Plug check after light mods, help!

[OorWullie]

Hello everyone, I'm new to the forum but I have been using saws, strimmers and other 2 stroke tools for nearly 20 years. I aquired a husky 357xp recently which had been seized. I cleaned up the barrel with emery paper, fitted a new piston and ring, then found this site!

As I was putting it back together I decided to use a thinner base gasket, 0.020 instead of the standard one which I measured at 0.040. I replaced the air and fuel filters, pressure and vacuum tested it, and also made a dual port muffler. I mixed the fuel and oil at 25-1 instead of 50-1 for the first fill to help keep everything smooth while it beds in.

Factory carb setting is 1 turn out on high and low jets, so I went to 1.25 turns on each to richen it to compensate for the freer flowing exhaust. The saw runs great, but the plug colour is a bit pale, more grey than the biscuit colour I'd like to see. Should I be concerned? How much of an issue is it? And is an extra quarter turn on the jets rich enough for running in after the muffler mod?

I will retune after running a few tanks through it, but wanted to let everything bed in first .

Thanks for any responses!

 

[ericm979]

Keep in mind that 25:1 is leaner fuel:air mixture than 50:1. It's not a huge difference- 4% oil vs 2%- but it is a difference. It's big enough that you'll want to retune.

It's impossible to say how much you need to change the tune after your changes. It's specific to the individual saw and your exact mods.

Plug reading is kind of a dark art. I used to do it on race two stroke motorcycles. Color can be affected by the oil and fuel you're using. Saws are traditionally tuned to four stroke in the cut. That's easier to do and seems to work well. It's richer than I'd tune a motorcycle but that's ok.

 

[OorWullie]

Thanks for your answer. I have been using saws for a long time but hadn't ever considered mods until I found this site.

The 25-1 is fuel to oil ratio, not fuel-air.

I actually used the saw briefly this evening, made about 15 cuts in a 16" log and rechecked the plug, it was close to what I'd expect in colour after being under load as opposed to just fired up and run out of wood. A nice biscuity tan. I will fill my firewood pile this weekend and check again!

 

[ericm979]

The 25-1 is fuel to oil ratio, not fuel-air.

Of course. But oil is not fuel.

 

[Huskitoter]

How do like the 357?

It is one of the models I have considered if I buy a second saw. Any comparisons to a good 50cc saw?

 

[redunshee]

Hello everyone, I'm new to the forum but I have been using saws, strimmers and other 2 stroke tools for nearly 20 years. I aquired a husky 357xp recently which had been seized. I cleaned up the barrel with emery paper, fitted a new piston and ring, then found this site!

As I was putting it back together I decided to use a thinner base gasket, 0.020 instead of the standard one which I measured at 0.040. I replaced the air and fuel filters, pressure and vacuum tested it, and also made a dual port muffler. I mixed the fuel and oil at 25-1 instead of 50-1 for the first fill to help keep everything smooth while it beds in.

Factory carb setting is 1 turn out on high and low jets, so I went to 1.25 turns on each to richen it to compensate for the freer flowing exhaust. The saw runs great, but the plug colour is a bit pale, more grey than the biscuit colour I'd like to see. Should I be concerned? How much of an issue is it? And is an extra quarter turn on the jets rich enough for running in after the muffler mod?

I will retune after running a few tanks through it, but wanted to let everything bed in first .

Thanks for any responses!

Not sure what color"biscuit" looks like, but light brown is good. I don't believe its necessary to run a 25/1 mix. I use 40/1 whether I'm breaking in a saw or not. There is no fast and steady rule for carb setup. 1 turn will get it started , you then adjust from there. In your situation I'd set the hi needle so it burbles or "4 strokes at wot. This should go away when you cut with the saw. Whether that's 1.25 or 1.5 depends on the saw. I don't fool much with the Lo needle. I set it so the saw revs up smoothly without any hesitation.

 

[OorWullie]

I really like the 357. Loads of power for its size, happy to take up to 20" bar but most of the time I run 15". A colleague once told me it was too small and I'd be better with 368 or 372. We swapped saws for a fill (clearing a wind blow site for the harvester to come in and process, mixed sitka and larch, 15-18" diameter) and he ended up buying a 357 for his next saw! Only issue I have is the auto decompression, if you buy one I'd recommend going for manual decompression, the hose to the auto valve perishes too quickly next to the cylinder.

By comparison, it's mostly Stihl 261 we use at work now and the husky feels much more powerful and responsive. If you have a bigger saw and just wanted something small and light for firewood or aerial work I think the 346 is a great saw too, a little lighter than the 357, a little less power but still plenty with a 15" bar and a good sharp chain.

Thanks for the input on carb tuning. I'll take it out over the weekend and do a lot more cutting and see how it goes. I'm happy with how it runs, just thought the plug looked a little pale and having just replaced the piston I don't want to have to do piston and cylinder in a weeks time! Eric, I think I misunderstood, hadn't really thought of oil replacing the air in the mix. I definitely will keep a close eye (or ear!) on it as I move back to 50-1 and retune if needed. Thanks for the advice.

 

[Little Al]

With the mods you have described I would re hash the Fuel brew to 32/1 25 is a bit much mores so if you are using Synth oil I would not worry about the plug colour, tune your saw to "burble" at WOT cleaning up to 2 stoking in the cut. Doing a plug chop in a saw is a bit "iffy"reading wise as the there is away"s some run on unlike a bike when you pull the clutch the motor stops revolving any worries run a tiny bit rich

 

[OorWullie]

It does run nice, idles without stalling, no chain creep, picks up nicely as soon as the throttle is opened, little rough on WOT without load but cleans up in the cut. It was just the plug being a little pale that concerned me but general opinion here seems to be not to worry about that. Thanks.