262XP Rebuild - Junk Pile Save

[XP_Slinger]

I’m not so sure the size of the uppers makes peak power lower. On Ryan’s KS cylinder I just finished, I barely raised them and didn’t widen at all.

I think they are going for velocity. In fact I think they have the transfers just about perfect on these for great scavenging! The next one I do I’m going to try cutting the jug so the transfers don’t need touched. Then adjust intake and exhaust accordingly.
But that’s just my theory...

It's all about learning and I've got plenty of that to do.

 

[paragonbuilder]

It's all about learning and I've got plenty of that to do.

Yep!
That is the fun of all this for me!

 

[Onan18]

I’m not so sure the size of the uppers makes peak power lower. On Ryan’s KS cylinder I just finished, I barely raised them and didn’t widen at all.

I think they are going for velocity. In fact I think they have the transfers just about perfect on these for great scavenging! The next one I do I’m going to try cutting the jug so the transfers don’t need touched. Then adjust intake and exhaust accordingly.
But that’s just my theory...

I like the way you think my friend.

 

[Onan18]

Howdy Joe...Just noticed you have a KS 262 in your sig. How does it run? Any work done besides having the holy grail of carbs on it?

Bone stock, the saw is minty and truth be told is a bit of a shelf queen. I only pull it out occasionally to blow the cobwebs out. It runs very well for a stock 60cc saw, truthfully though I like my other one with the 120 better. The 87 is a bish to keep tuned if running it all day, 120 is set and forget.

 

[XP_Slinger]

Bone stock, the saw is minty and truth be told is a bit of a shelf queen. I only pull it out occasionally to blow the cobwebs out. It runs very well for a stock 60cc saw, truthfully though I like my other one with the 120 better. The 87 is a bish to keep tuned if running it all day, 120 is set and forget.

I've heard that about the 87. I'm not racin so I'm ok with having the smaller carb, especially if it is more stable in its tune. Just because I know how to tune a saw doesn't mean I want to be re-tuning all day long lol

 

[paragonbuilder]

Bone stock, the saw is minty and truth be told is a bit of a shelf queen. I only pull it out occasionally to blow the cobwebs out. It runs very well for a stock 60cc saw, truthfully though I like my other one with the 120 better. The 87 is a bish to keep tuned if running it all day, 120 is set and forget.

That’s interesting. The one I built for @Boozer, has the 87 carb, and he’s never touched the screws since I set it. I wonder if ported makes a difference, or if it has an issue?

 

[Onan18]

That’s interesting. The one I built for @Boozer, has the 87 carb, and he’s never touched the screws since I set it. I wonder if ported makes a difference, or if it has an issue?

I am not the only one who has had this experience with a 87 on a stock saw, can't speak for ported.

 

[drf256]

Dont make the uppers big. Time the jug and see where they land.

Big uppers are a good way to ruin that saw.

 

[XP_Slinger]

Dont make the uppers big. Time the jug and see where they land.

Big uppers are a good way to ruin that saw.

I’m gonna leave them alone and run it stock before I goof around with it. Thanks for the advice Doc, between you and Dan I’ve learned a lot about this Saw recently

 

[drf256]

Was at work last night, but wanted to reply before you touched it.

Many of us can give you good 262 recipes. You’ll need machine work and also, you’ll need a 87 carb or equivalent. The 120/144 just won’t run as well once ported. Been there, done that. Dan and I both had ported 262 running against @malk315 MMWS262 mine had a 120 on it and lost badly. Swapped in an 87 tuned to the same rpm and mine was ther with the other 2. It actually DOES matter.

Keep the uppers small and tight. You want them to “spray” charge, not dribble it out.

 

[drf256]

Here’s Randy’s thread on converting a 199

http://opeforum.com/threads/making-a-walbro-hda-199-fit-on-a-262xp.3475/

Interestingly enough, a 346 comes stock with the same Venturi as the largest carb offered on a 262. No wonder they are tough to beat in a race.

 

[paragonbuilder]

Here’s Randy’s thread on converting a 199

http://opeforum.com/threads/making-a-walbro-hda-199-fit-on-a-262xp.3475/

Interestingly enough, a 346 comes stock with the same Venturi as the largest carb offered on a 262. No wonder they are tough to beat in a race.

I did not know that about the 346. Interesting!

 

[XP_Slinger]

Was at work last night, but wanted to reply before you touched it.

Many of us can give you good 262 recipes. You’ll need machine work and also, you’ll need a 87 carb or equivalent. The 120/144 just won’t run as well once ported. Been there, done that. Dan and I both had ported 262 running against @malk315 MMWS262 mine had a 120 on it and lost badly. Swapped in an 87 tuned to the same rpm and mine was ther with the other 2. It actually DOES matter.

Your advice is much appreciated Doc. This has been a good exercise in perspective for me, something I’ll try to carry forward. Not that I’d grind on a cylinder before running it stock, but when Dan and you said leave them alone it got me thinking from a different angle on what I thought I knew about transfer flow. And that is they will only flow as much as their smallest point. With those huge lowers I initially thought there was an imbalance between runner capacity and flow at the port window. Now, thinking from another perspective I see those big lowers as being kind of a plenum that stores volume with the small window releasing that volume at high velocity. I may still be off on that theory but that’s how I see it working until I prove myself wrong.

Having never run a 262 I’m excited to get this old girl going. I won’t be porting it before running it stock for a while like I’ve done with my 288 and 254, which are still stock. I suspect once the 262 is running I’ll be pretty darn happy with it and not be in a hurry to pull the top end just like with my other saws.

 

[XP_Slinger]

Here’s Randy’s thread on converting a 199

http://opeforum.com/threads/making-a-walbro-hda-199-fit-on-a-262xp.3475/

Interestingly enough, a 346 comes stock with the same Venturi as the largest carb offered on a 262. No wonder they are tough to beat in a race.

Yes sir! I went through that thread shortly after acquiring my builder. I’ll run the 120 while it’s stock, then switch to the 199 or maybe find an 87 when I decide to tear it down for porting. Little bonus in that is once the 262 gets a carb upgrade the 120 will be switching zip codes and getting installed on my 254 for an upgrade...win win

 

[drf256]

I’d venture to say that a properly ported 262 will keep up with your 288 with a 20”bar.

 

[XP_Slinger]

I’d venture to say that a properly ported 262 will keep up with your 288 with a 20”bar.

That would be impressive. If it does I guess I’ll have no choice but to port my 288 afterward lol!

 

[XP_Slinger]

Getting my parts order going with @Spike60 , if all goes well, I'll be putting the saw back together a couple weeks from now.

 

[Tor R]

I know @Tor R said that they beefed up the crank in I think 1993??? My saw is a 1992 so I believe I have the superseded crank.

View attachment 117712

View attachment 117711

02 cranks came in 1993 with a bigger con rod bearing:
257: 3360001
262: 3350195

254: 3360001

They upgraded oil pump and worm gear after those s/n's:
257: 3140001
262: 3450001
254: 3450001
Oil pump has a casting code J, or K, L or later code, it's openened up from 19.5mm hole to 22mm hole.

 

[XP_Slinger]

02 cranks came in 1993 with a bigger con rod bearing:
257: 3360001
262: 3350195

254: 3360001

They upgraded oil pump and worm gear after those s/n's:
257: 3140001
262: 3450001
254: 3450001
Oil pump has a casting code J, or K, L or later code, it's openened up from 19.5mm hole to 22mm hole.

Thanks Tor!

 

[RIDE-RED 350r]

262 I am trading with Dan for has a Mahle cylinder. I'm planning to replace the crank bearings, seals, etc just because she's an older saw. No mods or porting initially for me either. I do plan to time the cylinder and see where it is though. These 262 really have my attention and I can't wait to get mine!

Dan: that 262 in the vid you posted on the previous page looks great!