[GirlsRideToo]

Backed my 2014 Rancher 420FM out of garage today and noticed very hot hair blowing against my upper left leg. Admit that the tank cover assembly is off because I'm still doing some cleaning.

It isn't just the pipe being hot, I can feel air "blowing". I'm just not sure where the air is leaking from.

Attached photo shows my hand where I am feeling the hot air. I do not see or feel any holes but the cover is still on.

Is it possible that the leak is coming from where the pipe attaches to the cylinder and I'm just feeling it further away. I'm stumped and don't want to start taking things apart until I can narrow down the problem.

The cylinder was rebored and valves replaced about 8 months ago. Runs fine, no backfires, no oil leaks.

 

[fishfiles]

....a smoke machine would be a good way to find a leak in the exhaust , I been wanting one for checking snorkels and now you made me think it would be good for checking the exhaust for leaks

 

[GirlsRideToo]

....a smoke machine would be a good way to find a leak in the exhaust , I been wanting one for checking snorkels and now you made me think it would be good for checking the exhaust for leaks

Don't have a smoke machine laying around and I assume my Bubble Machine won't work. LOL

Will soapy water work? IF so, is it safe to spray ti around the area where the pipe inserts into to the cylinder head??

The manual is no help and I have searched the Internet for hours and still not sure what to do.

 

[rustynut2]

Hook a vacuum up with the hose reversed (blow) to the tail pipe and then use soapy water. I like the power of dawn......

 

[fishfiles]

if you have an exhaust leak , it could only be a few things ------ it could be the copper crush washer at the head ------ if your pipe has a joint in it , which my 450 does , then it could be a sealing sleeve that goes in the joint ------- or a hole rusted in it

the vacuum cleaner with reversed flow sounds like a plan

 

[GirlsRideToo]

if you have an exhaust leak , it could only be a few things ------ it could be the copper crush washer at the head ------ if your pipe has a joint in it , which my 450 does , then it could be a sealing sleeve that goes in the joint ------- or a hole rusted in it

the vacuum cleaner with reversed flow sounds like a plan

Hook a vacuum up with the hose reversed (blow) to the tail pipe and then use soapy water. I like the power of dawn......

Thanks for the info Fish. That is what I needed to know.

Great idea Rusty. I can do that!

Will keep you posted.

 

[GirlsRideToo]

OK, got the exhaust cover off and got all the dried mud off the exhaust.

Unscrewed the two bolt at the head. They were not very tight, especially the bottom one. Manuals says torque is 9 lbf-ft But, I see that the bolts simply hold the exhaust bracket to the head and does not seem to offer any type seal, or does it?

I see some marks on the exhaust that seem to indicate depth?

I don't see a "gasket" so I assume it's inside the head?? Or is it supposed to be at the back of the bracket??

 

[fishfiles]

#1 on this print , it is a copper crush ring , when tightened it smashes the ring flat , you need to pull the pipe out the head and use a pick or screwdriver to get it out , some times
it might just fall out



https://www.partzilla.com/catalog/honda/atv/2014/trx420fm1-2ac-trx420fm1/muffler

 

[GirlsRideToo]

#1 on this print , it is a copper crush ring , when tightened it smashes the ring flat , you need to pull the pipe out the head and use a pick or screwdriver to get it out , some times
it might just fall out



https://www.partzilla.com/catalog/honda/atv/2014/trx420fm1-2ac-trx420fm1/muffler

Okay. Silly manual calls the crush washer a "gasket". I'll see if I can get the pipe out. That should be interesting... LOL
THANK YOU!

 

[fishfiles]

So , is your pipe one piece all the way back , or two pieces , one a header and the other a muffler ? Don't forget to unbolt the rear mounts of the pipe and muffler

 

[fishfiles]

Do you know that on that print up above , if you click on the part you want , it will take you to a description and interchange page , and sometimes show a pic -----and they must know about the landscape button on the cam as their pics are always right , LOL ---the pics I took today came out straight

Crush washer / Gasket
https://www.partzilla.com/product/honda/18291-MN4-920?ref=d7418995d0482f5fe847536c0f3d415e4776fb63

when you put that back together , what I do is get it evenly snug with the mounting bolts of the pipe and muffler just finger tight , start the engine and let it get hot , then tighten the exhaust flange bolts , then tighten the mounting bolts

 

[LedFTed]

if its leaking where the exhaust gasket is; those 2 bolts, with 1 being very loose, says alot. if you were to use the dawn ultra soap test, i think you could also get someone, to turn the engine over very slowly, if it has a pull rope. Key off of course, and bublles will show :wink
my 55,1st,6cyl., had a 2 piece intake/exhaust. i was warped, at the block a bit, most exhaust. i got a new gasket, put orange copper permatex form-a-gasket on both sides and snugged it up fairly good. 4-5lbs. i let it dry overnight, then tightened up to specks. that set-up lasted over 15 years. it might still last, as i sold the truck.
i agree with shadetree strongly that form a gasket, should not be used where it is in contact, with internal engine function, be it gas, water, or oil, even air/ vacuum.. i cant say i always follow those rules exact. :wink

 

[GirlsRideToo]

Do you know that on that print up above , if you click on the part you want , it will take you to a description and interchange page , and sometimes show a pic -----and they must know about the landscape button on the cam as their pics are always right , LOL ---the pics I took today came out straight

Crush washer / Gasket
https://www.partzilla.com/product/honda/18291-MN4-920?ref=d7418995d0482f5fe847536c0f3d415e4776fb63

when you put that back together , what I do is get it evenly snug with the mounting bolts of the pipe and muffler just finger tight , start the engine and let it get hot , then tighten the exhaust flange bolts , then tighten the mounting bolts

I haven't been to Partzilla in a long time. I use Rockymountainatv exclusively. But, thanks for the tip! Very helpful.

WOW, so happy to know your camera problem is resolved. Bet you're a Happy Fish Camper. Keep the pics of that monster quad coming!

Hate to be blonde, but..... I'm confused by Mounting vs Exhaust Flange Bolts in the mounting procedure you described.
My exhaust is all one piece.
I have two bolts that mount it to the head. One other bolt attaches the rear cover over the muffler. No other bolts.

 

[fishfiles]

Here is a print of your exhaust , I see your is different and pretty simple , it has a hanger , mine has bolts holding the muffler to the frame ----so it would seem after you loosen the flange bolts , then you just slide the muffler/pipe forward

 

[GirlsRideToo]

if its leaking where the exhaust gasket is; those 2 bolts, with 1 being very loose, says alot. if you were to use the dawn ultra soap test, i think you could also get someone, to turn the engine over very slowly, if it has a pull rope. Key off of course, and bublles will show :wink
snip.......

Ted, I think you're on to something. Not only was that bottom bolt looser than the top one, the gasket looked looked like it was tilted because of the difference in the looseness of the screws.
I measured the turn out of both bolts are they are equal and within specs.
I'm going to put the bolts back on and be sure they are tightened down correctly, crank it and see if I still feel the leak.
If that doesn't work, I'll move on to checking the crush washer and look for any other leaks.

Here is a print of your exhaust , I see your is different and pretty simple , it has a hanger , mine has bolts holding the muffler to the frame ----so it would seem after you loosen the flange bolts , then you just slide the muffler/pipe forward

Got it! Thanks!!!

 

[LedFTed]

if you are using the tilted gasket, ya might still feel some leak.. orange copper, is not bad to work with, after it sets up.

 

[GirlsRideToo]

I cleaned the bolts and connector really well to removed the rust and dried mud.
Remeasured the post and they are equal and within spec. They are secure.

I did NOT remove the pipe. I simply bolted the connector back on and snugged it down fairly tight.
The leak is a LOT better. I feel only a slight air leak now but that pipe is so damned hot from the moment I crank it that it's hard to get my hand very close. Is it supposed to get that hot that quickly??
Is a slight leak okay/normal?? Or should I go ahead and replace the crush washer/gasket?

 

[fishfiles]

... a leak at the exhaust pipe flange can cause valve damage ....

 

[LedFTed]

like fish said . exhaust leaks cause valve problems.

democrats are saying now, because cows leak at the exhaust ports, they should be eliminated. if they want to eliminate animals that leak methane, the worst, they should start at congress. hot gas at both ends. lols
per person, per party.

 

[LedFTed]

a lit birthday candle, may not be as hot as gas/air under pressure, when the plug fires, pressure = more heat. its an explosion. so at the exhaust, there is a lot of heat. that is how the cylinder has the power, that it does. i forget how hot it gets, 600f-1,400f i would guess. closer guess, 650f-750f. its been a while.