One Liter Plus Virago Pistons

As the reader may realize, pistons are the basis of engine performance. So if you want or need piston kits now or soon, you will have to cope with CP's or JE's turn-around time which is about a month. As always, having the engine torn down is an excellant opportunity for adding cam kits, carbs, and bending up a custom exhaust.

Available are piston kits with bored-to-size cylinders and an Athena gasket set. Figure an additional $400 for a 920. Thousand cylinders and gasket sets are costlier, so figure on $500 over the piston kit price.

At this point it may be a good idea to mention starting. All XV series bikes had marginal at best starting mechanisms. If your starter is weak, it is possible that it will spin without turning the bike's engine. See here.

Warning Warning Warning

The pictures above are of some 920 cylinders I had on hand. Note that the first two have no aluminum "dam" between the head gasket recess and that for the cam chain tunnel o-ring. These are blow-prone, and I recommend against even running an after-market cam with them, let alone a high-compression big bore. As near as I can determine, "good" cylinders (with barrier) were used in the XV920RH/RJ "Euro" and the XV920MK Midnight Virago. It appears that the good cylinders had a 5H1 part number and the bad were10L; I've had reports that there are exceptions to both numbers however. All our complete kits utilise the early style barrels with the barrier. When I buy cores, I ask for pictures first, and when I do get fooled, I pitch the errors on the scrap aluminum pile. TR1 owners note that this is a problem with your line as well. Finnish market '81s had good cylinders, Norwegian market '82s did not. You must check. One way around this is to get our complete kits with Virago 1000 cylinders - The compression is the same and the cylinder has a flat deck taking a single conventional head gasket. If we work out some kind of "exchange" deal on cylinders, do NOT send me barrels without the aluminum barrier. They are useless to me.

I invite the reader to peruse the CP-Carrillo website. Their pistons are low-silica, high-carbon and will not be as noisy while they warm up as the Arias were. These are quality pieces worth the extra cost. They may be of a better quality than your ride will ever test. If you plan on doing any racing, step up now. I consider myself fortunate that they decided to take on my lines. Due to their premium pricing, I will not keep any in stock - they will be special order only - figure four weeks. And if you want bored-to-size cylinders with them add two weeks.

96mm kits come with early style 920 cylinders; 99mm kits come with Virago 1000 cylinders. Sorry, those are the only cylinders I handle. Recommendations? 86mm (805cc) 12:1 kits for the 750. 96mm 11:1 for the 920s (and possibly for the TR1). 99mm 11:1 for the Virago 1000 and the TR1. 99mm 11:1 for the 1100 Virago. All these with at least the internal milling for faster spin up. 750 kits are priced as the 96mm, 1100 as the 99mm. The cylinders you get from me will be gloss black with exposed fin edges. They go through multiple curing and heat treating cycles so that they do not smoke upon first start up. Keep in mind that these are forged pistons: they will be noisy when the engine is not warmed up. You might think that there is a problem, but once they reach operating temperature they will be no noisier than stock.

I went down to the local industrial ceramic coating concern and asked a few questions and showed them some examples. I was appalled at the answers: if you want thermally disapative ceramic applied to your cylinders, it would run $350 for the pair. The ceramic is 'somewhere between matte and gloss' black. I wasn't shown any samples. I was told that it was no more conductive than bare aluminum; it just gives the coated part more surface area to shed heat. If you want this, check around locally; you may find it much less expensive.

I realize that the reader can attempt to buy directly from JE or CP. They have both measured my heads, stock pistons, head gaskets, and connecting rods. I gave them cam specs and projected max valve size. They both have four piston minimums and sell them retail for more than I have them offered - unless you can prove that you are a merchant of automotive goods. It took six documents and multiple pictures for both. They will probably refer you to me.

And yes, I looked at Wiseco, Venolia, Mahle, and a few others. I stand by my choices.

The pictures below are mostly obsolete showing the Arias pistons we formerly carried. Some show claying and help to illustrate how performance pistons differ from stock Yamaha. As the new pistons trickle in these shots will be replaced.