Joda76 Posted February 11 Report Share Posted February 11 (edited) Hello good people. I bought my self a cheep defective Ossa. It is in a rather good shape, only inner head gasket is blown. After cranking it pops like a champagne when opening a radiator cap. Coolant that I have drained smells on gassoline. As I can see 4 side bolts will be the problem to torque with my Nm torque wrench because of a frame interference . Should I use some special tool , or release engine in front and pivot it a bit to make some clearance? One more thing. I read that inner oring is better to be silicone than NBR one, any oppinion on that? Many thanks ! Edited Sunday at 08:41 AM by Joda76 Quote Link to comment Share on other sites More sharing options...
kurtas Posted February 11 Report Share Posted February 11 Silicone has a higher heat tolerance than NBR, so if you can that would be better. Both will tolerate the Glycol. 1 Quote Link to comment Share on other sites More sharing options...
pauls320 Posted Monday at 01:26 AM Report Share Posted Monday at 01:26 AM Be a good idea to inspect the o-ring grooves in the back side of the head for cracks. The exhaust mount bolts to the head stay and if the suspension is bottomed out it tags the header pipe and levers against the cylinder head , have seen it fracture the head in the mentioned location ..hopefully yours is okay 1 Quote Link to comment Share on other sites More sharing options...
Joda76 Posted 2 hours ago Author Report Share Posted 2 hours ago On 2/16/2026 at 2:26 AM, pauls320 said: Be a good idea to inspect the o-ring grooves in the back side of the head for cracks. The exhaust mount bolts to the head stay and if the suspension is bottomed out it tags the header pipe and levers against the cylinder head , have seen it fracture the head in the mentioned location ..hopefully yours is okay Great point! Thank you for advice. I will inspect. I was just checking if the head is flat, while waiting on o ring shipment. Managed to take a head off pretty easy but thinking about changing 25mm T25 M5 bolts with a hex kind, so I can torque them without engine out. Or if I take engine out to drill 2 holes into a frame and weld some small pipes inside of those holes to strengthen frame in drilled points, so I can use those holes to reach 2 most critical head bolts to reach. Also planed to make a comment about a muffler. I mean, even though I really respect Ossa's designe team work in many ways, making muffler into a prying tool for an engine head is such a bad idea. I am seriously considering doing some mod to dissconect muffler fron an engine. Quote Link to comment Share on other sites More sharing options...
Joda76 Posted 2 hours ago Author Report Share Posted 2 hours ago On 2/16/2026 at 2:26 AM, pauls320 said: Be a good idea to inspect the o-ring grooves in the back side of the head for cracks. The exhaust mount bolts to the head stay and if the suspension is bottomed out it tags the header pipe and levers against the cylinder head , have seen it fracture the head in the mentioned location ..hopefully yours is okay The moment I read your comment my friend I had that feelung, fleshing image in my head that I could not see anything wrong on old o rings. So after ansvering first I imediatly took my magnifying lens. And voila...😢 Quote Link to comment Share on other sites More sharing options...
Joda76 Posted 2 hours ago Author Report Share Posted 2 hours ago Any one have a head to sell?🤕 Quote Link to comment Share on other sites More sharing options...
Joda76 Posted 27 minutes ago Author Report Share Posted 27 minutes ago (edited) OK, I found one more next to it and next to a muffler mount (photo1),it was almost invisible util I started digging into it.... next one in line further away from muffler mount (photo2). Edited 21 minutes ago by Joda76 Quote Link to comment Share on other sites More sharing options...
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