wondered. But the first bit you'd said (i.e. up to the word "Done") seems crystal clear to me.

 

[alexcagle]

That is just so you'll know where it should be set at in the future, plus I was curious as to what it ends up being set at too.
That peticular carburetor was the earliest, and only carburetor put on a TS400 that didn't have a "fixed jet", or non adjustable high side.

 

[MattG]

That is just so you'll know where it should be set at in the future, plus I was curious as to what it ends up being set at too.
That peticular carburetor was the earliest, and only carburetor put on a TS400 that didn't have a "fixed jet", or non adjustable high side.

Cool, Thanks Alex,

I see what you meant now.....and I'll sure let you know what setting it ends up at. Not for a while (couple weeks) though, got other stuff to do....but I'll probably throw the cutting end back together later this weekend...so who knows?

later Matt

PS I guess that makes my carb - a nice carb then?

 

[MattG]

Luckily I have quite an understanding wife, who's not too put out if I bring the saw into the study for the final reassembly, because I don't want my poor little feet to get cold in the garage....

Best hope I don't have a fuel leak, and luckily none of us smoke

 

[MattG]

Hi Alex,

Yet another ask.....thanks again for your patience....so I've got it almost back together....and since it's been a while ago that I took the bearing pulley off the belt. So am I right in thinking that to get it all back and tensioned that all I have to do is nail down the bearing cover screws, and then rotate the plastic hex head clockwise until I hit hard resistance and the arrow lines up (or thereabouts). Cripes it's so simple!!! Please confirm that's all it takes (manual just says the usual "reassembly is the reverse of disassembly"...yeah well thanks for stating the obvious!).

I mean when it went back ok, I just kept it all steady and made sure that the belt was kinda still in place.....and it all seemed like child's play.

 

[MattG]

Ok I own up.....I'm an english idiot you obviously need the bearing cover screws kinda loose first.... before you can tension it up. Yes the first try resulted in a stationary wheel.

Once my english brain woke up and I had it figured, I was down the back garden, where I found an innocent looking piece of concrete, and used Alex's H screw idea. I think it's now sat at 1 + 3/4 turns out.....though I probably only turned it 1/16 back in.....didn't want to overdo it. And atmospheric pressure wise I'm just about 5m above sea level.

Saw ran nice in the concrete....in fact especially nice after I refuelled it

later Matt

 

[MattG]

Hey Alex,

Another question. I got the TS400 setup with the H-screw set as above, and the L and idle set up so it's somewhere around 2700 (my tach is really jumpy at idle, it is on all my other saws) and the saw responds to throttle w minimal bogging and restarts well. However if you blip the revs when you release the throttle they drop to a little below the regular idle RPM and take about 1 second to "catch up". Is that pretty normal? (Perhaps all saws/engines do it to an extent....but maybe heavier clutch/flywheel exaggerate the feature.) I'm not unduly concerned cos it seems to work very well in other areas....massive improvement than before the rebuild....But I just wondered if you had an opinion/view on this?

Matt

 

[alexcagle]

That usually means it's slightly rich on the idle mixture.
You can turn the needle in, or clockwise, at 1/32nd increments to tune it out.
If there starts to be a hesitation, you may want to return it where it was.

 

[MattG]

That usually means it's slightly rich on the idle mixture.
You can turn the needle in, or clockwise, at 1/32nd increments to tune it out.
If there starts to be a hesitation, you may want to return it where it was.

Ok, thanks dude, will try that when I'm next cutting with it. Think I'm done with that one for now....certainly fixed the things I wanted sorting out...and I've got the confidence and experience now to dive in deeper on that saw in the future, if needs be.

Thanks again to all for the help and time.

Matt

 

[alexcagle]

You bet!
You're welcome.

 

[PhilKawasakiuser]

Different user with little experience using decomp ports. Mine read 75-80lbs slightly warn but decomp leaks. Exhaust side has some scores but not that bad. Carb choke floats round wiggling much. Couple that port be my biggest issue not its one. Another is if the port leaking caused a thing

 

[MattG]

Different user with little experience using decomp ports. Mine read 75-80lbs slightly warn but decomp leaks. Exhaust side has some scores but not that bad. Carb choke floats round wiggling much. Couple that port be my biggest issue not its one. Another is if the port leaking caused a thing

Test it comp again, but get a plug for the decomp first.

 

[PhilKawasakiuser]

I got around to messing with it again and noticed that the flywheel side of the crankshaft has up and down play in one spot. I don't know how to take the belt off properly so I haven't tested that on the other side. I just got a plug for the decomp but haven't done that yet. The piston has some real damage on the exhaust side tho. I would kinda like to eventually rebuild it but don't know how to get its flywheel off without the rubber or lead mallet and torque lock pliers. My puller is only for a few echo, husq and poulan chainsaws under 50cc's.

 

[PhilKawasakiuser]

I got around to messing with it again and noticed that the flywheel side of the crankshaft has up and down play in one spot. I don't know how to take the belt off properly so I haven't tested that on the other side. I just got a plug for the decomp but haven't done that yet. The piston has some real damage on the exhaust side tho. I would love to eventually get it back in action don't know how to get its flywheel off without the rubber or lead mallet and torque lock pliers. My puller is no use here. Don't even know how to remove the belt. I have no experience really working on cutoff saws. Its got the 3bolt coil and h an l adjusting needles on the original carb which I think is practically like that ts400 top from the garage fire. Already have a replacement carb and alot of parts to rebuild it. I had planned on getting it done but lack the required knowledge to do so.

 

[MattG]

I got around to messing with it again and noticed that the flywheel side of the crankshaft has up and down play in one spot. I don't know how to take the belt off properly so I haven't tested that on the other side. I just got a plug for the decomp but haven't done that yet. The piston has some real damage on the exhaust side tho. I would kinda like to eventually rebuild it but don't know how to get its flywheel off without the rubber or lead mallet and torque lock pliers. My puller is only for a few echo, husq and poulan chainsaws under 50cc's.

Dude, that sounds like the bearings and hence the seal on that (f/w) side is shot.

You do need to get that wheel off. (i.e. rebuild it and don't let that beauty of a machine die!).

If it's like a chainsaw f/wheel try to remove it without the proper puller. Here's how I do it, I usually rope in my wife/a friend/relative to help hold stuff.

1. take out spark plug, eye the piston, and move piston so its 1/2 inch from TDC
2. jam loads of thin clean rope or a boot lace like me, into the combustion chamber, this will lock the crank when you turn in counter clock wise to get the nut off the crank
3. thread the nut back onto the crank for protection, but leave a gap of say 1-2 mm behind the nut and the wheel
4. get wife / friend to pry from under neath the wheel, if ness use a strip of wood tween the bar and the engine to protect it,
5. you get nice stout drift, old bolt, etc. and place on tip of the crank shaft
6. give it the drift a few quick sharp wacks

You might need a reasonable amout of force with above approach. But it's probably a bit easier, and safer than the puller method (which could tear the threads on the wheel/puller)

Hope this helps you out buddy, or ask @alexcagle to see what he reckons