Cr250 bad leaky exhaust

[xs850triple]

So Ive always been a 4 stroke guy, but dang am I glad I got this bike.. I love 2 strokes now!, anyways, I feel like they have inferior exhaust as its just held on by springs instead of being bolted on like my 4 bangers

Since I've gotten the bike the whole front of the engine is just covered in oily blackness, when I start the bike cold it'll have big puffs of smoke come out where the header meets the cylinder, but goes away, after each ride I have oil sprayed on my rear spring where the header meets the silencer, big black blobs on the swingarm underneath, and where the header meets the cylinder, it is covered black and will drip a big black puddles of dispair under the bike that gets about 4inches in diameter, I know its nothing major, just sick of cleaning, tried to see if the pipe wasn't set on right but nothings changing

I really wanna fix this so I can have a clean bike.. I ran really rich through my first couple gallons of fuel, because, well its so weird to me to have no oil up top and I was afraid of seizing so I added a little extra oil to my gas.. haha bad idea, I was blowing huge blue clouds and fouled my plug before I got through 3 gallons haha

Actually if I add to much oil to the gas, is that considered running rich, or is that a new terminology.. sorry for my noobyness

[Keith72]

You can replace the o-rings between the pipe and the cylinder. That will help there. You can also use some high temp rtv silicone between the pipe and silencer. Thats what I did on mine. No more drippy drippy. You will also want to repack your silencer. Its probably soaked. You can run oil ratios from 50:1 to 28:1. Most run 32:1. I personally run 50:1. 

 

What year is your 250? Any mods? What jetting is in the carb? Give as many details as possible to get the best help.

[xs850triple]

K ill probably get some rings ordered, I haven't dove to deep into my carb as its run great since I got it, its got a wiseco piston, which probably means higher compression and probably bored out some, the carb has had work, either bored out or ported? Didn't know you could do that, and the intake has been port and polished, and its got some fancy reeds in there (also new to me) oh and its an 88

It rides great, itll pull power wheelies through 3rd gear, just makes a mess lol

[shrubitup]

Also get new springs to increase tension between pipe and cylinder. See if you can buy a TM Designs No Leak exhaust collar. Eliminates leak point there. 

 

Lean out your carburetor per these instructions. 

 

https://www.thumpertalk.com/topic/347305-is-your-two-stroke-running-rich-read-here/

[hardhitwarrior]

forget about the  new orings. its still gonna leak there with new ones sooner or later. could be that your  inner diameter of the exhaust outlet is grooved from the orings from vibrations already. just run the old ones( hopefully they are not tarnished) and put HI TEMP RTV.

Edited November 5, 2013 by hardhitwarrior

[ScootMcGoot]

Just order a new exhaust header gasket.  If I were you I would get several of them.  They don't last that long.  Also there is supposed to be a rubber piece between the expansion chamber and the silencer that prevents the dripping on the swingarm area.  Another thing you can do while you have the pipe off is to burn out all the carbon that is in the expansion chamber.  This can be done simply with a propane torch and directing the flame inside of the expansion chamber.  Once the carbon starts to burn it will keep going for a while and will not require a flame.  The same thing should be done to your silencer core when you re-pack your silencer.

 

I believe the manual for the CR250's says 32:1 however I got a carb from JD Jetting and they recommend 40:1.  To speak a bit about lean vs rich 32:1 would be a leaner ratio than 40:1 because with 32:1 you have 32 parts gasoline to one part oil vs 40 parts gasoline to one part oil.  The more oil you add the leaner the mixture is. 

[shrubitup]

forget about the new orings. its still gonna leak there with new ones sooner or later. could be that your inner diameter of the exhaust outlet is grooved from the orings from vibrations already. just run the old ones( hopefully they are not tarnished) and put HI TEMP RTV.

Right cuz o rings don't wear out much....

[hardhitwarrior]

Right cuz o rings don't wear out much....

 

 

yes they do wear out much. in fact, in just a couple of hours, youll begin to see ripples of oil anyways. its the orings but its also the groove that the orings weared out inside the outlet of the exhaust manifold. the best is to smear as thick as possible of that RTV. i havent leaked my CR with 55 hours on it straight.

[xs850triple]

Cool, well I picked up some DTV yesterday, ill put it on today and go ride tomorow and see how it dies ?

[shrubitup]

yes they do wear out much. in fact, in just a couple of hours, youll begin to see ripples of oil anyways. its the orings but its also the groove that the orings weared out inside the outlet of the exhaust manifold. the best is to smear as thick as possible of that RTV. i havent leaked my CR with 55 hours on it straight.

The RTV is a good idea but with fresh O rings there's less splooge to try and contain. 

 

If one's bike is splooging it is easier to clean up silencers and rear fenders instead of fronts of engines/skid plates/junction between pipe and silencers. 

 

Ultimately their jetting is primary cause of spooge. 

 

https://www.thumpertalk.com/topic/347305-is-your-two-stroke-running-rich-read-here/

[QueasyRider]

Is the Fatty MX a decent pipe?

The '01 CR250R I picked up has a Fatty MX and a Powercore II on it.

I'm pretty sure the bike is on stock jetting, but I'm really not sure.

 

The front of the engine has a good bit of spooge, and so does the silencer around where the allen heads are to remove the end cap.

The end cap actually rattles because someone stripped out the allen heads.

 

Haven't rode the bike yet but will this weekend and see how it does.

I would like to get a JD Jetting kit and a stock expansion chamber.

Is the OEM exhaust hard to find for these bikes - I mean, should I just keep the Fatty and Jet accordingly/Go for a Gnarly pipe?

I know for sure I'm going to have to repack and clean the exhaust as well as drill out the old allens on the silencer because they're stripped.

[CR250_182]

Since I've gotten the bike the whole front of the engine is just covered in oily blackness, when I start the bike cold it'll have big puffs of smoke come out where the header meets the cylinder, but goes away, after each ride I have oil sprayed on my rear spring where the header meets the silencer, big black blobs on the swingarm underneath, and where the header meets the cylinder, it is covered black and will drip a big black puddles of dispair under the bike that gets about 4inches in diameter, I know its nothing major, just sick of cleaning, tried to see if the pipe wasn't set on right but nothings changing

Same happened with me, someone on here suggested to me that you get 4 or so inches of the proper sized car radiator hose and put that where the pipe and silencer connect, worked for me.