Sticking Valves

john charlton

john charlton

Well-known member
I have the symptoms of sticking inlet valves ,hard starting and popping etc etc . MMMO and Seafoam are both available here in the UK . Has anyone had success injecting one or the other into the running engine and which do you think works the best if at all . I would like to fix this without pulling the head . Thank you fellow "Barners "

John in a very cold Suffolk County England .
 
Kind of hard with an updraft carb. I would dump a LOT into the gas tankto not too much gas and run it. JMO
Paul in CT
 
I unstuck valves in a 27 Lincoln by adding MMO to the oil (The correct percentage is stated on the bottle.) And into the gasoline.
 
Marvel Mystery Oil has worked well for me. I always add to gas.

Use high detergent oil to. 20w-50.

Good luck.
 
Use a small spray bottle to direct MMO to carb inlet while on fast idle. I opened the vacuum wiper fitting and used a straw, but don't suck up too much and hydro lock the piston, Just short shots!
 
If using the additives don't work they can usually be freed up by just removing the side cover and working the valves manually.
 
J Franklin said:
Use a small spray bottle to direct MMO to carb inlet while on fast idle. I opened the vacuum wiper fitting and used a straw, but don't suck up too much and hydro lock the piston, Just short shots!
Click to expand...


Yep, that's what I did on my 31 - worked great.

PS- Spent my UK time in Oxfordshire. Enjoyed it all - even the warm beer (eventually LOL).

Good Luck
 
For a bad case of sticking valves where the stems are coated with old sticky fuel residue, I have removed the plugs and sprayed carb cleaner at the open valves. You have to rotate the engine to get to all the valves when they are open. Then add some MMO to the fuel to be sure they get all freed up. after some running, everything was freed up and the engine was running as it should.

This saved having to get into the engine.

Chris W.
 
CWPASADENA said:
For a bad case of sticking valves where the stems are coated with old sticky fuel residue, I have removed the plugs and sprayed carb cleaner at the open valves. You have to rotate the engine to get to all the valves when they are open. Then add some MMO to the fuel to be sure they get all freed up. after some running, everything was freed up and the engine was running as it should.
This saved having to get into the engine.
Chris W.
Click to expand...

Yep, way to go. Can also spurt some penetrating oil at the valve stem thru the plug hole. Plenty big smoke ... Breath deep before starting engine.
Good for clearing rats.
 
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