Is there a noticeable difference in the size of the carb, the air intake and air filter between the 257 and the 262? The 257 parts seem too small to flow properly for a 262.
Husqvarna 257/262 carb, intake and air filter differences?
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In a word, yes.
The carburetor is the same but all the other intake components are the from the 254.
Apart from the size differences, If you're putting a 262 cylinder on a 257, you'll find that air filter mount doesn't sit flush with the top deck of the crankcase, because the 257/262 conrod is longer than the 154/254 rod.
The carburetor is the same but all the other intake components are the from the 254.
Apart from the size differences, If you're putting a 262 cylinder on a 257, you'll find that air filter mount doesn't sit flush with the top deck of the crankcase, because the 257/262 conrod is longer than the 154/254 rod.
I see, so if the carb has the same venturi size that would be the main limit to airflow.
The need for washers to seat the air filter mount properly is because of the slight difference in angle on the cylinder mounting face.
I have read about larger carb upgrades for the 262, but with the 257 plumbing upstream and downstream, this would be futile as they are sized too small to take advantage of the size increase.
I was wondering if anyone (spike 60?) has ever directly compared the sizes of the carb mounting components between the 257 and the 262 to see if the latter is sized larger for better flow.
The need for washers to seat the air filter mount properly is because of the slight difference in angle on the cylinder mounting face.
I have read about larger carb upgrades for the 262, but with the 257 plumbing upstream and downstream, this would be futile as they are sized too small to take advantage of the size increase.
I was wondering if anyone (spike 60?) has ever directly compared the sizes of the carb mounting components between the 257 and the 262 to see if the latter is sized larger for better flow.
You do seem to have your head around all the issues. As long as the higher position of the air filter mount doesn't cause the top of the filter itself to interfere with the top cover, I think you should be ok.
I remember Bob (spike60) in an HTSS video showing a 257 he'd fitted with a HUZTL 262 cylinder so he should know all about it. (As you're probably aware, the big mistake is to fit a 262 cylinder on a 254 without also changing the crankshaft.)
The 257 was conceived as farm/semi-professional largely using existing 254 & 262 parts, the top cover and Gilardoni cylinder & piston being the only unique components.
I remember Bob (spike60) in an HTSS video showing a 257 he'd fitted with a HUZTL 262 cylinder so he should know all about it. (As you're probably aware, the big mistake is to fit a 262 cylinder on a 254 without also changing the crankshaft.)
The 257 was conceived as farm/semi-professional largely using existing 254 & 262 parts, the top cover and Gilardoni cylinder & piston being the only unique components.
