250R leaking fuel issues!! Help!!!

[lisnup65]

I pulled my 85R out last night for the 1st time in months. I kicked it over and she started right away. I noticed that the exhaust at the cylinder was leaking worse than normal.(How do you get a good leak proof seal here?)
I let it warm and took her for a little ride. I pulled her back into the garage and noticed that the area below the exhaust port was severly saturated with a oil/runny liquid mess.(I mean way more than normal). As I was inspecting I noticed that on the floor under the machine a puddle was forming. I inspected the liquid that made the puddle up and it appears to be gas.
I then turned the fuel valve off and inspected the carb to find that the carb was not leaking. All drain hoses were bone dry!!!!!
I grabbed a flash light and started to look into it a bit more. It appears that the gas puddle cam from raw fuel coming out the Exhaust port and that was why I could see such a build up on the area under it.
What is it that would cause this? Maybe a reed issue? The funny thing is that the machine ran fine and did not appear to be flooding itself out. I could let it idle of chop the throttle and she runs great. I did notice that when I chop the throttle, I get oil/fuel splatters up to 4 feets away from the machine. Thats how bad the leak got and how much gas/oil is coming out of the exhaust port.

Thanks for any insight,
Dave

[TimSr]

My first guess is that you are leaking through the float needle and seat, and for some reason it dumped (or siphoned) a bunch of gas into the cylinder while it was sitting, intsead of overflowing. The overflow may have been plugged, or it may not have been sitting level, or it may have gotten a little siphon action going when it was first parked lat time you rode it. When you started it, is probably when it decided to start blowing it out. It was probably oozing and running the whole time you had it running, but your cylinder was cleared by the time it warmed up. Always shut your gas off when its parked, and dont trust the float needle.

[x.system]

To get a good seal at the exhaust side first make sure you have the expansion ring on the exhaust flange. I use red permatex to seal the area, coat both the flange and the inside of the pipe and let it set up for a few minutes then install it. I usually let mine dry about 24 hours before I fire it up. You will get better performance by making sure your exhaust is sealed all the way back. I also use the permatex on the second joint with a piece of radiator hose with two clamps. This method has worked for me for many years. Another old trick is to put some permatex on the exhaust springs, this will keep them from vibrating and breaking.

[lisnup65]

My first guess is that you are leaking through the float needle and seat, and for some reason it dumped (or siphoned) a bunch of gas into the cylinder while it was sitting, intsead of overflowing. The overflow may have been plugged, or it may not have been sitting level, or it may have gotten a little siphon action going when it was first parked lat time you rode it. When you started it, is probably when it decided to start blowing it out. It was probably oozing and running the whole time you had it running, but your cylinder was cleared by the time it warmed up. Always shut your gas off when its parked, and dont trust the float needle.

I thought the same thing, but the overflow tube is not clogged as I am able to blow into the carb. I restarted the machine this morning after sitting overnight with the fuel off and I am still getting the same thing. The motor is soaked under the exhaust port, the motor protector plate has a lake on it, and the cardboard under the machine has absorbed a 17" diameter circle of fuel and black sludge from the exhaust.
I will pull the carb off after work today and give it a good going through. I rebuilt this carb around 1.5 years ago when I picked the machine up. I only have around 5 hours total ride time on it.

Any suggestions how to seal the exhaust up better at the exhaust port? I have cleaned the area up in the past and used high temp silicone as a gasket maker, but it only last a few hours at best. I have also replaced the springs to make sure they were holding the expansion chamber tight enough.

Dave

[lisnup65]

. I also use the permatex on the second joint with a piece of radiator hose with two clamps. This method has worked for me for many years. Another old trick is to put some permatex on the exhaust springs, this will keep them from vibrating and breaking.

Thanks for the advice. I was just thinking of a way to get a better seal at the other joint areas. Those little factory style rubbers with the little springs to seal them always seem to leak severely.

[hrc85250r]

Thanks for the advice. I was just thinking of a way to get a better seal at the other joint areas. Those little factory style rubbers with the little springs to seal them always seem to leak severely.


or you can get a billet flange with o-rings for 45$ from ebay or ESR250.com

[85 250sx]

do those billet flanges seal better than tha stock ones and do they fit the same? because it think i remember hereing that someone had to machine theres down to fit? and what are the advantages to a billet one rather than a stock one?