One of these things don't look like the others...

[pKp]

Okay - stupid question of the month. I ordered two new pistons from BikeBandit.com and, three weeks later, they both arrived. It seems these two are not the same as the two they replace.

The motor, when I broke it down, had three identical pistons - stamped with ART on one side and 511 on the other. The pistons sent by BB, in Triumph boxes, had the ART, but 510 stamped on the side.

The parts manual calls for triumph 112000-TO301 for cylinders 1 and 3, and triumph 1120002-TO301 for cylinder 2. So evidently #2 is indeed different.

Am I okay to mix and match here? Cause other than the ART 511 marking I have no way to know what the part number of the remaining #2 cylinder might be...

[Jaythro]

If in any doubt weigh them and see what the tolerances are for weight difference

If you have 2 light ones and one heavy it will vibrate!

[BruKen]

I'd be a bit dubious and sceptical myself. In my experience recently in getting bits from Triumph is that they will give you whatever is on the shelf. The No2 piston according to the book of words should be marked, either with a B or a green dot, mine had neither. My endless chain came with a soft rivet...and the list continues. I'd splurge out a bit and replace all 3 rather than just two. Even if it's only for peace of mind.

[pKp]

Yea - I'm starting to think the previous owner may have gone to a high-compression piston - maybe from a Daytona? He did other "tweaks" as well - timing advance, performance exhaust, etc.

I've checked your rebuild, and other head gasket/cylinder sleeve change photos, and it seems everyone else has three pistons that look the same - even though #2 has a different part number.

Really - I don't mind changing it out...it's just the waiting on the parts that's the killer!

[coachgeo]

Instead of second guessing.... why don't you get a hold of the PO and ask him/her directly what was done different... and if so.... WHY.

They may have had a hell of a builder do that engine and it would be to your advantage to stick with the improvement plan used by the builder orrrrrrr.... PO got a screwball builder that muffed it up.  You won't know w/out asking.

[pKp]

Mystery solved. This bike was modified more than I suspected. The #2 piston in the photo is from a Trident-Daytona 750 - yields a slightly higher compression ration (11-1 vs 10.6-1 for Tiger 900). The PO had three of these installed almost out the door. Combined with advanced timing, carb tuning, and a great set of cans - must have been one great ride.

Unfortunately - short lived as the back of the pistons simply melted away on #1 and #3 at 18K miles.

Oh well - back to BB for another piston. This is getting expensive!