McCulloch Chain Saws

[Jethro 2t sniffer]

I've got a Super 250 that I like to use. I got tired of messing with the carb so I bought a Chinese version of the Stihl 090 carb for about 20 bucks. Best 20 bucks, I've spent. I did have to modify the linkage and add a bolt for the air cover. Runs like a new one, also using a Husky 55 coil on it.

I feel like 2broke did that to a mac a while back actually

 

[2broke2ride]

I feel like 2broke did that to a mac a while back actually

I did, had poor results. I might revisit it again at some point.

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[2broke2ride]

View attachment 885446
Mark

That's what I thought........ not sure what's going on. [emoji53] I wonder if the tit on the diaphragm is too big to fit down in the recess and push the lever.......

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[Jethro 2t sniffer]

I did, had poor results. I might revisit it again at some point.

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Ahh right. Hit n miss with old mate China lol

 

[edju1958]

That's a shame. Why say "Special Edition" if nothing is special about it ?

Justin

Justin,I have just a regular run-of-the-mill 10-10S & it has regular slotted screws that hold the recoil cover on.I know a guy who has a 10-10S Special Edition & the screws that hold his recoil on are Torx head screws.I guess that's what makes it a "Special Edition" other than the sticker.

 

[emf123]

So I went ahead with a Tillotson swap on the Super 250 until the parts for the flatback show up. I pulled an HL63D and the necessary adapter and linkages from a parts 1-52 I had here. I opened it up and it was remarkably clean inside but the metering lever was set way too high and I went ahead and put new diaphragms in it as a matter of coarse. Popoff pressure was right about 8psi after the rebuild with some slight bleed down but acceptable compared to the other Tillys I've done.
The thing will not draw fuel!!!! There is fuel in the line at the carb and it is getting fuel into the pump part but nothing in the metering chamber. How is the lever supposed to be set? It should be flush with the chamber floor correct? Or am I having a brain cramp and it should be level with the gasket surface?
Also, it does fire on prime andnwould start and run with the flatback, it had crap floating around in the carb making it erraric.

I would check to make sure you're impulse holes aren't being covered up by the gaskets or misaligned somehow.
Eric

 

[2broke2ride]

So I went ahead with a Tillotson swap on the Super 250 until the parts for the flatback show up. I pulled an HL63D and the necessary adapter and linkages from a parts 1-52 I had here. I opened it up and it was remarkably clean inside but the metering lever was set way too high and I went ahead and put new diaphragms in it as a matter of coarse. Popoff pressure was right about 8psi after the rebuild with some slight bleed down but acceptable compared to the other Tillys I've done.
The thing will not draw fuel!!!! There is fuel in the line at the carb and it is getting fuel into the pump part but nothing in the metering chamber. How is the lever supposed to be set? It should be flush with the chamber floor correct? Or am I having a brain cramp and it should be level with the gasket surface?
Also, it does fire on prime andnwould start and run with the flatback, it had crap floating around in the carb making it erraric.

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This saw is frustrating me. I rebuilt a second Tilly this afternoon, this one is an HL63E. It is pretty much acting the same although I did get this one to actually run, it is starving for fuel. It will only run on choke even with the needles 3 turns out. If I didn't know better I would think the saw has a massive air leak. Not sure where to go from here. I've never had a problem with the hi speed check on one of these carbs, also seems weird that 2 of these carbs are acting similar. It is worth noting, I am only changing gaskets and diaphragms because those are the kits I have on hand. I also ordered a complete RK88HL kit that will be here tomorrow.

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[2broke2ride]

I would check to make sure you're impulse holes aren't being covered up by the gaskets or misaligned somehow.
Eric

Checked, double checked, triple checked lol. Thanks for the suggestion though.

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[PogoInTheWoods]

I'm going with major air leak, myself. Not enough case pulse to move enough fuel -- along with way too much air everywhere else.

 

[2broke2ride]

I'm going with major air leak, myself. Not enough case pulse to move enough fuel -- along with way too much air everywhere else.

I haven't leak tested it, but it ran half decent with the flatback. I could cut with it but every now and then it would foul and I'd have to hit the choke a couple times and it would clear up and run fine for a while again.
I may have to get my block off plates out and leak test it though.

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[2broke2ride]

I also noticed while I had it running, there seemed to be a lot of air in the fuel line, all the lines are new.......check valve in the carb maybe? I have the Tillotson manual printed but they are not clear on where the check valve is located or how to check/replace it.

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[Turd Furgeson]

Hey Guys,

I bought a NOS Oregon roller nose bar from a small engine shop that was supposed to be a MAC pattern. I tried mounting it on my 125, 790, and 550. The tail doesn't clear the clutch and when holding the bar plates up to the bar the adjuster and oil holes don't line up. The seller insists it's a older Mac pattern, I know there were a few versions, but after looking at an old Oregon chart, I think this bar is a H010 mount for old Partners.

Can anyone confirm?

The model number on the bar is 33441

Thanks,

Scott

 

[briguy26]

hi fellas, was wanting to know if I have my lines hooked up to my carburetor correctly. Does that top nipple need a hose hooked up to it? Its a mcculloch double eagle 50 with a zama m10 carb. It will start with mix put in cylinder but immediately dies after that like its not getting gas. Any help would be greatly appreciated thanks.

 

[Maintenance supervisor]

Hey Guys,

I bought a NOS Oregon roller nose bar from a small engine shop that was supposed to be a MAC pattern. I tried mounting it on my 125, 790, and 550. The tail doesn't clear the clutch and when holding the bar plates up to the bar the adjuster and oil holes don't line up. The seller insists it's a older Mac pattern, I know there were a few versions, but after looking at an old Oregon chart, I think this bar is a H010 mount for old Partners.

Can anyone confirm?

The model number on the bar is 33441

Thanks,

Scott

Whats the part #?

 

[Turd Furgeson]

Whats the part #?

33441

 

[Maintenance supervisor]

yeah I don't think its a McCulloch, it could be the Stihl/Partner mount ? How wide is the slot 14mm?

 

[2broke2ride]

I also noticed while I had it running, there seemed to be a lot of air in the fuel line, all the lines are new.......check valve in the carb maybe? I have the Tillotson manual printed but they are not clear on where the check valve is located or how to check/replace it.

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So does anyone know if this HL63E has a check valve? And if so where it is located.
The Tillotson manual is clear as mud about it.

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[Turd Furgeson]

View attachment 885689yeah I don't think its a McCulloch, it could be the Stihl/Partner mount ? How wide is the slot 14mm?

9.5 mm or 3/8" , it's .058 gauge so that kind of rules out Stihl.

 

[emf123]

I haven't leak tested it, but it ran half decent with the flatback. I could cut with it but every now and then it would foul and I'd have to hit the choke a couple times and it would clear up and run fine for a while again.
I may have to get my block off plates out and leak test it though.

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You're sucking air. My next guess would be bad reed valve. They get warped or burned on the edges. I rebuilt a 660 with a Tilly carb, new reeds, new seals, and it will sit and purr like a kitten, idling away. And it revs up and fricking rips! Stick with it, you'll be rewarded.

 

[PogoInTheWoods]

So does anyone know if this HL63E has a check valve?

No check valve listed for either of those HL's. D18 'check valve nozzle' is listed in the misc. parts diagram section of my Tillotson HL material as part number 012084, but it's not pictured/identified in the main exploded parts diagram illustration. There appear to have been 2 or 3 checked nozzles used in HL's over time, mostly in sled and kart applications from what I can tell. Aftermarket versions of the nozzles are readily available from the kart and sled parts suppliers.

Quit pissin' up a rope. Do a leak check on that thing.