Exhaust gasket loosening bolts....

Petrolheadz100

Well-Known Member
Messages
243
Noticed my screws keep getting loose on the exhaust because the stock gasket that comes with the tuned pipe isnt sealing, vibration breaks bolts loose. Any suggestions on using the DDM graphite gaskets or silicone red rtv gasket maker?
 

Thwmathue

Well-Known Member
Messages
55
The best recommendation I can give is very so often give the exhaust bolts a grunt. Locktite won't work as it gets to hot. Just bring it in and check the bolts
 

Petrolheadz100

Well-Known Member
Messages
243
isn't it better to use some silicone RTV instead of the gaskets because the gaskets seem to burn down overtime and calls the bolts to get loose? Anyone usimg rtv on these eshausts hat can share experience....
 

sunoco

Well-Known Member
Messages
170
silicone sealant is pretty much no account. useless. but, thats just my opinion. As much as i dislike the stuff, red lok-tite will hold. Best thing to do-- agan, my opinion- buy up the graphite coated stainless steel exhaust gaskets & exhaust studs with included bolts from DDM. About one drop of red lok-tite applied with a toothpick 1/2 way into the holes where the exhaust studs are threaded into the head. A faster, cheaper way?? go to a good hardware store- ace hardware comes to mind-- Ask the store person where the metric studs are-- get the nuts there also-- buy 4. seat the first 2, then lightly jam the 2nd 2 onto the first nuts.-- problem over.
 

sunoco

Well-Known Member
Messages
170
all RTV means -- Ready To Vulcanize. a selling point.
 

Petrolheadz100

Well-Known Member
Messages
243
My friend uses it on his airplanes exhaust says it works great , i was looking into those from DDM graphite gaskets. Will those work by themselves without the thought of the bolts coming loose from vibration?
 

Painlesstom

Member
Messages
8
Location
GA
I just got back into trucks and picked up a Rampage MT V3. New to these, but not to 2 strokes in the RC world. Have been hanging out on the aviation side for many years flying giant scale gas planes, largest is 40% 170cc. All the serious builders ditch muffler gaskets and use red RTV with red loctite on the bolts. Let that cure for 24 hours and it will hold up for a good 200 flights in my experience. I have a dozen planes I've built and fly regularly so I trust the method. Just put a tuned pipe on my MT so time will tell if it will work on the ground too.
 

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imaudi5000

Member
Messages
24
Any other suggestions? I'm having the same issue with my catbox muffler, it vibrates loose every time I drive it. I tried blue and red loctite but they don't hold up. Is it a screw issue or a support issue? Does it need something holding it up like a tuned pipe? Do the tuned pipes still shake loose?
 

Painlesstom

Member
Messages
8
Location
GA
Use red rtv instead of the gasket, and red loctite on the screws. Tighten and let cure for 24 hours. My tuned pipe cracked after 3 tanks of fuel but the screws won't come loose until I take them out.

If red RTV and red Loctite works on my DLE170 mufflers, it will work on this 30cc fine too. Have been flying it for a year now, 39 flights, 5.2 hours run time, and nothing has come loose yet. lol
 

imaudi5000

Member
Messages
24
Yea I 'rebuilt' the catbox a few weeks ago and did red loctite on the screws. it has two screws that are only accessible from inside the box, ugh. The gaskets and x shaped flange thing looked good so I cleaned those up and put them back on like normal. I did use the gray permatex gasket make (the stuff good for gas/oil contact) to seal up the lid and box. I let everything cure for a week before I ran the car again. lid is sealed nicely but the whole box started to come loose after one short run, like half a tank maybe. I guess I'll try more loctite on the screws and some gasket maker on all the flange surfaces and see if that helps at all.
Next step is a better exhaust with external screws I guess lol.
 

Painlesstom

Member
Messages
8
Location
GA
Make sure the threads in the head and the screws are clean and dry, then be generous with the red loctite. Grey rtv isn't for high temp, that's why you use the red rtv.
 

imaudi5000

Member
Messages
24
Ok, but I thought the red wasn't good for gasoline contact? Or is there not enough unburnt gas in the exhaust fumes to degrade the rtv?
 

Painlesstom

Member
Messages
8
Location
GA
We've been using it in the gas airplane side of the hobby for many many years, drag racers have been using it for header gasket material for even longer. Cured RTV is impervious to fuel, and the high temp stuff was made for this job. I don't know the chemistry behind it, I'm just telling you it's been used for too many years with great success to argue with the results. ;)
 

Painlesstom

Member
Messages
8
Location
GA
Yeah, long term direct contact with fuel probably wouldn't work well. My statement about it being impervious to fuel was meant in context with exhaust, not in general.
 

Jack Austin

New Member
Messages
1
Noticed my screws keep getting loose on the exhaust because the stock gasket that comes with the tuned pipe isnt sealing, vibration breaks bolts loose. Any suggestions on using the DDM graphite gaskets or silicone red rtv gasket maker?
Im running the stock exhaust with the steel muffler and I tack welded the head of the bolts to the muffler to keep them from backing out. When I’m ready to take it off I’ll use a Dremel to cut the spot welds so the bolts can be removed.
 

V8srfun

Active Member
Messages
29
I found that if you get a new gasket and tighten it up then check it every ten minutes or so of running for the first couple tanks of fuel the gasket will stop crushing and the bolts will stop getting loose. The key is to keep it tight so the gasket does not start to burn. If it starts to burn it will never stay tight.
 

biggo

Well-Known Member
Messages
71
Location
USA, Baltimore, MD
Just make sure the screw holes are clean. Use blue lactate, torque bolts and let cure. I did have countless issues with the stock exhaust. Zero problems since replacing it.
 

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