So bought a chinese saw (holz g070)

[Breckinridge Elkins]

Appreciate it. Think I've got the sprocket sorted... Got spendy and ordered a rimdrive replacement. Now I'm hoping to get the gearbox cleaned up, with fresh oil and see what else needs fixed before I have a runner.

I started about where you are at. I was just going to flush and fill the gearbox, then swap the 1/2" chain for 404. Well, I just pulled the piston and con rod, now I am broken down to the nuts and bolts. So this has gone way further than I had planned.
I think I will be glad I did. If I had filled the gearbox it all would have leaked out. The entire outside of the saw was covered in fine sawdust glued by gear oil. The head and base gaskets weren't sealing anything. So in my case, the saw was never going to run. Looks like your saw is only a little younger than mine. Something to consider.
For me, there is a lot of sentimental value to this saw. At first I was just going to clean it up and display it. Now I am looking forward to seeing this old gear drive run.

 

[sliceoflife]

Does head gasket = carb/cylinder gasket?

 

[Breckinridge Elkins]

Does head gasket = carb/cylinder gasket?

Maybe I have my nomenclature wrong. I am referring to the gasket that joins the top of the cylinder (where the spark plug threads in) to the cylinder jug. This gasket is an aluminum plate. Then there is a gasket at the crank end. Both of these had totally failed. The crank seals look good but I did not test for compression/vacuum before starting this project.

edit: The carb is an entirely different can of worms that I have not addressed yet.

 

[sliceoflife]

Thanks, I'm trying to figure out what the second gasket you're referring to is.

#10 in this diagram I've seen people refer to as "Cylinder gasket", "Base Gasket" and "Head Gasket". (This parts sheet calls it cylinder gasket).

So when you say Base gasket and head gasket, you're saying I should check this gasket and which other one?

 

[heimannm]

The McCulloch 1-61 has a removeable head so it does, in fact, have a head gasket. There is no base gasket as the cylinder and crankcase are essentially one piece with a removeable side (crankcase cover) that has a gasket to seal it to the crankcase itself. Very different construction than any modern saw but a design that McCulloch used for 30 years or so.

In your illustration above, #10 is a base gasket and #31 is what I would call a crankcase cover gasket but I'm not familiar with Homelite nomenclature.

Mark

 

[sliceoflife]

Ah thanks. I misunderstood and thought Breckenridge was saying he had this same model saw and wanted to confirm what two gaskets he had trouble with.


So I removed cleaned and replaced gear cover... one screw was missing. Replaced that. Gasket there seems in decent shape. Filled it and letting it sit to see if there's a leak now


Gave it a few pulls and no spark, pulled the plug and pretty obvious why... not even worth trying to clean the contacts. New plug is needed. I'll be picking one up today and we'll see if it has spark.

 

[sliceoflife]

New plug. Got it to fire and run through the gas in the carb a couple times but it was a fight... thinking the carb is going to be a nightmare. Gonna swap the carb from my 775d on and see how she works then, then if she runs... decide if I want to rebuild ($10 kit) or replace ($40 carb).

 

[sliceoflife]

So carb is full of oil...



Probably crankcase sealing gasket bad? (Part 18 in that image above) and that's letting gear oil into crackcase where it's dripping/pushing back into the carb?

Is it possible it got filled with oil just to protect it when it got put away (No way I'm that lucky right?)


I do see a splash of gas in the bottom of the crankcase... doesn't look particularly oily... but kind of hard to tell. Definitely more gas than oil... so just amateur sleuthing, I'd think that if the carb oil were from blowback... wouldn't the stuff remaining in the crankcase be at least as viscous?

 

[heimannm]

Most likely the fuel evaporated leaving the oil behind. I had one this week that looked very similar.



Mark

 

[sliceoflife]

Thanks... carb gaskets look good to my eyes. One reed only had the slightest gap. I may just clean it and skip the rebuild kit unless I find something else when I am cleaning it....


Pretty sure a barrier of oil in the carb explains how it was acting.

 

[sliceoflife]

Cleaned the oil out of the carb, reinstalled. Tomorrow just have to screw the handle back on and I can test it.

If it doesn't run then....

On/off switch wire is disconnected... I plug it back on but it shakes off.... I would assume when its disconnected the saw defaults to run, but dont know for sure... so may be worth fixing that... and otherwise, next step would be a new carb or rebuild and then checking all the seals/pressure and vacuum tests.

 

[sliceoflife]

So it idles... and revs... but when I flutter the throttle, then let off... it revs down slowly in idle and stalls (see video).


Any idea what could cause this?


Old threads on same problem say too rich high tune... does this sound like that?

Haven't tuned high yet as I haven't put b&c back on yet.

 

[sliceoflife]

So high was tricky to tune.... with bar and chain on... there's only maybe 1/8 of a turn grace between the governor killing the saw and the saw flooding and sputtering out on idle after letting off the throttle... And even in that one bit of tune I have to open and close the throttle nice and slow.

If I punch it... governor snuffs out the saw. If I let off the throttle with a snap it floods and chokes out.

Possibly still some clogging in the carb that I didn't get? Or just old saw finicky-ness?


But with the saw in that tune... it'll idle... I can ease in the throttle and it'll run at wot... and I can ease off the throttle and it'll go back to idling.

 

[sliceoflife]

So my suspicion was that I probably shouldn't have skipped the rebuild kit... particularly replacing needle seat... described the problem to my father who ran these old saws years ago and first thing he said was check the needle seat... reinforcing my concern. .. so I'm guessing a new carb or rebuild is in the saws future... but for the moment it is running.


Ordered a cheapo rebuild kit to try... Like I said I think most of the parts are still reusable... probably just need to clean em better... but I want to have the parts available just in case if I find something I can't before I tear this thing apart again.

 

[sliceoflife]

So generic update...

It's in the high 90s heat index and sunny today; but I wanted to get the Holz G070 going, because it's sat a month. Did one slab with the new clutch + 8 tooth rimdrive sprocket and ran just fine before the fact that I was soaked through with sweat drove me back inside. Idle RPM still drops by 20-30% when the saw is hot; but I can tune the idle throttle up now without the chain spinning so it won't stall because of that anymore (Instead of 1350 idle cold and 850 idle hot (stalls), I can now run 1900 idle cold and 1200 idle hot (doesn't stall))

Next time out I need to run my Echo cs900, it's also sat over a month.

Carb kit and rim drive sprocket arrived for the 775G. Need to install the sprocket and move the bar and chain over from my 775D.

May just swap in the carb from the 775D while I'm at it; then I can rebuild the carb off the 775G at my leisure. I have a feeling the 775D is gonna wind up being a parts saw for the 775G anyway when it's all said and done... as I doubt I'll feel the need to run both of them. Will probably dump the fuel and disassemble the carb on the 775D now so I have one less saw I need to worry about sitting and gumming up. Need to do some research on best ways to winterize and/or store saws for longer periods.

And of course still need to rebuild the Super XL carb when I have time.

 

[J D]

That idle variation between cols & hot might be an indication it's too rich on the L.
Canned fuel or non-e fuel with a good stabiliser is probably your best bet for winterising. Can also just run the saw dry but some diaphragms will stiffen up if left dry for a long time. If the period of non use is extended fogging the motor can be a good idea too.

 

[Lil'Skeet]

ya would all depend on where it was on the muffler/cylinder idk anything about how the 070 bolts up. I did use my temp gun once on my poulan wild thing muffler tho and it was around 600 degrees F which is way to high for loctite.

I have used hight temp (red) loctite on some rowdy v twin choppers that like to puke bolts and nuts. Works well, use it sparingly if you want to remove fastener in your lifetime. Use a toothpick and put the smallest amount possible on the fastener.

 

[Lil'Skeet]

That idle variation between cols & hot might be an indication it's too rich on the L.
Canned fuel or non-e fuel with a good stabiliser is probably your best bet for winterising. Can also just run the saw dry but some diaphragms will stiffen up if left dry for a long time. If the period of non use is extended fogging the motor can be a good idea too.

Fogging works good. Filling (with straight 2 stroke oil) carburetor and an oz or 2 in the top end via spark plug hole works for years if not decades of storage.
I drain tank, add 2 ozs (2 stroke oil) in fuel tank, start saw keeping revs up. It will shut down quickly once premix is run out of carb and fuel line. At that point fuel line, carb and top end have lots of oil in them. Remove air filter, open butterfly add more oil, then oil down top end.
When ready to use again flush with fresh premix and start. Will be smokey when you go to start it again, be ready with a new spark plug.
Yeah, yeah, I know I'm adding a pound of carbon to the top end, whatever. Saves all fuel lines, o rings, top end and bottom end from rotting and rusting.

 

[sliceoflife]

Thanks guys.


Thanks for the idea on the Rich L, but I checked today and it's definitely not the cause of the variability on the idle... Problem stays even with the L needle almost fully seated. Definitely could be another problem with my tuning... I'm sure I still suck at it; but not that exact problem.


Disassembled the Super XL carb and cleaned it. It will need new gaskets though (kit en route). They had fused with the carb in spots and didn't come away cleanly.

Started pulling the 775D apart. I'm thinking I'll take some of the smaller bits (bar nuts, etc) as well as the carb off it to keep as parts for the 775g; and then sell the nonmatching/not needed parts or just sell the whole remainder of the saw as a parts saw:

It's got a .404 sprocket clutch in good shape... so I suspect based on how pricy those were for the 775G; that might be worth a bit... and the gas tank/handlebar/engine (scarred but it runs) might be worth it for some eBayer. Just have to go over it with a fine tooth comb and make sure there's nothing on it that I'm going to be needing for the 775G down the line and kicking myself for selling. Of course maybe I'll just stick it on a shelf until I feel the need to get it running again and I rebuild the spare carb and put it back together.

Still planning to stick the carb off it right into the 775G and probably put the sprocket I bought on it in the same go.


Did get my echo cs900 out for a very very brief run (the last 20% of a cut through a 20" log after the Super XL stalled out on me and didn't want to start back up and keep running... but of course it was the bottom of a massive log stuck down in the dirt; so now I've got a lot of chain sharpening to do on it before I use it again.

Getting into the rhythm of milling with the 070... simple ~20"ish wide slabs are taking about 10-15 seconds a foot; so making good progress when we get a day that's cool enough to actually get out there.

 

[sean donato]

Did you ever get a winch set up for your mill? If you haven't, you need to. You'll never go pack to pushing by hand.