Vak 1 running badly!

Posted by darwing1200 on 2010-02-14 20:23:00 

Hi all, I was wandering if anyone could help me I havnt a great mechanical knowledge but my vak is running very uneven if thats the right term and cutting out. requiring the choke again to start. but does start. I cleaned the fuel bowl but not sure what else to look for. any help much appreciated. thanks Darwin.
Posted by: Guest on 2010-02-14 20:42:00 
Darwin. It could be your fuel mix if you've done your own TVO but it should run on kerosene and not TVO strictly speaking as the K in VAK gives the clue. The carbourettor is a very fiddley thing to set properly that needs fine tuning of the needle on the knurled nut. Also check the electrode gap on the plugs, should be between 20 to 25thou and if you're on the mag ignition your points gap should be 15thou when open. Also check the HT leads on the mag for continuity and if you have suppressor caps on the ends on the plugs chuck them and get the proper flat brass end ones. That's what I would try.
Posted by: darwing1200 on 2010-02-15 19:23:00 
Thanks for your help powerrabbit, I should have said but never had her on tvo, petrol only. I took plugs out and cleaned them seems to have cured. Il see what happens when take her a run. Darwin.
Posted by: broadsword on 2010-02-15 23:18:00 
Darwin,

good to find someone with a limited mechanical knowlwdge as well!!!. Not an expert but I think the VAK and Cropmaster run special spark plugs but this is more important when running on TVO/kerosene rather than petrol only. All the items Powerrrabbit has mentioned are importent in getting the right spark at the right time but only if the plugs are in good fettle and the correct ones.

ps - running on petrol means you miss out on that lovely TVO/kerosene smell 

Good Luck

Andy
Posted by: Guest on 2010-02-16 09:27:00 
The original type of spark plugs were 18mm long-reach of which the Champion equivalent now are the Com 8 ones. If you can source these plugs with 3 electrode legs on the buisness end that's what the originals had, more spark to ignite the kerosene. The modern plugs don't perform like the original type did and that's why people have running problems with them on any kero/TVO engine.