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-   -   leaky super tiger (http://www.rcuniverse.com/forum/sport-flying-373/11597991-leaky-super-tiger.html)

aggieman 04-22-2014 10:14 AM

leaky super tiger
 
I have a new super tiger gs-.40 (ringed), breaking in on red max 15% nitro16% synthetic,40% caster . The engine is ok but the head leaks,I would hate to just set the engine aside and go to something else.What would some of u guys do to try to fix the problem?

speedracerntrixie 04-23-2014 03:52 PM

I have never seen an engine leaking from the head. Usually it is a leak elsewhere and the fuel accumulates on the head. Can you give a little more info? The other thing is I personally won't run any fuel with less then 18% oil and I prefer 20%.

thailazer 04-23-2014 04:18 PM


Originally Posted by aggieman (Post 11788251)
I have a new super tiger gs-.40 (ringed), breaking in on red max 15% nitro16% synthetic,40% caster . The engine is ok but the head leaks,I would hate to just set the engine aside and go to something else.What would some of u guys do to try to fix the problem?

Have you taken the head off to see if there are any manufacturing burrs that are keeping it from seating completely? I have seen that before on some engines where the head is a low clearance fit. All it takes is a bit of binding and you will see bubbles.

aspeed 04-23-2014 06:30 PM

Sometimes the finned heads warp a bit. It should be under warranty if they are still in business. It could be lapped out and carefully cleaned if it isn't too far off. Any scratch or dimple from a piece of dirt on the surfaces could leak. I sometimes use castor oil on the mating surfaces and found that it seals a bit better, other people find the opposite true. 400 sandpaper on a piece of glass and some careful twists can flatten the top of the liner before lapping the head.

mashp39 10-10-2015 04:56 PM

I bought a tired and worn LA 46 once that seemed to have no power. I noticed it was making air bubbles around the head. Yes, the head bolts were loose.No wonder it was sold cheap. The head bolts were tighted when the engine was hot and then the motor had much more power. It pays to check all the bolts. You will be surprised.

CK1 10-11-2015 06:22 AM


Originally Posted by aspeed (Post 11789440)
Sometimes the finned heads warp a bit. It should be under warranty if they are still in business. It could be lapped out and carefully cleaned if it isn't too far off. Any scratch or dimple from a piece of dirt on the surfaces could leak. I sometimes use castor oil on the mating surfaces and found that it seals a bit better, other people find the opposite true. 400 sandpaper on a piece of glass and some careful twists can flatten the top of the liner before lapping the head.

+1 , also be sure the headgasket/ shim is in place and not damaged .

52larry52 10-17-2015 09:03 PM

+1 on tightening the head bolts before you go disassembling the engine. Torque the head bolts in a crisscross pattern. It will have 4 metric allen head bolts. Mark the position of each bolt head with a white crayon, then one at a time, loosen and retorque each bolt and observe your white crayon mark to see how much further you pulled each bolt down. Each bolt should at least return to the original position and hopefully an eight to a quarter turn more. Rerun the engine to see if the head gasket leak is fixed and if not, then remove the head to replace the gasket and check for surface flatness. If you do have to replace the head gasket you will still have to properly torque the head bolts and go back and retorque them after a short run time.


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