MZ Skorpion sport cup hot rod

[twinlinemoto]

Hi All,
First post!
This forum seems to be the only wealth of information for MZ's, so I figured Id join and ask a good question.

I have a 1995 MZ Skorpion sport with a sport cup tail section and exhausts with carbon fiber cans, Carillo rod, Arias 690cc 11:1 piston with an LA sleeve, Megacycle stage 2 cam and upgraded valve springs, head flowed by George Dean, 45mm holeshot carb kit with a UNI pod filter.

This bike sat outside for the last 6 years before I picked it up. I cleaned the carb vigorously, checked the valves (exhaust were at spec, intakes were a little loose, set to 0.007"), changed the oil, and re-fitted a spark plug.

After giving it fresh gas, all it wants to do is backfire out of the carburetor. I put my hand over the carb mouth while cranking it over and it does not seem to suck an awful lot, there is a definite blowback too. I have not checked cam timing as there is no reason it should be out, but that definitely seems like a cam symptom, right?

Any thoughts on this scenario are greatly appreciated.

[edfmaniac]

What ignition does it have on it? If it's a programmable, see if you can find someone that will let you borrow their stock box long enough to see if it will crank. Although my bike runs on both boxes, I could never get my programmable dialed in enough to start the bike dependably. I ended up putting a switch just so I can start on the stock box and run on the programmable.

[tigcraft]

Corrosion on valves since it's been left possibly with one open for so long. Possibly why not much suction.

[samandkimberly]

Corrosion on the valves is a possibility, but if it was real bad then the intake clearance would have been loose.

It sounds like the engine isn't getting fuel. I'd try starting fluid - see if it runs OK when a sprayed into the carb, ideally with the air cleaner removed. If that does work, you can also try spraying around the intake manifold to see if you have an intake leak. If the starting fluid doesn't work you've almost certainly got an ignition or mechanical issue.

Sam

[twinlinemoto]

I believe it is the stock ignition box, its definitely not programmable. I can visibly see the accelerator pump squirting fuel down the throat of the carb, so I know its getting fuel, which also explains the backfires out of the carb. I did find an intake leak between the carb boot and the holeshot manifold, but I re-sealed it and now its air tight. Intake valve corrosion is a definite possibility, the intake valves were all loose as previously stated.... Can I get around this? or will I have to pull the head and clean the valves?