I have the MVVS 45 and I'm having alot of trouble setting the low end. I usually put a pipe on the fuel inlet and blow while turning the low end needle little by little till some air comes out. this has always worked good but on the MVVS I ca't stop the air from flowing even with the needle all the way in. Is that the way their carb is designed or should I order a new needle valve assembly?

Thanks
Pat

Hello Pat
MVVS has releaste a replacemet needle asembly that cures this problem and makes the engine work very well.
Tomas

Thanks alot this problem was driving me nuts!!!

Pat

Does the same apply to the 49 ?


Anyone running one of these ?

The low needle on my 49 is pretty sensitive. A slight tweak in or out can make the difference between an engine that transitions perfectly and one which sputters or dies. I think it may be vibrating out slightly in flight.

I generally tune this one based on how it transitions from idle to WOT. If it sputters I lean the needle; if it shuts down I richen. The engine is pretty new, thought - I'm hoping that things will settle down some once I put some more time on it.

Hi, With my problem it will transition pretty good when the low end is out only about 1/4 turn. If I tilt in in any direction WO or idling it runs great for a whole tank but after I'm in the air it will stall after about 30 seconds. My engine is used and I only have it a week. I never had a problem like this before. Do you have any thoughts ? Could it be anything else besides the needle?

Pat

Zoned,
If i understand correctly, you are saying if the plane is on the ground it will run fine but once airborn it will stall..
maybe there is excessive vibrations to the tank while in flight which are causing air or foam to go through your fuel line resulting in a hot run untill dead stick. Something is happening in the air that is not happeing on the ground. It could be a number of things.
The prop is so off balance that in the air it shakes the whole plane.
the vibrations from the eingine are shaking the tank and causing foam.
whne the plane comes down dead, is the engine too hot to touch?
is your tank surrounded with foam?
have you chekced the clunk line in the tank? that's something I always find problems with on my planes..
Have you checked to make sure the clunk is still attached to the line?

Hello!
Being the sedish importer of MVVS engines I can tell you that MVVS have a replacement carb for the
3,5-4,9 cc engines. The carb is the same for these engines haveing a 7,5mm intake hole and a butterfly-valve instead of the drum-valve intake.

This carb is a duplicate of an OS carb and works better than the standard MVVS carb.
MVVS also have a super quiet silencer fot these engines, if you do not want to use the noisier minipipes.


Regards!
Jan K
Sweden

Hi, I ordered a replacment carb and she said it was the new one they are using now but it doesn't have a butterfly valve. It is still the barrel type valve. The needles are different and it is tighter than the old one.

Pat