CMB 101RS keeps blowing pipe off coupler

[Kip Tullos]

My 101RS is running in tip top form with one persistant prob - the pipe keeps slipping out of coupler. Keep in mind that I have 3 heavy duty pipe clamps bolted on and using a fresh silicone coupler. When I launch it feels very secure but a few mins in the engine changes tone and you know the rest..

Any advice on the most bullet proof way to stop this? I guess I could weld it up - the length seems perfect - thanks for any/all help - Kip

 

[SayMikey]

My 101RS is running in tip top form with one persistant prob - the pipe keeps slipping out of coupler. Keep in mind that I have 3 heavy duty pipe clamps bolted on and using a fresh silicone coupler. When I launch it feels very secure but a few mins in the engine changes tone and you know the rest..

Any advice on the most bullet proof way to stop this? I guess I could weld it up - the length seems perfect - thanks for any/all help - Kip

How are you supporting it in the rear?

 

[Daniel's Racing]

I have had that problem when using the CMB headers and believe it is because the header diameter is so much bigger than the pipe is and it has one end opened up and stretched over the big header and it seems it blows oil and pressure up under the coupling between it and the pipe lubing it up inside and it just slides out. I think that turning the diameter off the header for the coupling would help tremendously. A thick white teflon coupler sometimes will stop the blowout still best to reduce header diameter to closer to that of the pipe as it can be a bear to get even sloppy hot teflon over the huge CMB header if that what you have. ???? POnce out of frustration with one screwed a doggone stud screw of all things right through the coupler and inton the aluminum pipe. You know it is still in there and holding like a champ.

You can try to capture it with the rear clamp. A Adel rubber lined clamp up on the body or stinger and securely mounted will limit or at least help keep it in but it really should be held in by the coupler or it will always be trying to wear into it's mounting and risk it moving again in the middle of a heat.

 

[Andy Greene]

My 101RS is running in tip top form with one persistant prob - the pipe keeps slipping out of coupler. Keep in mind that I have 3 heavy duty pipe clamps bolted on and using a fresh silicone coupler. When I launch it feels very secure but a few mins in the engine changes tone and you know the rest..

Any advice on the most bullet proof way to stop this? I guess I could weld it up - the length seems perfect - thanks for any/all help - Kip

How are you supporting it in the rear?

That would be the first thing I checked-

You should burn a coupler before blowing the pipe off IMHO

After that , contact Tom Foley here on this board.

He makes a sweet adaptor to your header that will eliminate the gap between the pipe and header AND you will be to adjust the length easily.

Andy

 

[Kip Tullos]

I have it supported with the standard pipe clamp set-up (speedmaster) tightened as much as possible. the header is bored out to where the pipe slides inside the header. And then clamped TIGHT with coupler over. I like the idea of putting the screw through it - may try that one - you can see the clamps in pic...

 

[BigChuck]

Ok

First reverse the eyelet so it slides down the stinger until it can go not further.

Second in I am seeing correctly, you have a leading pipe. Radius the outside edge of the header so it makes a snugg fit to the pipe. This will stop the leaks. Work at it a dry fit before you put the coulper on. I run the samething and ran all day today.

 

[Kip Tullos]

Yeah I have the eylet all the way on when I run (not so in pic) and that helps - What I see in your pic is the coupler is all the way down to base of the header - thats what I need to try tomorrow. It gives me an appreciation for the the power, heat & energy these little monsters generate!!!

 

[Daniel's Racing]

Did the telescopic deal to the Razor and it did keep more of the heat in the pipe and from softening the teflon. These couplers last the life of the header and pipe.

 

[Kip Tullos]

Did the telescopic deal to the Razor and it did keep more of the heat in the pipe and from softening the teflon. These couplers last the life of the header and pipe.

What a clean set up! Good looking...

 

[HendricX]

Would be even better if right clamps are used.

They have a 'spring-type' function , so not eating up the Teflon as 'hose-clamps' do ,

and keeping constant pressure .. so it's absolutely leak-free.

The trick is to choose clamp-diameter 2mm_5/64" smaller as needed.



But I don't understand .. normally a CMB manifold slides INTO the CMB exhaust.

Using a CMB 1"/25mm manifold on a 7/8" exhaust is you own doing ... buy the CMB 7/8"/22mm manifold.

 

[dwilfong]

I have bin using the Octura orange coupler and it will weld its self to the pipe and header. I use no clamps at all. It will burn thew over time but it will never move.

It is a true hose with reinforcement in it. John Otto has some new coupler material that is similar but the reinforcement is much better. some kind of special stuff .

I think kevlar.

David

 

[TimothyJones]

Kip

You need to move the support back to the beginning of the taper, where the stinger starts.

That will keep the pipe from sliding out. Right now you have approx a 1" where it can slide back.

tim

 

[seaducerpete]

david where do you buy the octura orange coupler

 

[robertpickard]

Pete you can get that coupler from John Otto i use the same coupler as David, go to Technologieshobbies

 

[seaducerpete]

Cool thanks

 

[dwilfong]

John showed me the new coupler at the last race. I still have some of the Octura left to use up. I get Octura at the local hobby shop. But will get the new stuff from John when my supply runs out.

Hose with the cording in it will not stretch when it gets hot no clamps needed.

David

 

[Kip Tullos]

John showed me the new coupler at the last race. I still have some of the Octura left to use up. I get Octura at the local hobby shop. But will get the new stuff from John when my supply runs out.

Hose with the cording in it will not stretch when it gets hot no clamps needed.

David

Thanks - Sounds good - I sent him a msg and will load up! Already a big fan of his fuel...

 

[dr gary turner]

John showed me the new coupler at the last race. I still have some of the Octura left to use up. I get Octura at the local hobby shop. But will get the new stuff from John when my supply runs out.

Hose with the cording in it will not stretch when it gets hot no clamps needed.

David

Thanks - Sounds good - I sent him a msg and will load up! Already a big fan of his fuel...

Kip it is the way you have the pipe mounted. Bring it to the house and I can show you the problem. To hard to explain. Doc

 

[Daniel's Racing]

Yep if it were supported differently it might help but pipe should really stay in even if the pipe mount fell off.

 

[Kip Tullos]

The picture is to show coupler clamps guys - The pipe is simply laying in the boat in that pic. I mount the eyelet all the way onto the stinger when running..