Welcome Guest [Log In] [Register]
Welcome to CCM MaD. We hope you enjoy your visit.

If it's your first time here please make your first post in either the 'Welcome' or 'Chat' section so we can verify your account quicker, untill verified your posts will need to be manually approved before they show, please be patient.


Join our community!


If you're already a member please log in to access all of our features:

Username:   Password:
Add Reply
Top end overhaul; Rotax issues
Topic Started: Oct 9 2016, 12:21 AM (492 Views)
Tombs
Commoner
[ * ]
Morning gentlemen. Got a wee problem. Suspected burnt valves on the rough rotax. So I'm just gonna whip the head off for my own peace of mind. Valve clearances were set at 0.05 which as far as I'm concerned is too bloody tight and as a result think the valve seats are a bit Krispy... only getting 108 on comp test. And being a pernickity bastard can't get the fucker to run to my satisfaction. If I can build chevy engines cranking 400 plus horse I refuse to be beaten by my rotax lol. Any advice is appreciated. Oh and the initial point was where can I get a top end gasket set?
Offline Profile Quote Post Goto Top
 
Monty
Member Avatar
Charlie Big Banana's
[ *  *  *  *  *  *  *  *  *  * ]
The rotax uses O rings, no gasket, O rings for sale in for sale section.

I always lap the head and barrel mating surfaces in as well,

I also set my valves at 4 thou in 6 thou ex, never had any probs, Gary at sportax does set his at 2 thou which is what the manual states

You may have to remove the engine mounts and starter motor, so the engine tilts as far forward as it can to get the head free, I'd also do the stem seals at same time, Gary will have these
If it aint sharp I can play with it
My Utube Channel, lots of bike vids here. Subscribe if you likehttp://www.youtube.com/user/choppermark?feature=watch

Posted Image
Offline Profile Quote Post Goto Top
 
Tombs
Commoner
[ * ]
Excellent. Thanks bud. This f****r will run and it'll bloody well run properly
Offline Profile Quote Post Goto Top
 
Ant P
Viscount
[ *  *  *  * ]
Whats best used to mate head and barrel surfaces? Heard rumors of hylomar? But never used it?
Offline Profile Quote Post Goto Top
 
Gonzo250
Member Avatar
Working-class moto psycho
[ *  *  *  *  *  *  *  * ]
Don't need any goop to stick head and barrel together. As Monty says, spend a bit of time with some fine grinding paste and lap them together, job's a good'un.
I drink too much, I swear too much, I ride too fast and I crash too often.

It is a universal impossibility for me to leave my tools alone and my bikes standard. 'It must go faster!!'
Offline Profile Quote Post Goto Top
 
Monty
Member Avatar
Charlie Big Banana's
[ *  *  *  *  *  *  *  *  *  * ]
Ant P
Oct 9 2016, 07:12 PM
Whats best used to mate head and barrel surfaces? Heard rumors of hylomar? But never used it?
you dont use anything, Just 3 O rings
If it aint sharp I can play with it
My Utube Channel, lots of bike vids here. Subscribe if you likehttp://www.youtube.com/user/choppermark?feature=watch

Posted Image
Offline Profile Quote Post Goto Top
 
Ant P
Viscount
[ *  *  *  * ]
Cool. Thank you
Offline Profile Quote Post Goto Top
 
Tombs
Commoner
[ * ]
It's alive. And it won't wheelie. Just shreds the back tyre. Good fun
Offline Profile Quote Post Goto Top
 
Tombs
Commoner
[ * ]
Okay new development... it is pumping oil up out the clutch cable tube on the clutch case.... any ideas?
Offline Profile Quote Post Goto Top
 
Monty
Member Avatar
Charlie Big Banana's
[ *  *  *  *  *  *  *  *  *  * ]
either the O ring has gone on the cable, or you have too much oil in the bike, or your breather is blocked
If it aint sharp I can play with it
My Utube Channel, lots of bike vids here. Subscribe if you likehttp://www.youtube.com/user/choppermark?feature=watch

Posted Image
Offline Profile Quote Post Goto Top
 
Tombs
Commoner
[ * ]
Aye well it is literally pumping the fuck out. The oil is halfway up the sight tube on the frame when it's running
Offline Profile Quote Post Goto Top
 
Gonzo250
Member Avatar
Working-class moto psycho
[ *  *  *  *  *  *  *  * ]
Check breather from rocker cover to frame, and I believe there''s one by the generator cover behind the sprocket cover.
I drink too much, I swear too much, I ride too fast and I crash too often.

It is a universal impossibility for me to leave my tools alone and my bikes standard. 'It must go faster!!'
Offline Profile Quote Post Goto Top
 
Sportax Racing
Anything & Everything ROTAX
[ *  *  *  *  *  *  * ]
You need one of these... http://sportaxracing.co.uk/shop/mt-parts/clutch-cable-boot-kit/ or maybe a new cable...

If i dont cork the hole off when an engine is on the test bed oil is soon spraying out of the hole...
www.sportaxracing.co.uk
Offline Profile Quote Post Goto Top
 
ZetaBoards - Free Forum Hosting
Create a free forum in seconds.
« Previous Topic · 604 DS & R30 · Next Topic »
Add Reply