Ok, iv'e narrowed down my problems to a few and i hope someone could advise me what i can do..
1.The engine used 1 Quart of oil in about 300 miles. Checked compression
They said it was 150 PSI sounds good to me... And no oil leak at all..
2.I get a really crappy performance from the engine. cleaned the carbs a while ago worked fine for a while but started doing it again  (used to run fine then crappy after a while  could suddenly return to normal after another 10 minutes.. but stopped working fine after a few times that happened)

So my thoughts about these problems are something like:

1. Really dirty valves or something like that ?
Can't come up with a really good Idea how to fix something like that
2. Dirty carbs? (I think my tank is a little rusty but not that much is that significant?) Does it matter if i run it always on PRIME instead of On (because of a bad petcock) will it add to the amount of dirt in the carbs?
Will a fuel additive like Bg's K44 do any good to fix that kind of problem?
Or is opening the carbs and cleaning them the only solution?

I would really appreciate any ideas on the first issue especially
And any good solutions for both!
Thanks.

First off, if there's rust in the tank, there's likely rust in the gas and some of it is going to get by the crappy tank screen. An inline fuel filter will help, but the only way to stop it is to fix the rust problem. The intermittent performance problem you described could very well be rust working it's way in and out of the fuel system. Could be a lot of other things too - hard to tell with limited information.

Next, these bikes use oil quickly, but a quart in 300 miles is excessive. Does the bike blow a lot of blue smoke out of the exhaust? If it's not leaking out, it's probably burning. Again, could be lots of things - bad rings or valves I'd think. What do your plugs look like?

Running the bike on prime won't make your carbs dirty, but you're constantly filling your carbs - could flood. I did this for a while because of a bad petcock and I ended up with a crankcase full of gas - not good. I don't know why that happened, but it could cause damage if you run it like that for long.

Fuel additive helps to clear out varnish and deposits - not physical rust or large dirt particles. Take 'em apart and do it right.

There are only about three ways to lose that much oil without a leak, that I can think of.

If the compression is that good, it unlikely the rings are the culprit, although it may be possble the scraper rings are screwed up while the other rings are OK. A leak-down test may be able to check the health of the rings further.

Do you get a puff of oil smoke when starting after it's been sitting over night? The other main path for oil lose is past the valve seals. They tend to leak down while the bike is sitting, so they will generally give a blue puff while starting.

The only other possibility I can think of is that the oil is going out the crankcase breather. This usually only happens if there is a lot of blow-by past the rings, which isn't likely if the compression is 150. Was there any oil in the airbox?

You didn't sound real positive on the compression test that was done - maybe it would be worth having it re-done at a place that would give the real number on each cyclinder, instead of  just a general "150".

Do you have an in-line fuel filter? If the bike runs fine after cleaning the carbs, it would seem that gunk is getting in them from the fuel. I'd clean the carbs again and put in a filter. It may be worth pulling the tank mounted petcock and the frame mounted fuel switch and clean them out also.

What oil do you use. I was useing Castrol GPS (I don`t know if they are selling it over at U.S). And it was not good, bike used the oli fast...
I know some guys who have had the same problem as me, with the same oli. I have even heard that some guys have had problems with cluts when they have used GPS. I can`t understand because the oli should be really good???

Good luck with the problem....  

I use Castrol GPS too, no problem at all. Oil consumption stays normal, it doesn't affect the clutch and the oil still performs well after 6000 km.

I think you have to look somewhere else for the problem.

One thing that I know about is a rusty tank. It's bad. I had a lot of rust in my tank. I mean there were pit holes and rust flakes all over the place. I used a Kreem kit and it took care of everything. So if you want to take the time to do it, use a Kreem kit. If you do end up using the kit let me know and i'll give you some good pointers.

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