mrpip

Greetings,y'all. Have conciderable problem starting my MVVS 35 cc petrol engine. Frequent backfires or no kick at all. After an hour or so with plug in and out, checking battery and exchanging batteries finaly starts. Runs well then after cool down same difficulties. What may be wrong. Suspect Vlach ignition problem. New one costs about $ 165.00 Canadian. Has anyone a suggestion to rectify the problem? Tnx much
mrpip

aussiesteve

A little more information would help.

Has it been doing this since new or is it a problem that has just cropped up after working fine for a while?

You mention that after changing batteries it finally starts, What battery are you running, how old is it and is it in good condition?

Are you getting a healthy spark at the plug?

IF it is the ignition that is faulty (and with the Vlach it is a good possibility), the fix I use is one of the following.

1 - Replace the ignition with the new style ignition that isn't a Vlach unit.

2 - Take a coarse file and file the sensor mounting lugs down until the front of the hub is round. Finish off with a finer file. Then install a CH Ignition (now available from Adrian) or an RCExcel unit.

Mr67Stang

An ignition problem that has recently boggled me, that I too thought was a modual problem, turned out to be the magnet in the timing ring/flywheel. Mine had lost all of its magnatism so it was not sparking at all. You can test yours by removing your spark plug, plugging it into the plug boot/cap, turn the ignition on and rock the prop back and forth so that the magnet passes the pickup/hal sensor. If this provides consistant spark then your magnet is fine. If it does not, remove your hall sensor and get a good magnet and test that it produces a consitant spark as you move the magnet closer to and away from the hal sensor (I've used the magnets avalable at auto parts stors for picking up nuts and bolts when you drop them under the hood). If this second test shows an improvement then your magnet is losing pull. If it is the same and still inconsistant then the problem is either the hal sensor it's self or the ignition modual.

mrpip

Thanks for your quick response re MVVS 35 starting problems. Yes I have checked for the spark but have not determined if its working consistantly
and the problem has been consitant since new but not to its sevierety as now. Will check the spark strength again. Your thoughts of a new ignition purchase may be the best alternative. Will check out the cost.
I have some hasitation with filing things on the engine. I am not an expert in these matters and am afraid to foul things up. Thanks again for your assistance though. Regards

mrpip

Thanks for your reply. I have not checked the magnets. Will do so and if necessary change them. It would be the quickest remedial action.Will let you know. Regards

pe reivers

One more thought:
The Vlach ignition needs a resistor type plug. Non-resistor types show the behaviour you mention.
As alternative, get aMVVS/MSR conversion unit (plug/play), or an RCexl unit like Steve suggested.