2 STROKE WORLD .net

The 2-Stroke Garage => Turning Wrenches => Topic started by: PhilMill63 on October 02, 2026, 11:50:50 AM

Title: Questions on 350 upgrade.
Post by: PhilMill63 on October 02, 2026, 11:50:50 AM
I am putting the 350 top end on my 79 250E, the bike had 2R8 barrels but 1A0 carbs, I assume that makes no difference as I'm changing the top end? is it worth putting 2R8 slides in and where should I start with jetting? its got standard airbox currently with all snorkels but wonder if they should be removed??
Second question, I want to get expansion chambers, so should I be looking for 250 or 400 ones? will there be much difference in performance with one over the other? Thanks.
Title: Re: Questions on 350 upgrade.
Post by: m in sc on October 02, 2026, 12:25:17 PM
chambers are more related to stroke, so go for250/350 ones.

as far as carbs..  depends its sort of a Hodge podge. id baseline wirh 250 jetting but up the main by 3 or 4 sizes from there.
Title: Re: Questions on 350 upgrade.
Post by: PhilMill63 on October 02, 2026, 02:50:54 PM
Quote from: m in sc on October 02, 2026, 12:25:17 PMchambers are more related to stroke, so go for250/350 ones.

as far as carbs..  depends its sort of a Hodge podge. id baseline wirh 250 jetting but up the main by 3 or 4 sizes from there.

Good info, thanks.