Fixing a McCulloch MT725 (by MTD) 31cc String Trimmer - $20 Equipment Lot Ep.04

In the fourth episode of the $20 Equipment Lot, I pull this McCulloch MT725 (Item# 41AD725G977) 31cc Trimmer out of storage to fix with very little resistance.
The $20 Equipment Lot Playlist - • The $20 Equipment Lot
Zama C1Q-P22A Carb Kit: GND-18 or RB-52
fuel lines, carburetor cleaning, carburetor disassembly, carburetor assembly, Zama C1Q-P22A, metering diaphragm, primer bulb, purge bulb, fuel filter, clean gas tank
#smallengine #smallenginerepair #repair #troubleshooting #mcculloch #mtd #2stroke #stringtrimmer #weedeater #weedwacker

[@KPaul7]

Nice, I just picked up a blower of the same brand. The recoil is going to be fun...not. that could be another video. Good call on tuning it in warmer temperatures. It sounded like it was four stroking. What do you think and how do you adjust string trimmers? I adjust them with no four stroking. On chainsaws I know to adjust to four stroke on purpose.

[@BackyardRepairs]

I think everytime I’m tuning these in person I feel they’re 95% there, and then when I listen back during editing they’re always off lol. I think this one sounds like it ended up slightly 4-stroking, but in my experience this engine design sounds deeper than your typical 25cc which makes it a little harder to discern that, maybe that’s just me. But my normal process is to have line spooled out to put “normal” drag on the engine, then adjust the high to where the engine is at it’s fastest and then richen it up until just before it 4-strokes, but reliably 2-strokes. I’ll then move to adjust the low, and idle speed at a happy medium between not stalling and not engaging the clutch. Although sometimes I’ll start with low so it’ll stay running during tuning if the high is so off that it bogs out so the plan can go out the window on a case by case lol. I usually carry a screwdriver around during the first couple uses to fine tune on the fly after that tho.
What type of McCulloch blower did you grab? I did one a little bit ago, but it did not have any identification tags on it other than the branding which I thought was odd

[@KPaul7]

@BackyardRepairs lol and I do the same, adjust on the fly. I use all the equipment I fix. I'll have to look at the blower and get back to you