'88 GSX 600 with oil in the gas.

[mrkaylor]

I really meant gas in the oil.. sorry for the incorrect heading.

I just got this bike and I was told that when I bought the bike that it would leak gas after it ran for a few minutes. Sure enough after it runs for a few minutes gas pours out of the airbox. I took the airbox off and discovered that it was actually pouring a gas/oil mixture out of the crankcase cover breather at the top of the engine. So I drained the oil and it appeared to be about half oil and half gas. I thought it might be a float causing gas to overflow into the engine so I took the carbs off to examine. They were very clean but I found two needle/float valves that didn't entirely close. (Tested by turning the carbs upside down and blowing into the gas line that comes from the gas tank). So I ordered two new float valves. I'm also going to run a compression test tomorrow to hopefully rule out any compression problems.

If anyone has any other ideas or thoughts I'l like to hear them. I already used the search function to get the ideas to test the compression and check the floats.

Thanks for any help.
MRKaylor

[Kreylyn]

Clean and inspect the float needles, and the ports they fit into. You may just need to adjust the float settings (bend the tab) to get them to seat correctly.

Krey

[Court93kat]

Also don't forget once you are ready to start it again, put some cheapo oil in to flush the rest of the gas contaminated oil from the oil cooler as well. Then after a few minutes of the engine running drain again and refill with good oil.

[mrkaylor]

All the floats were set to about 12mm. The manual says they should be set to 13.6 - 15.6. So I set them all to about 14.6 (or as close as I could get). I adjusted them according to what Carbs 101 says: http://katriders.com/vb/showthread.php?t=63344

[bill@accent]

If the pins that hold the floats in position do not come out easily, be careful that you don't get overly aggressive with them and end up breaking a plastic float arm, as I have done.

[mrkaylor]

I tried cleaning the float needle but they still leak so I'll just have to wait for the replacements. I also had a chance to run a compression test and everything was good there all were between 145 and 155.

[bill@accent]

I tried cleaning the float needle but they still leak so I'll just have to wait for the replacements. I also had a chance to run a compression test and everything was good there all were between 145 and 155.

Thats good news. The 1988 600 project bike I bought turned out to have two corroded cylinders. Had to replace the cylinder and four pistions.

[mrkaylor]

Well I replaced the float needles and adjusted the floats but now when I start it, it revs to 6k and pretty much stays there. I made sure the idle screw was all the way out and that the throttle cable wasn't holding the throttle open.

I just adjusted the throttle so the valves/butterflies(?) are closed. Also I noticed that the pilot screws are three full turns out, is this ok? Will three turns out cause my idle problem? I'll retry it with the valves closed all the way but they didn't appear to be very open to begin with.

Thanks for all the help so far everyone.
Michael

[mrkaylor]

Well I'm not entirely sure why it was revving so high. Most likely I had the carbs open to much. When I had them off I reset them according to the carbs 101 bench sync section. I also set the valves, which most of them were to set to open. And I did a proper carb sync once I had it at a reasonable idle. Anyway I can idle it at 1k now if I want and the needle barely fluctuates. The throttle had been hanging at 2k after a rev before also, but not anymore. I haven't had a chance to get it on the highway yet, but I'm pretty sure it's going to run just fine since I had ridden the bike when the previous owner had it, and I knew exactly what he had done to it in the first place. I did notice that the main jets were only 118's when I had the carbs off, which I thought was odd. I would have thought that since the bike had after market exhaust it would have had bigger mains, but whatever.

I'd just like to thank everyone for their help before.
Thanks
Michael

[ITS_NOT_A_KNIFE]

stock jetting on a 750 is 112.5 if i remember right

[Kreylyn]

88 600 stock sized jets are...

• Type BST31SS
• Main jets 1 and 4 137.5
• Main jets 2 and 3 135

All pre 750s are

• US, cylinder no. 3 110
• All others 105

Check out the wiki for more info...

http://katriders.com/wiki/index.php5?title=Carburetor_Settings_and_Specifications

Krey