024/026 Frankensaw Project

[Mad Professor]

Its alive! Barely, but it makes noise. I think it'll run fine once I get the rest of the pieces on there and tune the carb. Here's a video of it running. This is with the WT-194, btw.


If you watch, you can see a screw pop off when I first rev the saw. This is where it came from.

I guess I'll have to drill and tap the hole. I don't think I have a tap that small. Hopefully there's one at the shop.

I thread insert (helicoil, timesert) will be more durable than hogged out magnesium threads.

 

[Mad Professor]

Not to hijack this thread but what to saw builders/modifiers prefer for cylinders on the 024S/026/260.

The older 44mm or newer 44.7mm?

Although smaller I've heard good things about the smaller 44mm (ports and compression), vs new 44.7mm.

 

[nstueve]

44.7mm has lower compression and worse port timing from what i've read. Anyone who wants to build a 026 and do pro porting will go for a 44mm cylinder with "D" shape combustion chamber. The "newer" 44mm cylinders have more of an oval combustion chamber so you have to be lucky to find a old school 44mm"D".

I've found 2 out of the 2-3 dozen 026/260's i've rebuilt. 1 was DOA and the other had been so over ported by someone with a dremel that it's probably ruined. I might give it to shaun to see if he can save it from the scrap alum pile.

 

[PogoInTheWoods]

44.7mm has lower compression and worse port timing from what i've read. Anyone who wants to build a 026 and do pro porting will go for a 44mm cylinder with "D" shape combustion chamber. The "newer" 44mm cylinders have more of an oval combustion chamber so you have to be lucky to find a old school 44mm"D".

Wouldn't those same differences then also be inherent in the aftermarket 'knock-off designed' top end kits? Just curious....

opcorn:

And props to the OP for getting some initial satisfaction out of his effort!

 

[SawTroll]

Agreed on the carbs. I just find it interesting that a WT-22 is often overlooked as a perfectly adequate, fully adjustable carb as a replacement for the fixed-jet carbs on even a moderately modded 026. Heavily modded? Go with the extra fuel flow of the WT194 -- and pay the extra $$$ it's gonna cost.

As for bore, let's not forget the later 44.7mm version.

The WT-22 has only a 12.7mm venturi, while the WT-194 has 13.49mm venturi (still small on a 50cc saw, but better).

 

[nstueve]

The WT-22 has only a 12.7mm venturi, while the WT-194 has 13.49mm venturi (still small on a 50cc saw, but better).

the 194 feeds enough gas to a woods ported 026 just fine, and the wt22 feeds any stock saw just fine as well. If you are staying stock it doesn't matter what carb you use as long as it's not a fixed high jet carb. The only upgrade after a 194 is a carb off a 044 stihl which is a big modification and you almost need to be race ported to run a carb that big. When you can 4stroke at 12,000-12,500rpm you've got a carb big enough to feed the saw.

 

[H 2 H]

the 194 feeds enough gas to a woods ported 026 just fine, and the wt22 feeds any stock saw just fine as well. If you are staying stock it doesn't matter what carb you use as long as it's not a fixed high jet carb. The only upgrade after a 194 is a carb off a 044 stihl which is a big modification and you almost need to be race ported to run a carb that big. When you can 4stroke at 12,000-12,500rpm you've got a carb big enough to feed the saw.

The 194 is the one that's on the saw I rebuilt for myself and the ones I rebuilt for others this year :msp_wink:

 

[nstueve]

Wouldn't those same differences then also be inherent in the aftermarket 'knock-off designed' top end kits? Just curious....

opcorn:

And props to the OP for getting some initial satisfaction out of his effort!

the problem with AM cylinders is that even in the same run a cylinder can have a squish of 0.020 or 0.035 which is a HUGE difference when your talking compression. I've used some AM cylinders at customers request to save money and always have problems getting a good squish set so the saw will have enough power. I don't professionally port cylinders like some but I would venture to guess that if the squish is off that far then the port timing could be close to OEM but might not be also... You get what you pay for when it comes to cylinders. If you want a good aftermarket cylinder you need to get a good brand like NWP from Baileys and even then you are taking your chances. There are some good companies like Meteor that make complete P&C combos and they are as close to stock as your going to get. $40-$50 P&C's off ebay are usually riddled with voids in casting, rough transfers, intake, and exhaust. Heck I even got a chineese AM 026 cylinder from ebay once that had a huge void in the spark plug threads! Think that might be dangerous??? That being said I have seem some good AM cylinders for 029/039 stihls. Not sure if it's a different manufacture but quality is hit and miss and is the reason why the guys who do port work usually don't like to do it on AM cylinders unless it's for fun or for themselves...

to answer your quesion I would venture a guess that most chineese cylinders don't have stock port timing. If you want to run am cylinders I hope you have a dremel handy to clean the problems up before install (if they are problems you can fix). Also watch the pistons too... I just got a 046 AM kit that had voids in the casting on the piston skirt. And while some might find it good to have a "molly coat" on the piston skirt to help break it in... I suspect it's just like painting a cheap bar... it's done to cover blemishes and problems in the cast metal/alloy. check your parts over really well and if you find problems contact the seller for a refund or replacement and let them know you got bad parts.

 

[nstueve]

The 194 is the one that's on the saw I rebuilt for myself and the ones I rebuilt for others this year :msp_wink:

you know I never thought to actually look... I am wondering what the venturi size is on the auto comp carbs on the ms260's???

Gritz,
would you put a dial caliper on the venturi's you have and list their sizes and models??? I know you have several of the newer/Pro style from the pics you have. I'd be interested in knowing what the ventui is on the wt-427 since I know thats one of the fully adjusable pro carbs... Also you us a dial caliper to measure you piston width or cylinder bore to figure out whether you have a 44mm or a 44.7mm.

 

[H 2 H]

you know I never thought to actually look... I am wondering what the venturi size is on the auto comp carbs on the ms260's???

...

You mean WT427 or WT-403A they work also but off hand don't know the sizes

Like they told me you can put just about any carb on as long as you have the $$$$$$$$$

 

[gritz]

Okay, got the helicoil put in and the muffler is no longer loose. I made a quick video cutting a couple chunks off a stump I had just to play a bit. This was with a 13" bar. I need to get a 16 or 18" bar and put on it (forgot to grab one from the shop earlier) and get an actual log and stand so I can make some real test cuts. I was surprised at how loud this thing is for its size. I think it's louder than the 045 I've got, lol. Here's the video:



I wanted to push harder, but that little sawhorse wanted to tip on me. When I dug the dogs in to pull into the wood, it responded much better. I think a 16" bar would be perfect for this little saw.

 

[gritz]

you know I never thought to actually look... I am wondering what the venturi size is on the auto comp carbs on the ms260's???

Gritz,
would you put a dial caliper on the venturi's you have and list their sizes and models??? I know you have several of the newer/Pro style from the pics you have. I'd be interested in knowing what the ventui is on the wt-427 since I know thats one of the fully adjusable pro carbs... Also you us a dial caliper to measure you piston width or cylinder bore to figure out whether you have a 44mm or a 44.7mm.

I picked up a WT-22 carcass today when I was at the shop. I'll measure all the venturis tomorrow and post up a full report on my findings. Hopefully I can get all of those different carbs to run and then I can do some test cuts with each different carb on the same saw and we can figure out which one runs the best.

 

[gritz]

@ nstueve

I measured all the carbs today. All of them were pretty similar except the WT-22. It's Venturi was smaller than the others. Interesting, huh?. All the rest only varied in size by a half a millimeter or so. I wrote the sizes on each carb. The order fro top left to bottom right is as follows. WT-22B, WT-426A, WT-194, WT-394, and WTE-5.

Choke/Air filter Side (measured at smallest part of the venturi)

Throttle/Cylinder side

Now I have to try all these out. I wasn't planning on rebuilding them all, but now I guess I have to to find out which one is best. I have more kits and needles on order. Hopefully they will be in this week.

 

[H 2 H]

@ nstueve

I measured all the carbs today. All of them were pretty similar except the WT-22. It's Venturi was smaller than the others. Interesting, huh?. All the rest only varied in size by a half a millimeter or so. I wrote the sizes on each carb. The order fro top left to bottom right is as follows. WT-22B, WT-426A, WT-194, WT-394, and WTE-5.

Choke/Air filter Side (measured at smallest part of the venturi)

Throttle/Cylinder side

Now I have to try all these out. I wasn't planning on rebuilding them all, but now I guess I have to to find out which one is best. I have more kits and needles on order. Hopefully they will be in this week.

THX for the info :biggrin:

 

[gritz]

THX for the info :biggrin:

No problem.

 

[gritz]

So, I need some opinions. I want to send my Dad a reliable saw and I've got two saws that I'm piecing together right now while I'm waiting on the carb kits and needles. One will be a stock cylinder in descent shape, the other will have a new aftermarket cylinder. Which one would you rather have? Also, for you guys that have the plastic handle on the 024/026, have you had any reliability issues? He said he doesn't need the heated handles, so I'm not ordering any new handles and can't decide on the plastic or aluminum handle. I figured the plastic would hold less vibration than the aluminum, possibly. I appreciate your help.

 

[Stihlofadeal64]

So, I need some opinions. I want to send my Dad a reliable saw and I've got two saws that I'm piecing together right now while I'm waiting on the carb kits and needles. One will be a stock cylinder in descent shape, the other will have a new aftermarket cylinder. Which one would you rather have? Also, for you guys that have the plastic handle on the 024/026, have you had any reliability issues? He said he doesn't need the heated handles, so I'm not ordering any new handles and can't decide on the plastic or aluminum handle. I figured the plastic would hold less vibration than the aluminum, possibly. I appreciate your help.

I'd personally want the stock cylinder. As for the handle I don't have a preference. Never noticed any difference in either to speak of. In the video when you ran the saw through the chunk -- how did you tune the carb? Do you have a tach? Just wondering, I never really hear it 4 stroke but I may have missed something. Sounds like you are well on your way with these saws. Congrats

 

[Boogieman142]

awesome job man. I built my father a 260 few years back when his 142 died as well. mine was only made from 2 saws tho.

 

[gritz]

I'd personally want the stock cylinder. As for the handle I don't have a preference. Never noticed any difference in either to speak of. In the video when you ran the saw through the chunk -- how did you tune the carb? Do you have a tach? Just wondering, I never really hear it 4 stroke but I may have missed something. Sounds like you are well on your way with these saws. Congrats

That seems to be the opinion around here - stock cylinder. I think if I replace all the seals and rubber pieces, then he should be able to run for a long time without any issues. I can use the aftermarket cylinder to play with porting and such. As far as tuning, it was 4-stroking, but I didn't really get it into enough wood to hear it smooth out in the cut. You can kind of hear it a little in that last cut I made , but I couldn't push any harder or my stand would have fallen over (look at the back left leg, lol), and the chain isn't the sharpest (sharp enough, but not my typical standard). I took it out and cut down a birch with it and it ate it up and felt real nice (I know just about anything eats right through birch). I think if I put a 16" bar on it, it will be a really nice machine for Dad. I rarely use a tach. I tuned a batch of husqvarna trimmers the other month (they apparently don't start them at the factory, two wouldn't even start without adjustments). They all were tuned by ear and I was within 100 rpm on all of them (14). I think that's an acceptable amount of variance. I was a band nerd before I started working on saws, so when I tune, I listen for tone as much as tune. It's impossible, in my opinion, to actually hear what it's supposed to sound like in a video. Maybe in a recording studio, but a typical saw is more than likely too loud. And I'm rambling again.....

 

[cutforfun]

W

I'd personally want the stock cylinder. As for the handle I don't have a preference. Never noticed any difference in either to speak of. In the video when you ran the saw through the chunk -- how did you tune the carb? Do you have a tach? Just wondering, I never really hear it 4 stroke but I may have missed something. Sounds like you are well on your way with these saws. Congrats

I agree with the saw may need tuned a little richer it sounded like it is running to lean