Is it also likely that a previous owner could have made the modification?

I have three 1VJ engines - all 34k00 y1 barrels - two of them have 30mm holes on cam side and 40mm holes on other side. All bolts are 105mm

The other engine -- holes are all 5mm deeper - bolts longer.

PS::: Is that the STANDARD original piston???

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no its a new replacement oem spec .75 oversize





the old one


the worn bore and piston was letting loads of oil past

cheers

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http://picasaweb.google.co.uk/andypackham
http://www.youtube.com/user/yahyajammeh

Oh HA HA!

I recognise that old piston!! (from your other post!)

How has it all gone, by the way??

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all back together and no smoke now

not sure what sort of running in is recomended on a rebore & new piston?

next on the list of things to do is

sort out carbs - i've got another pair to try out and fiddle with.

sort out excessive vibes (really bad over 50mph) - not sure where to start with this, can anyone can give me a list of things to check engine wise?

and when its all running right I'll look at cosmetic stuff

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http://picasaweb.google.co.uk/andypackham
http://www.youtube.com/user/yahyajammeh

For the excessive vibes you have to go cosmetic! lol

Replace the XT's stock front fender with one of those from the YZ or WR!

makes a humongous difference on the vibes at higher speed!


Vando

when running in use cheaper oil don't use synthetic try and keep the revs down short shift when possible when you have done 250 to 300 miles change the oil and filter then ride pretty much as normal but try and avoid sustained high rpm's though until you have covered at least 500 to 650 miles since the rebuild do another oil and filter change if you want to.
i'd do an oil and filter change at 1000 miles if you don't do one at the 650 mile mark after that your done with running in these big singles don't need that much running in.

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XT 630 SUPERMOTO

GSXR750L KMX200

RF900 & GSX400X Impulse Projects
3.9 V8 Rangerover

If you say to put cheap oil just because it is expensive as you need to change it on the first few couple hundred miles you make a good monetary point...

BUT in terms of engine reliability, USE THE SYNTHETIC OIL and try to always use the same oil as changes in different oils will lead to a decrease in reliability!

In the first few hundred miles do as wolfzero said, when changing the oil also change the oil filter!

Don't sit on the throttle in the same position for too much time and go easy on the engine, use all your gearbox up to a little over mid range. Do not rev the engine too high.

Try to avoid speedways..bad bad bad for the break in when done wrong!

When you get 175-200 miles on the clock do push the bike from once in a while with a minimum of 50-100 miles difference!
Make a stop, engage 1st and juice it all up till 5th without revving the gears too much.
When you're just a little below top speed start slowing down but not too harshly! (AND DON'T engage the clutch while on top speed and go down from 5th to 1st like I've seen some dumbarses doing!) Use gearbox braking and the brakes!!!!

I am tho a little more carefull as between oil changes especially during break in...
When I replaced the Piston, piston rings with some wider ones, camshaft and chamshaft bearings on my 2002 DT125R I changed the oil at 300 miles, 600miles, 1200miles, 3000miles and finally at 7000 miles and every other 4000 miles!
It now has almost 70000 KM on the clock from which 40000 have been done with the recent engine work.... And I'm everything but gentle with that bike!

Vando

Thanks, I'll stock up on a few oil filters and I'll have to guess on the mileage as my speedo works but not the mileage... (stuck on 54,000 not sure how long its been like that)

I dont want to start an oil debate but I'm using the semi synthetic from Heine Gerrick as its cheap. some have said fully synthetic messes up the clutch, not sure on that one.

any idea's on the stuff to check on engine regarding the vibes?

nice supermoto by the way, I'm amazed at corner speed & turn in on my 25yr old XT with Scorpion & Distanzia, yours must be a lot of fun.

cheers

__________________
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