So bought a chinese saw (holz g070)

[Ted Jenkins]

Holeycow. You mean literal first 15 seconds? That's Idling. I rev the saw twice but other than that it's just idling until 0:41 in video... If I lean the L up any, RPM climbs and the chain starts to spin. If RPM goes over 1500, chain spins... Saw is supposed to idle @ 2500... but it could practically mill @ 2500 the chain is so active. I assume clutch/springs are low quality is the problem. Any fix for this other than replacing the clutch/springs?

I have several 070s and they do not have the problem you describe. I also have several clutches from several sources which leads me to believe that your tune is off. I think about 1500 RPM is about right. I have never heard of 2500 RPM. Have you tuned and adjusted idle. I would start with the idle turned in until engine will not idle at all then adjust until engine barely idles. Adjusting L screw until engine idles fast is common because the mixture is lean. So adjust L until you get good throttle response then adjust until chain does not spin. I think your goal would be less than 2,000 RPM. Hope that directs you to the proper setting. Thanks

 

[holeycow]

Holeycow. You mean literal first 15 seconds? That's Idling. I rev the saw twice but other than that it's just idling until 0:41 in video... If I lean the L up any, RPM climbs and the chain starts to spin. If RPM goes over 1500, chain spins... Saw is supposed to idle @ 2500... but it could practically mill @ 2500 the chain is so active. I assume clutch/springs are low quality is the problem. Any fix for this other than replacing the clutch/springs?

No, after you start cutting. Your tune is off. Nothing to do with the clutch. Yet.

 

[holeycow]

Do what Ted says first. Set the idle. Then adjust the low. Then adjust the high. In steps. Slowly with everything.

It made me laugh when you said about the first bit at idle. Not laughing at you, but it made me smile. The difference between idling and cutting could not be mistaken...not likely.

I think Ted might be onto something there with your idle.. start there.

 

[sliceoflife]

So not 2500, my mistake... 2000 according to stihl, 2800 according to holzfforma... either way, if you say 1500 is closer to accurate, that's good... because the play I have rpmwise between stalling @ idle and the chain running is ballpark 1300-1480.

Really dont have much leeway on idle screw. Less than 3/4 turns in it dies. More than 1 turn in, chain spins... likewise the L screw needs to sit almost exactly at 1 turn out. I've got maybe 1/8 turn either way to play with, but it definitely doesn't idle better in those ranges.


Holeycow. Yeah I felt stupid having to ask, but I tend to read things quite literally and I wasn't sure if maybe you were trying to make the point that the idling sound was concerning.

 

[Ted Jenkins]

So not 2500, my mistake... 2000 according to stihl, 2800 according to holzfforma... either way, if you say 1500 is closer to accurate, that's good... because the play I have rpmwise between stalling @ idle and the chain running is ballpark 1300-1480.

Really dont have much leeway on idle screw. Less than 3/4 turns in it dies. More than 1 turn in, chain spins... likewise the L screw needs to sit almost exactly at 1 turn out. I've got maybe 1/8 turn either way to play with, but it definitely doesn't idle better in those ranges.


Holeycow. Yeah I felt stupid having to ask, but I tend to read things quite literally and I wasn't sure if maybe you were trying to make the point that the idling sound was concerning.

I have been tuning two strokes for over sixty years so to me adjusting is automatic but those that have never heard what to listen for are stumped. Even though I have several big bore saws I forget what I am listening for because of the governors. When You have some doubt as to what is going on pull your plug. You can not fool your plug. Or almost as reliable is do not pay any attention to how your engine is running but make sure your adjustment screws are slightly out more than needed. Start your saw and start cutting. When you do this your engine should quite quickly smooth out and run clean. If it bogs or races a bit you have found the problem. What I do is guess at the adjustments then let it idle for a moment. I pull on the throttle and listen for good throttle response. If it responds well I move to the idle and H screw but not until it feels like I have instant power. Thanks

 

[Maintenance supervisor]

I put an Oregon rim drum on mine and a new clutch, it still wants to spin a little bit at a reasonable idle setting, I wouldn't focus on that as much. The cheap Chinese clutches are pretty loose on their specks.

 

[sliceoflife]

Yeah, I'm having to keep it in the low 1400's to keep it from spinning at idle... Whatever... It starts there so no worries.

Got it milling well and was on par to finish a 7ft slab in under 3 minutes (~18" diameter log I'd guess)... but last foot or so it started struggling. Got it out of the slab and let off the throttle and it immediately died. chain was sagging out of the bottom dead center of bar and took some force to get back in. Assumed I ran out of bar oil and that section was gunked up with dust... but nope... turns out the bar got pinched there. Chain needed tightening anyway (which requires removing the mill)... so I took it apart, wedged out the pinched section of bar with a screwdriver, and put it back together. May try and take a few more slabs off later today if I have time.

Otherwise it's chugging along. Theres a few spots here and there where it starts four stroking again when milling, but if I feed it into the log a little more; it cleans up right away.

Built myself a cute lil 8x4' solar kiln last month; so I'm eager to get some more slabs done to fill it up (Only fits up to 7'3" long slabs... so the last log I did was too long to fit).


Nut shook loose from the muffler mount too... so that got replaced.

 

[sliceoflife]

Started to cut another slab this weekend and 6" into the log; the chain stopped. Pulled it out of the log and chain still wouldn't move.

Took it apart, took chain off and clutch spins. Reinstalled chain... it won't move. Rotates just fine by hand.

Did clutch just burn out or?

 

[OM617YOTA]

Can you move the chain by hand on the bar?

If not, check bar groove, check each drive link, etc. You have something wonky.

 

[sliceoflife]

Can you move the chain by hand on the bar?

If not, check bar groove, check each drive link, etc. You have something wonky.

Yes chain spins just fine by hand.

With bar and bar cover off; the cluch/sprocket assembly spins just like you'd expect when saw is running

With saw + bar + chain all put together... I can lay on the throttle and absolutely nothing moves.

 

[fields_mj]

Yes chain spins just fine by hand.

With bar and bar cover off; the cluch/sprocket assembly spins just like you'd expect when saw is running

With saw + bar + chain all put together... I can lay on the throttle and absolutely nothing moves.

I'm an amateur at chainsaw repair, so bare with me here.

Just to recap - Correct me if one of these is not true.

With the chain on the bar, but the bar off of the saw, the chain moves freely.
This would mean that the sprocket spins freely, the bar is not pinched, and none of the drive links are bound up or damaged.

With the bar and chain off the saw, but the rim/sprocket and e-clip installed, clutch cover removed, and the saw running, the drum and rim/sprocket spin when you hit the throttle.
This would mean that the clutch and break are working correctly when there's no load applied.
Question here: If the above statement is true, is the saw pumping bar oil out when you do this?

With the bar and chain on the saw, clutch cover removed, e-clip installed, and saw is not running, the chain spins freely by hand.
This indicates that nothing is bound up.

With the bar and chain on the saw, clutch cover installed, bar nuts are properly tightened, saw is not running, the chain won't move on the bar.
This would indicate that your clutch cover is somehow pinching either the chain, the rim/sprocket, or the clutch drum. There should be a wear mark on the clutch cover.
If the e-clip is seated in the groove on the drive shaft, then maybe the stud for the bar nut has worked loose? (has been known to happen on the clones).
If the e-clip is not seated in the groove, then you may have something wedged under the clutch drum. Maybe a broken spring on the clutch (known to happen with the clones). Use a 1/4" impact and a 19mm or 3/4" socket to remove the clutch. It's a left hand thread so run the impact forward to remove the clutch and see if anything is floating around in there. Check the springs on the clutch and the clips to see make sure everything is present and in good condition.
Check the arm from the oil pump and make sure the tip is in good condition while you have it apart. If it's worn already, get a replacement.
When reinstalling the clutch, make sure that the notch on the edge of the drum lines up with the arm from the oil pump. If it does not, you'll wear the afore mentioned tip out and have to replace the arm.

I can't think of any other failure points to investigate.

 

[sliceoflife]

Chain on bar bar ON saw, I can spin chain just like normal.
Saw running, give it throttle... nothing moves.


Chain and bar off saw, give saw throttle... sprocket and clutch cover spin.


Not being an expert... its acting like the clutch slips with any kind of resistance.

 

[fields_mj]

Chain on bar bar ON saw, I can spin chain just like normal.
Saw running, give it throttle... nothing moves.


Chain and bar off saw, give saw throttle... sprocket and clutch cover spin.


Not being an expert... its acting like the clutch slips with any kind of resistance.

Sorry. I accidently hit enter and posted my reply WAY too soon

I suspect that your clutch is shot. The one on my G660 went in the first tank of fuel but that was because the e-clip on the drive shaft didn't have any temper to it. It came off of the drive shaft and allowed the drive bearing to slide out from under the clutch.

Copying this from my previous post, here's how I take my clutch off. I've made a few corrections that were originally written in haste. Like I said, I'm an amateur.

Remove the e-clip. Slide of the drive sprocket/rim. Lift the drum straight out. Slide the drive bearing off of the drive shaft. See if anything looks wonky with the clutch.

Use a 1/4" impact and a 19mm or 3/4" socket to remove the clutch It's a left hand thread so run the impact forward to remove the clutch and see if anything on the back side looks out of place. Check the springs on the clutch and the clips to see make sure everything is present and in good condition.

Check the arm from the oil pump and make sure the tip is in good condition while you have it apart. If it's worn already, get a replacement.

When reinstalling the drum, make sure that the notch on the edge of the drum lines up with the arm from the oil pump. If it does not, you'll wear the afore mentioned tip out and have to replace the arm.

 

[sliceoflife]

So I pulled the clutch cover off and was trying to get the clutch out to take a look at it. Couldn't figure out how to get it out with that wedge piece in the center couldn't find any way to get a grip and pull. Found some videos suggesting my problem is usually caused by that piece breaking... so all the videos repairing it show it pulling right out... definitely not able to do that with mine... so I put everything back together and torqued the reverse threaded nut holding it all together way down. Started her up and she pulls the chain again... haven't tried any real load... but I'll report back as soon as I get a chance.


Where exactly is the e clip? I couldn't get the clutch assembly to budge, assumed it was that insert in the middle of it... but there's no way to grip it to remove that. Is this e clip what I need to remove instead?

 

[J D]

+1 for something behind the clutch drum.
If it only manifests itself once you properly tension the chain it could be a bearing issue (most likely clutch drum bearing).
Is it rim or spur drive?
Is the chain definitely on the rim/spur correctly?
I believe the 070/090 clutches have a sort of tapered clamp rather than spinning off (the retention nut is still reverse thread) & you usually need a puller to remove them.
Hopefully someone more familiar with this series will be along to enlighten us shortly

 

[fields_mj]

So I pulled the clutch cover off and was trying to get the clutch out to take a look at it. Couldn't figure out how to get it out with that wedge piece in the center couldn't find any way to get a grip and pull. Found some videos suggesting my problem is usually caused by that piece breaking... so all the videos repairing it show it pulling right out... definitely not able to do that with mine... so I put everything back together and torqued the reverse threaded nut holding it all together way down. Started her up and she pulls the chain again... haven't tried any real load... but I'll report back as soon as I get a chance.


Where exactly is the e clip? I couldn't get the clutch assembly to budge, assumed it was that insert in the middle of it... but there's no way to grip it to remove that. Is this e clip what I need to remove instead?

The e-clip is the little metal clip that holds the sprocket/rim on the end of the drive shaft.

 

[sliceoflife]

Would that hold the clutch in place once the cover was removed, or does it just keep the sprocket in place?

I wasn't even planning to remove the sprocket and rim I was just trying to extract the clutch assembly from within the drum and couldn't get it to budge.

 

[sliceoflife]

I believe the 070/090 clutches have a sort of tapered clamp rather than spinning off (the retention nut is still reverse thread) & you usually need a puller to remove them

Yeah that's exactly the problem I ran into. Clutch spun free once cover was off, but wasn't dethreading at all... and couldn't be lifted out either. seems there's a kind of wedge insert inside it that pressure clamps it in place.


Spur and yeah chain was on right.

 

[fields_mj]

I don't have an 070. Closest thing I have is an 064 and a G660. On all of mine, you take the clip off first. It (and the washer under it) holds the rim, drum, and drive bearing onto the drive shaft. When removed, all 3 of those will slide off. From there, I spin the clutch clockwise and it comes off exposing the oil pump assembly. Sounds like the 070 is a little different. I'll refund you my fee

 

[user 189819]

Two more uses.. Still trying to get the High adjust tuned in to where the saw doesn't sound like it's about to blow up whenever I punch it when milling... I'm about 3 turns out and I think I'm close but maybe still a little lean. I'm having to hold the trigger half in because I can't lock it at full throttle; it sounds too angry at full throttle and Im worried it'll blow up. Got a Tachometer ordered to try and get some peace of mind.


Also... So the Decomp valve stops working for 5-15 minutes with the saw hot (stopping it between slabs for instance). It works if the shutoff is turned off... Pulls like normal (but obviously doesn't start) but as soon as I turn the shutoff back to Run, the decomp no longer works and I damn near break my hand trying to pull the saw over because as soon as the cylinder tops out (half a revolution of the flywheel) it Snaps the pull cord back. Let it cool off for 5-15 minutes and it works again.

Too tight a fit in the cylinder when it's hot I'm guessing... and the shutoff/kill switch being turned to OFF somehow fixes that why? Anyone have any theories?

Careful there. I broke my finger pulling a handle on a messed-up gas pressure washer. No fun at all, but it's all fine now (after surgery and rehab).