Honda TRX250R Forums banner

1 - 20 of 20 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter #1
I just got another '87 250R after not having one since '93. :D My R has a stock engine with FMF Fatty pipe and silencer, which is leaking at the exhaust flange and where the silencer / pipe meet. :( What would be the best way to stop those leaks? Would new seals on the flange work as good as those new billet flanges? And does anyone sell those collars to seal the pipe / silencer? Any suggestions will be appreciated! Thanks! :D
 

·
Registered
Joined
·
190 Posts
i personally like the billet flanges best but if ya gonna stay with the stocker. i'd suggest sliding a hi-temp o-ring over the flang, applying some hi-temp silocone to the flange and header tube and re-installing the exhaust. once in place, the hi-temp o-ring should slide itself agaianst the header tube and seal off. you can also apply the silocone to the rear joint aswell as slipping a short section of hi-temp hose over the joint. hope this helps. B)
 

·
Registered
Joined
·
692 Posts
^ That is what i have always done for a leaky exhaust. Even with a billet flange i have seen it leak as much as the stocker when the o-ring wears out.
 

·
Registered
Joined
·
45 Posts
Hi mike,

This is what you need to buy.

http://www.permatex.com/images/DisplayImag...hotos/81878.jpg

Permatex® Ultra Copper® Maximum Temperature RTV Silicone Gasket Maker

everytime I play with exhaust part this is what I use. It's Cheap the tube tka e alot of time to dry out and it works everytime

Good Luck



Btw Bill I could not use the tag to post my picture for some reason ??
 

·
Registered
Joined
·
187 Posts
Sounds good, we are all here to help


What about a leak where the pipe and cylinder meet? is this stuff safe for all the heat up there? I Just bought a 86 last month, havent taken the pipe off yet to see what kinda flange is in there or anything yet. hopefully i can get to it this weekend. :rolleyes:
 

·
Registered
Joined
·
692 Posts
What about a leak where the pipe and cylinder meet? is this stuff safe for all the heat up there? I Just bought a 86 last month, havent taken the pipe off yet to see what kinda flange is in there or anything yet. hopefully i can get to it this weekend. :rolleyes:
The pipe never "Meets" the cylinder, there should be an exhaust flange in between. IT will work on both, but between the exhaust flange and the cylinder there should be a gasket.
 

·
Registered
Joined
·
187 Posts
ya thats what i meant, guess i should have worded it a little better lol.

Thanks, i probably just need a new gasket for it then, wheres the best place to pick that up at? Ill swing by the local honda shop today if i have time and see, they usually stock a ton of oem parts.
 

·
Registered
Joined
·
3,565 Posts
red RTV
"high temp" sealant made by permatex is the best !
let it set up for 24 hours do a heat & cool down ..... it last a long time
 

·
Registered
Joined
·
1,058 Posts
New exhaust springs might help too. I have the same setup...stock cylinder w/ FMF exhaust. I used high temp silicone and new 90mm Moose Racing exhaust springs.
 

·
Super Moderator
Joined
·
4,273 Posts
New exhaust springs might help too. I have the same setup...stock cylinder w/ FMF exhaust. I used high temp silicone and new 90mm Moose Racing exhaust springs.
Sealing the pipe up at that flange is very important as well.
Sealing does several things, for one, it could keep you from sucking raw air back into the cylinder & seizing the piston.
If your the type rider that likes to run the carb jetting on the lean side while trying to pull as much power out of the engine as it will produce, that leaky joint will kill the engine quicker than a cat can lick its tail. Resaon it will, the returning wave through the pipe can pull the air in through the leaking spot.

Bill,
Since you have BVC Racing, might be a good idea to stock the Three Bond products. Its a good sealer compound for most anywhere a gasket has to go & + I'm going to be recomending it to anybody I deal with, may as well have an outlet where anybody here can get it.
Neil
 

·
Registered
Joined
·
190 Posts
Bill,
Since you have BVC Racing, might be a good idea to stock the Three Bond products. Its a good sealer compound for most anywhere a gasket has to go & + I'm going to be recomending it to anybody I deal with, may as well have an outlet where anybody here can get it.
Neil
HERE! HERE! i hear that. be nice for ya to carry it. that stuff is great. one cant ever keep too much of it on hand. :)
 

·
Registered
Joined
·
50 Posts
I put one of those billet double o-ringed flanges with an FMF pipe. Everything was bought new at the same time. I have that bike for two years and it never leaked. I didn't have to use any gasket maker. Guess I was lucky.
 

·
Registered
Joined
·
388 Posts
Sealing the pipe up at that flange is very important as well.
Sealing does several things, for one, it could keep you from sucking raw air back into the cylinder & seizing the piston.
If your the type rider that likes to run the carb jetting on the lean side while trying to pull as much power out of the engine as it will produce, that leaky joint will kill the engine quicker than a cat can lick its tail. Resaon it will, the returning wave through the pipe can pull the air in through the leaking spot.
So you are saying that a leaky O-Ring/lean carb will cause the pipe to push away from the flange (likely when revving), therefore bringing air back into the cylinder when the pipe bounces back?

Teddy
 

·
Registered
Joined
·
42 Posts
i think it might be a fmf problem. i have their SST and as long as i had it i dont think i have ever completely stopped the leak. i have probably gone through a couple tubes total trying to fix the leak. the siliconge stops working after a few hours, its just a really sloppy fit.
 

·
Registered
Joined
·
536 Posts
i think it might be a fmf problem. i have their SST and as long as i had it i dont think i have ever completely stopped the leak. i have probably gone through a couple tubes total trying to fix the leak. the siliconge stops working after a few hours, its just a really sloppy fit.
How long did you let it set up for? You should at least leave it over night before running your R again.
 

·
Super Moderator
Joined
·
4,273 Posts
So you are saying that a leaky O-Ring/lean carb will cause the pipe to push away from the flange (likely when revving), therefore bringing air back into the cylinder when the pipe bounces back?

Teddy
If the pipe is pushing away from the cylinder when you rev the engine then you have a problem with the springs that hold the pipe in place.
For a two stroke pipe to work correctly it has to have some movement, not locked completely down tight. Thats why its so hard to maintain a seal anywhere the pipe has a connecter joint.

If your pipe is pushing away from the cylinder, yes you could at times suck raw air back into the pipe just from it doing that.

A two stroke engines tuned pipe is a very complicated item in how it functions & the dutys it performs.
With each rotation of the crank & cycle of the piston there are a bunch of things happening inside a pipe.
You have a pressure wave then a suction wave then a pushing pressure wave that pushes anything that was sucked out back up into the cylinder.
All this action inside the pipe is happening with in the time the piston movement uncovers the exhaust port opening untill the time it covers it back up.
Now, think about all that action happening from 0 to 10,000 rpms :eek:
Neil
 
1 - 20 of 20 Posts
Top