Worn T350 pistons/barrels

Whenu · Posted: Tue Jan 11, 2011 2:31 am Post subject: Worn T350 pistons/barrels

Hi, my 1971 t350 has worn pistons and rings. It's on the O/size pistons now.
Anyone know where a set of barrels either std or o/size can be obtained?
Or conversely, another solution, cheers, Whenu

Bikegeezer · Posted: Wed Jan 12, 2011 6:27 am Post subject: Re: Worn T350 pistons/barrels

rdaystrom · Posted: Wed Jan 12, 2011 11:03 am Post subject:

O size pistons doesn't mean anything to me. As far as I remember Suzuki pistons come as std, 0.5mm, 1.0mm oversize and on up. If you are considering boring your cylinders be sure you get a qualified machine shop that is familiar with boring 2 cycle motorcycle cylinders. Be sure they bore it to the exact factory clearance which you will need to provide from your own research. (Perhaps someone on this forum can provide the factory clearance specification.) Do not let them bore it to their own specs because they do not know the specs. They guess at piston skirt clearance lot of the time. If it is slightly loose it will have noisy ring-a ding piston slap and too tight will seize up. Do you get my point here? Piston to cylinder clearance is a super big deal with 2 strokes. Not just for performance and wear characteristics but for a quiet engine as well. Two cycle cylinders that are re-bored need special (smoothing) attention to the port edges to prevent piston ring damage. It might be worth the extra expense to ship the cylinders off to a well known qualified machine shop for that type of cylinder as opposed to using the local shop that will likely ruin your cylinders. I have seen so many cylinders ruined.....good luck with it. There are quite a few pistons on Ebay.

Whenu · Posted: Wed Jan 12, 2011 6:48 pm Post subject:

Yello, from what I can understand, there is only the one oversize for these motors, so once you get too worn, there's not alot that can be done, the mechanic is very experienced on two-stroke motors.

Freaky_1 · Posted: Wed Jan 12, 2011 7:47 pm Post subject:

sizes =

Std
0.5mm over
1.0mm over

and some still list 1.5mm over, but I seriously doubt they actually have them. These were supposedly R-spec items. Can't say either way on them as I've never seen any.

I have some of each of the other 3 sizes though. I've got 2 sets of standard, 3 (one NOS) .5 and 3 (all NOS) 1.0 oversize.
I picked these up a little alone over the summer, collecting parts for 3 T250s. I've got 2 T350 engines, so nothing's for sale, just sharing what I've found in the past few months. I'd have to dig online to see what's readily available, all of mine have come from just buying parts from individuals.

OH, can't speak for rings yet, Only have one piston's worth and don't remember which size.

rdaystrom · Posted: Wed Jan 12, 2011 10:26 pm Post subject:

Suzuki oversize pistons are large enough to clear almost any wear. They are in 0.5mm increments. Rarely (on a Suzuki) does one need to go from std. straight to a second oversize because of excessive wear. There are several oversize pistons available just on Ebay not to mention other online sites. If your bike is in a Suzuki dealer they may not go to the trouble to find these older parts. Because finding vintage parts is a little more work they would rather just tell you they are not available.