Wiseco Big Bore Kit

[James England]

Why would anyone advertise this way?????

The same kind of idiot that puts a generic picture of several different pistons, along with a disclaimer that effectively says 'ignore the picture'. Totally daft.

[crazy steve]

I believe the only rebuild parts still available are main bearing inserts and some valves, and those are spotty. Rod bearings are extremely hard to find (pretty much NOS that have been found in 'dealer kits' when on the rare occasions you do see them), same goes for 'genuine Yamaha' pistons and rings. I haven't seen a ring set in years, you'll see the odd piston or three on eBay once in a while in the various factory oversizes; try putting together a matched set....

There just isn't enough market to warrant anybody tooling up to make replacement parts. Tony (geezer) at OMP had a short run of both early and late valve sets done and barely sold them all.

[ViperRon]

80-81 Yamaha XS1100 1196cc Bigbore Piston Kits with Head Gasket XS1100BB -
This is the over bore kit I got of ebay and installed in mine.It has run fine came in good quality and a much cheaper price than the Weisco or Yamaha kit. I do not feel that it is worth spending the money looking for power gain but if the lower part of engine is good and head maybe as cheap a rebuild as possible. There is always another solution also. If you can find good cylinders just re-ring the old pistons. The actual round cylinders do come out of the 4 cylinder assembly easily. So say you just have one bad cylinder just replace that one.

[MPittma100]

Big Bore Kit

Since we all are so highly impressed with this "one piston" advertisement, I decided to send the following comment to that seller.

"Why would anybody buy just one piston kit? Answer: Because he was mislead by your advertising showing a picture of more than one kit. It is people like you that give Ebay a bad name. I and all of my forum members now know of this scam. You can count on us buying piston kits from someone else when/if needed."

The intention of my comment is to encourage this seller to redeem himself with an ad correction. We will see if I am wasting my time.

[crazy steve]

Don't hold your breath..... Makes you wonder if he has a incomplete set he's hoping to get rid of....

[Dan Hodges]

Cubic Inches

A Wiseco 1179 big bore kit is worth over 10% more power all other factors equal. The latest Wiseco forgings have anti detonation groves and thinner rings (less ring drag) than the stock pistons and have a 6.6 cc dome and of course they are lighter than the stock slugs.

It's also worth mentioning that the earlier Wiseco pistons for the XS were a different design and didn't have the anti detonation groves, trick rings and some other features the current pieces have and too make a long story short, the latest Wiseco pieces are state of the art but they aren't cheap and it's up to the owner of the bike as to what he/she want's.

A head clean up with a valve job, new springs and OEM valve stem seals and the head is good to go.
You will also need to have the block bored and honed (properly) by a shop that can finish the bores with the finish prescribed by Wiseco otherwise the rings will take forever to seat properly if ever.
Again, if you are going to spend the money on trick pistons make darn sure you don't let some idiot dry hone your block.

I had Advenced Sleeves in Ohio prepare my blocks but there are other shops who are equally competent.

A set of early cams and the late head with the above parts will fetch 85 conservetive rear wheel hp with the stock carbs, Dyno Jet kit, stock air box and stock or similiar type mufflers.

If needed, rod and main bearings can be found if you really want them but you might have to polish the main bearing journals of the crank to match up the correct clearences with the available bearings.

Of course you can buy a junk motor from a junk yard and as long as it doesn't whine, jump out of gear, smoke or catch on fire you are good to go as long as you are not in a hurry.

Happy motoring!

[MPittma100]

Big Bore

Thanks Dan Hodges. Good information.

[MPittma100]

Stock Rear Whel HP

Dan, what is the rear wheel horse power of these bikes in stock configuration?

(Quote) A set of early cams and the late head with the above parts will fetch 85 conservetive rear wheel hp with the stock carbs, Dyno Jet kit, stock air box and stock or similiar type mufflers.

[D0wn5h1ft]

Dan, what is the rear wheel horse power of these bikes in stock configuration?

(Quote) A set of early cams and the late head with the above parts will fetch 85 conservetive rear wheel hp with the stock carbs, Dyno Jet kit, stock air box and stock or similiar type mufflers.

Yeah, doesn't the old magazine article say 95 bhp stock?

[MPittma100]

Hp

Yeah, doesn't the old magazine article say 95 bhp stock?

Yes, that 95 HP is engine (at the crankshaft). Normally you get about 85% of crankshaft HP at the rear wheel. That percentage will vary.

[Rasputin]

Or If one wants to buy a kit there is Amazon http://www.amazon.com/s/ref=nb_sb_no...20kit%20xs1100

[dpotter58]

Always read the description closely. It does say "1" of each. piston, ring set, ect... not "4" of each.

[rambler Shawn]

"The large print giveth, the small print taketh away." -Tom Waits

[Dan Hodges]

Dan, what is the rear wheel horse power of these bikes in stock configuration?

(Quote) A set of early cams and the late head with the above parts will fetch 85 conservetive rear wheel hp with the stock carbs, Dyno Jet kit, stock air box and stock or similiar type mufflers.

73-80 depending on the model.

[trbig]

If you just put in early cams with a late head and aren't changing all the timing components and electronics as well... You've just lost a ton of useable HP and created a lead-sled of a bike with zero low end torque. Been there/done that.

A fresh engine using the 1179 Wiseco kit, a cleaned up head, 3 angle valve grind, and all new bearings, guides, and seals throughout, Dynojet kit, and stock exhaust resulted in.. a fresh motor with zero percieved HP gains. But.. I had a motor I knew was good to go for a considerable time.