Ok you new saw tuning experts..

[weimedog]

My kid eBay'ed a brand new little 33cc Homelite with 16in bar for $65 bucks....his first saw as his dad(me) let him get one as long as it had all the safety stuff and was around 10lbs. (Do as I say not as I do!) He had $75 to spend......the Homei was $65 including shipping. Works for us.. (yea, I know its not a Husky,Stihl,Dolmer,Solo,Redmax, classy saw...but its his saw bought with his bucks and thats important to him.)(He's 100lbs soaking wet)

Starts easy and all that ..does what he wants.

It has a "bog" going from idle to full throttle. A lean fuel condition bog is what it feels like. It also has those little plastic limiter's on the carb adjustment screws.

Is it worth ripping off those limiter's and trying to richen the jetting? Or is this just what you get with a 33cc mini motor with a relatively large carb?

Once it's out of the "bog" it runs suprisingly well. It starts well and idles forever. Just that transition from no throttle to full. Mess with it or is that a fruitless pursuit?

 

[sedanman]

NONE of my personal saws have limiter caps. MOST of my equipment has fully adjustable carburetors. My most anemic saw an MS-170 now has a fully adjustable carburetor and does everything as well as any saw I own, starts easily, idles well, acelerates properly and 4-strokes slightly out of the wood. Take a good look at those limiter caps, it may be better to cut the tabs off than to remove the cap entirely. Newer Homelites have real small heads on the adjusment screws and the limiter cap, properly modified, makes adjusment easier. And as hard it is going to be to do, set a good example for your boy. You can't very well tell him to wear personal protective equipment and not do the same yourself.

 

[Porkchopper]

I picked around on my ms170 today and I realized it only has one adjustment on the carb. I opened up the muffler on it and you can really tell a difference. With no adjustments I hope it ain't runnin too lean. What options do I have?

 

[Crofter]

The one 170 I had my hands on seemed pretty lean as it was, and since opening the exhaust usually requires a richer HS mixture I would be very worried about using that saw. Likely someone here can give you info on resizing the jet or another swap on adjustable carb.

 

[sedanman]

The carb on my MS-170 came off an older 023. The olny problem is, it is not a direct swap. The 023 carb had an extra port for impulse that had to be blocked off. I took the carb apart and JB welded the port closed. When the epoxy hardened I put the carb back together and then had to drill a few holes in the handle of the saw to reach the adjusment screws. Muffler mods are next for the little bugger.

 

[weimedog]

The answer is a resounding "YES!"

I pulled off the top cover, the pull start, those goofy little guards around the tuning screws and then pulled off those plastic limiters with a pair of plyers(I'm a brass hammer mechainc). Put them in a vise and filed off the "lobes" that are the actual limiters. Stuck everything back together..

After tuning on my test wood I ended up adding about 1/2 turn to the high speed and aprox 1/4 to the low past where they were blocked...folks its a different saw. Amazing what a little fuel can do. It actually pulls harder in a cut and there is no bogging at all when that transition from no to full throttle happens. Can even (gasp..) put the saw ON the wood and then hit the throttle and it won't bog&tear right into a cut...LOL

Begs the question..WHY? won't running that lean wear the guts of these little screamers faster??

The two other issues I want to resolve with this saw is the hard trigger pull and it SOAKS the chain with oil. Looks like the return spring is a little strong.


Other than that its a nice little saw. And the price is right. From a design stand point its obviously engineered with a mission. The only structural part I don't like is the lighter than I would like cover over the clutch/sprocket. They molded in steel bushings where the studs go through so its a cosmetic dislike not really a practical one....after two gallons of fuel it runs much better. Also its beginning to display enough power to consider a better chain/bar configuration.

 

[stihltech]

170

BEFORE you worry about changing jets, do yourself a favor and make sure the inlet lever is flush with the top of the carburetor, with no gasket. This is the biggest thing I find. Also clean the carb up anf replace anything that looks bad. If it has any years on it, instal a carburetor kit. Then tune it up with a fuel filter and sparkplug.

Do the basics first, THEN we will worry about changing the jet size. I did a lot of jets up until a year ago, it has dropped off drastically since. The saws sound much better out of the box now.

 

[weimedog]

OK the start of this post was almost three years ago! And that little Homelite has had the crap run out of it by the wife and kids limbing trees and doing barn carpentry and surgury....Still run like it did out of the box (With the limiters removed from the carb mixture adjustment screws) Crisp clean easy starter. Bottom line? Been a good investment for 65 bucks...

I saw that video of a "muffler modded" homie....How hard is that to do? Drill a couple of holes?

For kicks...I think I might just ebay another and hack the cylinder a bit..any one do that with one of these?

 

[Bowtie]

I modded a little Poulan that is similar to that saw, and it made a hell of a difference. Almost any 2-stroke can benefit from a muffler mod, although I hear the catalytic converter saws should not be modded.

 

[Al Smith]

Well Walter it doesn't really take too much to pep up those little saws.If it were me I would just open the muffler up a tad bit and go from there.

A slight improvement of just 10 percent makes a lot of difference on a small saw,well really any saw,regardless of size.

Everybody has an opinion on saw mods,mine is rather conservative regarding working saws.I always figured that if you can get the thing to just"breathe" better and not fiddle too much trying to change the port configuration you are better off in the long run.Most little saws have plenty of rpm's and just a little more torque in the cut is what they really need ,which as a general rule can be easily obtained by a simple muffler modification.

 

[weimedog]

So whats the best way to open up the muffler? I saw a pic of a guy who poked three holes in his..what do you folks suggest?

 

[Al Smith]

Oh I've seen them add cute little pipes and megaphones and drill them full of holes,like Swiss cheese.I don't know if all that does anything other than make them look "cool",certainly louder,that's for sure.

Being some what crude at times,on a Stihl 038 I just opened the slot a tad bit with a screwdriver.It woudn't win first place at the rod and custom show but it did pep up the saw.

One thing you have remember,bigger is not always better.Not all or perhaps any will agree but my rule of thumb is around 60 to 80 percent of the exhaust port area for the muffler outlet.

Once,on another part of the internet I cautioned a fellow Ohioan about hogging out a muffler on an 088 Stihl too far.A few months later I saw the item listed on e-bay,scorched cylinder,ugh.

 

[weimedog]

Well I couldn't resist Al's approach....step one:

That muffler on a 33 cc Homei Ranger is more sophisticated than I thought it would be, so poking holes probably isn't a good idea.

BUT about a 15 minute mod DID yeald a definite change in mid range performance.....and about (by the ear) a 250-400 RPM increase. (after adding a little fuel via card mixture screws to the equation about 1/8 turn on Hi Speed and none on the low speed)

WHAT did I do?

1) Remove muffler (three nuts and the muffler & paper gasket are in your hands)

2) Use torx driver to remove "deflector" plate on the "chain" side of the muffler.

3) Remove screen...spark arrestor which is virtually useless anyway...

4) Use a 1/2 wrench as an anvile and use hammer and punch to drive that opening slot from a "pinched in" rectangular shape to a pushed out almost triangular shape and about 1 1/2 times the origional cross sectional area...

It still deflects the exhaust to the front as it should.

The saw is only a bit louder.

I had removed the adjustment limiters on the carb adjustment screws before anyway..and had to retune after doing this to the muffler over my starting point just a bit...

Cheap power increase...and INSTANT gratification for a clutch head:rockn: .

REMEMBER...play this game...things can roast.
Remember to retune the carb and my bet is Al's rule of thumb of the exit of the muffler should be in the 60-80 percent of the exaust port size is what I ended up with..closer to the 60percent.

IF I can find another one of these cheap..I will take this further...since this thing is a favored saw in the house hold...its not going to be hacked much.

There is a LOT of room in the muffler and muffler area on this little Homie to play with..other options may happen.

Also to my surprise the cylinder, piston, crank case are beefier than I would have expected for a cheapie...is there giant killer potential in these? Maybe be giant brand killer? Boy that would be fun to see.

The only thing I don't particularly like is the chain adjustment "plastic" and pull start with its mini rope...they screem cheapie.

 

[cbr929rr]

I just added a 1/4 inch hole in the front of the muffler and adjusted the carb on my 33cc homelite ranger, I also added a 12" bar and non-safety woodsman chain. Mine was bought new and did not have limiter caps, but i needed to make a to make a tool to turn the mixture screws with brass tubing. Saw runs 100% better!! Thanks to the people on this site!!

 

[Al Smith]

Little saws are a hoot to pep up.Tiny little things that sound like a swarm of bumble bees on steroids.At a GTG at Woodjunkies ,Gyp and Big Dave had two little giant killers on tuned pipes.It fascinated me so much that I piped a mini Mac.These are just big kids toys but they have the heart of a lion.

Even without a tuned pipe you would be surprised at how much you can coax out of them.Another neat thing about little saw is the fact that often you can find them at garage sales and auctions usually cheap.If a person wanted to experiment with porting,these would be a good cantidate.If you screw one up,you aren't out much money.