Any big gains to be made on a 660 carb? Or other 'low hanging fruit' for ported 660's?

[Cerberus]

I was astounded to see Zama carbs for like $20 on amazon (are there fakes or something?), and am well aware there's tons of carb-mods, so wanted to know- Does the 660 carb "leave real room for improvement"? If so, what areas are most common?
Thanks!!
(to be clear I mean for "moderately-hot woods ported" units, for instance my 56mm, 24.5thou squish, 99.5//81//125, 52thou before freeporting, piston-ported "super build", that one is running on my chinesium carb and my other unit, a regular woods-ported, higher compression 54mm pop-up around 101exhaust has a great walbro carb*, gotta say I cannot notice any difference both carbs are awesome, chinesium one suffered the "won't return to true idle" problem at first but that went away very quickly & never returned, thankfully!)
(*=great walbro carb thanks to the absurdly-generous MM, who I'm very indebted to as I'd never be able to play w/ this stuff if it weren't for him having gotten me started, "giving me a fishing pole" as it were but it was one I couldn't have afforded properly and therefore never could've been working a pair of units, constantly re-doing top ends etc having so much fun making ever-stronger units -- still haven't broken anything except a clutch-spring, knock on wood ;D )

 

[Cerberus]

(BTW to be clear....the 056 Stihl 56mm pistons do fit the 660 con.rod, correct? The crown height is off of course, but I only care Re fitment to the con.rod, want to verify -- also am VERY curious about whether 056 jugs fit onto 660 crankcases IE 54mm 056 jug on 660 crankcase?)

 

[smokey7]

Afaik the 056 fits the 066 rod pin. Compression height couldnt tell you. Jms a banned member here did a 056 jug and slug years ago on a guys say. I remember him saying it took lots of mods to fit. Problem is you cant trust what he said it needed to fit. It did run i think but who knows.

 

[Cerberus]

Afaik the 056 fits the 066 rod pin. Compression height couldnt tell you. Jms a banned member here did a 056 jug and slug years ago on a guys say. I remember him saying it took lots of mods to fit. Problem is you cant trust what he said it needed to fit. It did run i think but who knows.

It LOOKS like the Husqvarna 394 piston is gonna be "the one", still trying to verify it'll fit the con.rod properly (no excessive slop between gudgeon bosses on the interior, obviously a 12mm gudgeon/wristpin etc) and have more-than enough skirt to spare, which is basically the problem w/ 56mm 660's (even still, with the Wiseco's 56mm 660's obviously solving the prob I'm surprised those don't sell more...a properly done 99cc, 56mm ported 660 should be among the strongest configurations so far as power-per-pound of powerhead!)

 

[smokey7]

To put a expensive weisco in a china jug is unheard of. Weisco rings would likely eat the plating right up.

 

[Cerberus]

To put a expensive weisco in a china jug is unheard of. Weisco rings would likely eat the plating right up.

I know it's unheard of -- and the rings thing is simply chrome V nikasil, plenty of AM jugs are nika (or titanikel) plated..

It's unheard of which IMO sucks because, yes, it's a big price jump for "the 56mm kit" but it solves the problem of the skirts which is why the kits don't work for like 4/5 people (someone can please expand on this if I'm missing something, hell it's not even skirtS it's exhaust skirt or really exhaust port height, you can remake the intake easy peasy it's just the exhaust port doesn't work...but new versions have the exhaaust floor 60 thousandths higher on "NewJ's" brand so you can already not freeport w/ the short pistons, you could really work things w/ the Wiseco..


Or a 394 piston which I'm 99% sure is an OK solution, can't get a solid answer if it fits the con.rod or not :/

 

[redoakneck]

Back to the carb.

Increase the jet size from 69-73?? If I remember correctly???

More gas at full throttle

 

[cus_deluxe]

@Cerberus
If there was a stat for longest average post length, you would win.
Carry on.

 

[Gary Courtney]

@Cerberus
If there was a stat for longest average post length, you would win.
Carry on.

reminds me of an old Allman brothers song.

 

[JB-PlantHeirloom]

I have a carb on my FarmerTec (?) clone that is marked HL(icon)C, I want something different, hopefully better, and hopefully under $75.00.

This one is out of stock:
https://www.hlsproparts.com/Stihl-066-MS650-MS660-OEM-Tillotson-carburetor-p/hs-320a.htm

This is one is in stock, but, I assume this is the same carb as I have now:
https://www.hlsproparts.com/Stihl-066-MS650-MS660-carburetor-p/h20660.htm

Since Stihl owns Zima, I would not mind a OEM Zima, but, I do not want any Amazon clone junk, I rather buy local from my Stihl dealer who I like, but, as far as I can tell, they want $120+ for the carb.

Is there anything else that is good or recommended?

 

[Dennis Coon]

The 2 carbs wj67 and wj76 shown on the 660 ipl show . 64 mm and. 74 mm fixed jets respectively. I tried the bigger jets in both my mildly ported, muff modded, Maxflow saw and my stock but dual ported, maxflow and very early version (ie my favourite) saw and could feel no benefit and went back to the original jet in both.
Maybe it's just me, this is with shortish bars, 404 chain, in Australia

 

[JB-PlantHeirloom]

Thank you, I will see if it is possible to find a W67. as I have no plans to put any serious work into this particular saw.

 

[MustangMike]

Big Bore 660s (99 cc) have been made with both 056 P+C (spark plug location is different) and with AM big bore jugs and Husky pistons.

However, I believe TM developed more power by just putting a Husky piston in a standard bore 660 jug and widening the ports.

I'm sure things can be done to the carbs, but I have a ported AM 660 with the AM carb that came on it (unmodified) that dynoed at 8.6 Hp., so the carbs are not too bad.