Newbie (on the site) with a engine problem.

bkf_uk · L Plate Warrior Joined: 15 Jun 2009 Karma :

Hello all first post and wonder if you can help.

I Recently bought a poorly suzuki gn250 that had a neglected top end.

Have had a number of project bike over the past 6 years and am happy to rebuild a engine.

Fully stripped and re-built the top end, having found a destroyed valve guide and bent valve, all new guides and gaskets all round.

When i first started the engine after rebuild as expected a giant white cloud of choking smoke poured from the exhausts and then finally cleared. however have let the engine sit for a day or two and again it starts with a choking thick white cloud (oil been burnt).
Sick

My question is where the hell is the oil coming from? it's been fully rebuilt!
Brick Wall

Any ideas are most welcome!
Bryan

Ariel Badger · Super Spammer Joined: 02 Dec 2006 Karma :

It can only come from two places, past the rings or down the guides. As it is a start up problem I say check the guides and any seals. How does the plug look?
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Bikers make great organ donors, get 115 on your licence today.

bkf_uk · L Plate Warrior Joined: 15 Jun 2009 Karma :

plug is new but showing signs of a nice brown colour, the guides and seals are brand new, they where replaced after finding one was shattered.

Ariel Badger · Super Spammer Joined: 02 Dec 2006 Karma :

If you are certain that the top end is ok it must be the bore or rings.
____________________
Bikers make great organ donors, get 115 on your licence today.

bkf_uk · L Plate Warrior Joined: 15 Jun 2009 Karma :

i think ill give the old trick of an "italian Tune up" a shot first before ripping the infernal thing apart again. Although the engine looks like it was rebored not too long ago, but the bike has got 70k miles on it!

steo · Nova Slayer Joined: 08 Jun 2009 Karma :

if the engine needed a rebuild after you bought it then there's a good chance that your exhaust is clogged up with burnt waste oil from then old engine thus giving you the impression that there's a problem with your new rebuild. as the gn have a sealed exhaust you cannot take the baffle out to clean it. before you consider taking the engine apart, do a compression test or if you can get hold of another exhaust, try that.

iooi · Super Spammer Joined: 14 Jan 2007 Karma :

bkf_uk · L Plate Warrior Joined: 15 Jun 2009 Karma :

valves where lapped in to the head by the company i had fit the guides. The exhaust was also replaced and is brand new, therefore it shouldnt have any oil inside at all. Started the bike again today and it was much cleaner, but still a bit of white smoke.

The oil and filter are new, as are most components with the bike. it's had a full stirp down and rebuild.

Could a bad batch of petrol cause this? the only reason i ask is i used the same petrol in my lawnmower (standard 95ron unleaded from a supermarket) and it was running lumpy as hell, in fact come to think of it, filled the car up at the same time and it isnt running right either?

steo · Nova Slayer Joined: 08 Jun 2009 Karma :

this is going to sound like a silly question but did you happen to put diesel into your fuel tank or use it in anyway shape or form for cleaning or use a similar product?

bkf_uk · L Plate Warrior Joined: 15 Jun 2009 Karma :

No diesel, petrol was straight from the pump. but am starting to wonder if it was contaminated. cant get the car to idle properly.

Will get some fresh petrol from a different source and flush the tank out to see if it makes any difference.