290 Piston Kit Fitment

[supermotodaz]

Can anyone shed anymore light on this subject, are the earley 290 Bultaco sherco,s the same fitment piston throughout to the later range of Sherco 290, or was there a change over year.

Cheer,s

Daz

[copemech]

Can anyone shed anymore light on this subject, are the earley 290 Bultaco sherco,s the same fitment piston throughout to the later range of Sherco 290, or was there a change over year.

Cheer,s

Daz

The only difference I am aware of is it seems some pistons may have a cutaway in the rear skirt and others not, but that in itself makes no difference in performance.

A glance through the 99-00 parts books and I did not find the 2.9 piston listed? All the same, best to ck with the importer to be sure.

Roumour was it was the same piston as Beta 270, and many pistons still said Beta on them in the casting.

Precise fitment depends upon the A-B-C sizing variences, so you must ck top piston stamping letter to be sure.

[tony27]

The only difference I am aware of is it seems some pistons may have a cutaway in the rear skirt and others not, but that in itself makes no difference in performance.

A glance through the 99-00 parts books and I did not find the 2.9 piston listed? All the same, best to ck with the importer to be sure.

Roumour was it was the same piston as Beta 270, and many pistons still said Beta on them in the casting.

Precise fitment depends upon the A-B-C sizing variences, so you must ck top piston stamping letter to be sure.

I can confirm that rumour Cope, I'm running a beta piston in my bike as the importer is a good friend who gave me 1 as payment for some work I'd done for him. Figured 5 years of hard use was almost enough for a piston, measured okay still though

I had a beta piston in my 01 as well.

From what I've seen Vertex use a insert in the mould that they change depending on who the order is for which should bring the cost down for both manufacturers

[zippy]

The only difference I am aware of is it seems some pistons may have a cutaway in the rear skirt and others not, but that in itself makes no difference in performance.

A glance through the 99-00 parts books and I did not find the 2.9 piston listed? All the same, best to ck with the importer to be sure.

Roumour was it was the same piston as Beta 270, and many pistons still said Beta on them in the casting.

Precise fitment depends upon the A-B-C sizing variences, so you must ck top piston stamping letter to be sure.

Yep the piston in my 2000 2.9 has Beta written all over it.

[trialsnutterman]

The early 250's originally came with a Mahle piston in which was later swapped to the Vertex one, the 290's have always had the vertex piston this changed slightly from year to year with the half moon shaped cut out as mentioned and also the later bikes now come with a special low friction coating on the piston, probably PTFE.

The 1999 bikes were 250's only.

[supermotodaz]

The early 250's originally came with a Mahle piston in which was later swapped to the Vertex one, the 290's have always had the vertex piston this changed slightly from year to year with the half moon shaped cut out as mentioned and also the later bikes now come with a special low friction coating on the piston, probably PTFE.

The 1999 bikes were 250's only.

Thanks for the info guys, yeah spoke to MRS , Martin was busy at the time so didn,t get a definate answer but as you say Vertex does them, didn,t know they were standard on the sherco,s , seen them on Gas Gas though as standard, i was more concerned with if the piston would fit all years as Vertex say all 290,s but only list as Bultaco Sherco, don,t mention years or later Sherco,s.

[zippy]

Thanks for the info guys, yeah spoke to MRS , Martin was busy at the time so didn,t get a definate answer but as you say Vertex does them, didn,t know they were standard on the sherco,s , seen them on Gas Gas though as standard, i was more concerned with if the piston would fit all years as Vertex say all 290,s but only list as Bultaco Sherco, don,t mention years or later Sherco,s.

Just received my top end rebuild parts for my 2000 2.9(barrel and piston) my old piston had Beta on the inside and my new one says Vertex. Not sure if that helps with whether or not they fit later year shercos.