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Gas in the oil, won't go into gear: valve problem?

Posted: Sat Mar 01, 2008 5:56 pm
by MrMcBa$tard
I just bought my first bike. It's a new bike (as in not just new to me, but only 120 miles on the odometer) that hasn't even been broken in, yet.

The guy I bought it from said it had been sitting for a while, so decided to do some maintenance before I took it out for my/its first ride.

I put some fuel stabilizer in the gas, cleaned the spark plugs, charged the battery, and changed the oil. Everything seemed normal except for the oil. It was suspiciously dark for having only been used for at most 120 miles. It was also really thin and smelled a little like gasoline. There were also tiny metal shavings in the oil and filter. And finally, after I shut the bike off, some grey smoke came out of one of the exhaust pipes.

I've read that metal shavings are to be expected on brand new vehicles, as the pistons scrape grooves into the cylinders. But should the oil be dark brown after just over 100 miles? And is it normal for there to be gas in the oil (maybe something to do with the cylindars not being fully sealed, yet?)? I'm pretty sure this isn't normal, but I thought I'd better ask someone more experienced.

So, anyway, after I changed the oil, I ran it for a little bit, then I was going to take it for my first spin around the block on it. I thought it was a bit odd that the engine wouldn't keep idling unless I kept the choke at least halfway open. Is this something to do with it being new as well?

So, I left the choke about halfway open, but, whenever I put it into gear, it would die. I don't think it was because I was releasing clutch too fast or not giving it enough gas; when I eased of the clutch, I'd give it a little throttle, and it would start to lurch forward, sputter, then die. After three tries to get it into gear, it wouldn't start anymore, and there was a weird smell to the exhaust.

My roommate, who is a little bit more mechanically inclined than I am, suggested that the problem might be with the valves not having the right timing, which he said might account for gas in the oil (because too much gas was getting into the cylinder at the wrong time, then seeping out with the oil) and smoke coming out of the one exhuaust pipes (becuase the exhaust valve wasn't fulling closing). Does this sound plausible? What are some other problems that could be causing these symptoms?

What and where should I start looking at my bike to determine the exact problem? Should I tear down the engine to look at the valves? If so, how do fix them? Am I getting in way over my head? Should I just take it to a mechanic? Any suggestions would be greatly appreciated. Thanks!

Posted: Sat Mar 01, 2008 7:05 pm
by Johnj
Did you buy this bike at a dealership, or from some guy hanging out on the corner, in the run-down part of town?

Is there a dealer close by, and did you get the warranty transfered?

Or is this the 2003 Hyosung?

Posted: Sun Mar 02, 2008 1:48 pm
by MrMcBa$tard
I bought it from the guy on the corner in the run-down part of town. There is no warranty.

Posted: Sun Mar 02, 2008 4:36 pm
by Johnj
OK is there a Hyosung dealer nearby? You need to find a shop manual for your bike. Try Googleing your model, I bet you find forums and sources of parts and such. I'd do it for you, but I'm busy making diner.

Posted: Sun Mar 02, 2008 5:21 pm
by MrMcBa$tard
I have an owners manual (most of it written in pretty humorous Engrish) and a parts list that I downloaded from the company website, and I found a nice service manual out on the interweb somewhere. But none of this literature helps me determine the cause of the symptoms my bike is experiencing. Am I on the right track with the valves? Or should I look into something else?

There is a dealer a little ways from where I live. Are you implying that I shouldn't try to fix this myself and just take it to the dealer? If your advice is "take it to a professional," is a dealer the best option? Based on my experience with cars, dealers are more expensive without having any more expertise than a regular mechanic. Is this different in the motorcycle world? Are the dealership mechanics actually worth what they'll charge?

Posted: Sun Mar 02, 2008 6:32 pm
by Johnj
I have no idea how mechanically inclined you are. Do you always have bad luck when taking things apart and putting them back together, so it works correctly? I also don't have one of those bikes to look at. Is the front carb located above the front head and the rear carb located behind the rear head? Did you check the petcock to make sure it's shutting off the fuel? I assume you drained the contaminated oil and replaced it with new oil. Has the new oil gotten contaminated with gas yet?

Posted: Sun Mar 02, 2008 8:28 pm
by MrMcBa$tard
I never expected you to fix my bike or figure out the problem for me. I am simply asking if anyone has experienced these symptoms, and what other parts of the bike I might check to determine the root of the problem.

I didn't ask for people to call into question my technical ability or the soundness of my motorcycle purchase.

I appreciate your advice to check the petcock; I will look into it. I did drain the old oil and replace it with new when I changed the oil. The new oil does not smell like gas, like the old oil did, but this is only from taking the oil cap off and sniffing at the hole. I suppose I could change the oil again and take a closer look.

The carbs are situated as you said. Is this significant?

Posted: Mon Mar 03, 2008 8:12 am
by storysunfolding
I changed my oil on the V-strom after 50 miles and it was nasty. There is lots more blowby before the rings are seated.

If there is gas getting into your oil that's very bad. It'll thin it out and mess up your motor. Gasoil was the death of the yamaha triple caused by faulty petcock diaphrams.

Posted: Mon Mar 03, 2008 8:46 am
by Johnj
MrMcBa$tard wrote: The carbs are situated as you said. Is this significant?
Well if the float on the front carb is misadjusted so it continues to fill the gas would run to the intake valve which if it was open the gas would flow into the cylinder, flow past the unseated rings and into the crankcase where it would mix with the oil.
I'd start by cleaning the carbs real good and bench test the floats to make sure they shut off the flow of gas when full.
Does the bike have a manual or a vacuum operated petcock?

Posted: Mon Mar 03, 2008 4:04 pm
by flynrider
This bike is apparently 5 yrs. old and has only done 120 miles. This means it was probably sitting idle in a garage for years and is going to have all the problems associated with improper long term storage.

The metal flecks in the oil are normal for an engine is just breaking in. Gas in the oil is not. In my experience with resurrecting garage queens (where gas in the oil is fairly normal), the usual cause was deteriorated gasoline had gummed up a float needle(s) and gasoline was able to seep from the carbs into the engine. From there it seeps past the rings and into the crankcase. The behavior of the bike when you tried to ride it also sounds like your carbs are full of gunk.

The usual fix for this is changing the oil and cleaning out the fuel system from tank to carbs.