3300 Flywheel spacer mod

[facthunter]

It IS a different thread diameter. ( the Jab being smaller) Nev

 

 

[gandalph]

It IS a different thread diameter. ( the Jab being smaller) Nev

Ah! Yes of course, But still available I'd have thought.

Are dehydrator plugs worth the trouble & expense? Wouldn't sink plugs to block the exhaust pipes and an oily rag at the airbox inlet do the job? I'm nowhere needing something like that yet but it has got the grey cells percolating. Perhaps a fair way off topic for this thread though

 

 

[facthunter]

It's all part of the stipulated procedure by CASA. When the plugs (dehydrator) change colour you replace them. You may be able to dry them out and reuse them. I reckon rust is one of the problems with motors with steel cylinders, used only occasionally . We don't treat it seriously. The Rotax has no problems there. They are Nikasil, but sometimes the exhaust valve stems will corrode over time. Nev

 

 

[Oscar]

Actually, there is a (sort of) relevance: rust in the bores will increase friction and that will add load to the flywheel bolts - especially in very cold weather when oil is thick etc. plus the bolts start to get to the temp. where they become more brittle than usual.

 

I have the CAMit inhibitor mod. in my engine, but I know there will be occasions when I'll be not flying for periods of more than several weeks at a time and I want to be able to simply pop a plug out of each cylinder and screw in dehydrator plugs without having to remove the cooling ducts, so the dehydrators I've made up will fit neatly through the standard Jab. plug lead holes. It's belt-and-braces stuff, but to me it isn't time wasted to make them (and they're actually not as simple to make as I had thought!) when I've spent a heap of time and $$ doing up the engine from scratch. And Nev's point re exhaust valve stems corroding is well taken.. as Niel Young said, 'Rust Never Sleeps'.

 

 

[dazza 38]

Why don't they just Nikasil the bores ?

 

 

[gandalph]

Thanks Nev & Oscar. I'll do some more research.

 

 

[gandalph]

as Niel Young said, 'Rust Never Sleeps'.

Turning Japanese?

 

 

[facthunter]

Nikasil. Trade name.......It's only done on certain aluminium alloys and steel is much stronger than aluminium in tension. Noticeably worse in conducting heat (Steel) Not many aircooled Aero engines have alloy cylinders Franklin and Bentley BR2 rotary being the only other ones I can think of at the moment and they have cast iron liners.. (apart from the Rotax 912. Nev

 

 

[Oscar]

Turning Japanese?

Ha Ha.

 

 

[OZJohn]

Limbach have been using nikasil treated cylinders for at least 25 years. A lot of racing motor bikes have them done - electrosil.

 

John.

 

 

[facthunter]

It's almost universal in racing two strokes. Nev

 

 

[dazza 38]

And people wonder why I own KTM motorcycles which are made in Austria, the same country where Rotax 912 engines are made. Simple realy, I want the best.

 

PS- well the expensive ones, some are made by monkeys in Asia, the cheap ones.

 

 

[facthunter]

KTM went bad in the late 90's. They have recovered and have the performance now. Not sure they last forever. There is no ONE.... GOOD the OTHER..... BAD In all this . It's not that simple. There is something wrong with all of them. NOTHING's perfect. Nev

 

 

[dazza 38]

KTM went bad in the late 90's. They have recovered and have the performance now. Not sure they last forever. There is no ONE.... GOOD the OTHER..... BAD In all this . It's not that simple. There is something wrong with all of them. NOTHING's perfect. Nev

They were a small niche manufacturer back then. They are now the biggest manufacture in Europe.

PS- i have been ridng KTM motorcycles for 15 years and they have been perfect to me.

 

Ps- im pretty sure there are Jab engine owners wishing the same thing.