As long as it's just the smaller stuff, you should come out fine. It doesn't sound like it was anything to damaging (rods, block, pistons, head, etc.). If you need help, PM me.

 

Hi, so I'm revisiting an old problem. Couldn't post anything on the form cause for the last couple of months for some strange reason I couldn't log on to the forum but anyway...
So this is how things panned out. It turned out that the main problem with my bike was that the valve clearances were way out. After they were set the bike runs much better and refs up through the whole range. The only thing is that it has a bit of a miss-fire at low refs(below about 4000-5000rpm) and the fuel consumption is a bit steep(about 124 miles(200km) on a tank and then I never drive faster then about 75mph.Its even worse when I open up...).
After playing around and removing the plug leads I discovered that the problem is on the no4 cylinder. The mechanic convinced me to replace the coil(which I new wasn't the problem) and the sparkplugs and he balanced the carbs and it still didn't solve anything. Eventually after doing a compression test (which he should have done in the first place). We found that one of the valves are leaking on the no4 cylinder. He said that I shouldn't worry and drive it for a while. It should where in by itself and seat. Now after about 1000km later and paying him a lot of money it still has the missing problem and fuel consumption though at higher ref it seems to have a lot of power so I can live with the miss-fire but not the consumption (My other friend gets 300km on a tank on his 95 blade and he doesn't drive slowly – mine is a 98')
So this is my questions:
Can a leaky valve cause these symptoms?
Is there a easy fix like a additive I can add to the gas to seal it(assuming it's not burned) or will I have to remove the cylinder head?
PS. This mac really messed things up on the bike so now I'm just going to do everything myself (interesting how much damage U can do with a hammer and I had it back in the shop 4 times!)

 

The mechanic you went to is a moron and he should trade in his tool box for a spatula at McDonalds. To start, I would walk right into wherever he works and question his credentials, and also ask for a refund on some of the things you paid for, because they threw parts at the problem without doin the most basic of diagnostics, which is irresponsible and sloppy. A compression test is always where you start, especially when an engine is way out and has valve issues. Your mechanic is dead wrong about the leaking valve, you should NOT ride the bike, these problems do not just work themselves out. What has most likely occured is heavy carbon buildup on the seating surface of the valve that is preventing it from closing all the wa, and that buildup is about as tough as cement, so it will not just burn off or wear off. This will kill your power, and make the engine run like crap. It will also kill your MPGs because you are over throttling the bike to have the three strong cylinders carry the fourth and make you move in a decent fashion. So, here is what you have to do. To start, if you can, pull the carbs and shine a light right down into the intake runners. You will be able to see all the of the intake valves and you should be looking at the tops of the valves for any buildup. You should take a picture of each cylinder, and look closely at the #4 to see if you can actually see the buildup that is keeping the valves open (if its the intake valve). I want you to do this so that you can see the difference and maybe see the problem and what happens after you do what I try. Now, ideally, you should pull the head, but before you do that buy a bottle of Chevron with Techron Fuel system cleaner. Add more than the recommended amount (maybe 3/4 of a bottle) to a full tank of gas and rock the bike to thoroughly mix the fuel and additive, do this as long as you need to until you feel like everything is really mixed together. Now, let the bike idle until fully warmed. Then you need to go for a ride, and you need to take it slow. Do not go above 5K if you can, just take it slow and let the additive do its job. I wouldn't tell you to use the stuff if I didn't KNOW that it works extremely well. The Chevron will clean your carb and remove the the carbon from your valves. You should notice a steadier idle and smoother throttle IF your valve is not burned. The next step after running the tank to empty is to fill it again and use the Chevron again, but this time in the prescribed amount. BUT, before you start the bike again, and this is IMPORTANT, you need to check all of the valve clearances. Why? Because since the valves may not have been fully seated, the adjustments your incompetant mechanic made are no longer any good, so you need to check them all again, and especially the #4 cylinder. If things are looking good, and you feel that bike is running better than take it out again and see what the performance is like. If your still having isues then I hate to say it but you will need to pull the head. If the valve is cooked then it must be replaced. Try what I have said and remember to be patient and not push the bike hard during the first tank full. It sucks that you were unable to get onto this site cause I think we could have all saved you some aggravation. Your mechanic has lied to you to avoid owning up to his incompetance and having to pay for his mistake, what blows me away is he told you to keep riding, that is truly unbelievable. Obviously do not use that shop anymore. If you can, get a manual and start doing the upkeep by yourself or with a friend who is mechaincially inclined, at least you know it will be done responsibly and with your best interests in mind. Good luck and please update me once you've run a tank full of gas through her. Also, if you find that things are imporving and the idle is smoother and the hesitation is going away, please pull the carbs again and look at what the valves look like. You might get lucky with the Chevron so have hope.

 

No your right about the mac and I already realized this long ago but since I had already payed him I had to take the bike back a couple of times to see if I could at least try and see if he could fix the problem but now I think I'm just gonna cut my losses...
I'm fairly ok when it comes to servicing engines and cleaning carbs and I've even replaced clutch plates but I get a bit nerves when it come to removing the head on a motorcycle and mess with the valves cause if U do something wrong there U could end up with a valve breaking a piston. I'll very soon have to check the valve clearances on my F3 as well so It's probably a good idea to learn now...
Your idea sound good but I only have one problem. I'm from South Africa and Chevron with Techron isn't sold here. Any other brand U can suggest? (else I'll just go ask my local spares shop to recommend something good for cleaning carbon from valves?
If it comes to removing the head, I'll need a couple of pointers and can U do it in the bike or do U have to drop the engine?