18 hp vanguard need help

[mopard3]

My 02 max iv just won't run right. It idles good and drives good but on a hill or any big load it starts to bog and loose power. I have adjusted valves, new plugs, fuel filter, cleaned carb and needles, fuel pump, air filter. One plug is golden brown the other is black and wet. When it does bog I can feather the throttle to keep it going. One last question.. The fuel filter has a very small amount of fuel in it. Shouldn't that be full? Thanks!

[thebuggyman1]

The fuel filters are never full....always just under half. I've even tried bleeding the air out, and they still return to that way.

I suspect you have a bad diode on one plug wire/coil. Check spark on both plugs. Vanguards can run fine on one cyl, but lack power.

[mopard3]

Yes I have spark on both wires

[ARGOJIM]

When it bogs try running with choke partially out, if it gets better there's either a need to re clean carb or find the vacuum leak. Also check the new plugs you're going to put in now and see if it's the same issue, if so the diode may well be the problem.

[millerperf]

always check engine compression first, use gauge!

[Disabledsportsman]

Dido on checking the compression first. if they both have the same compression reading in both cylinders,then check all of your vacuum hoses for leaks. Then check your carb float bowl for dirt or water at the bottom of the float bowl. If clean,check the float to see if it my be out of adjustment or could be hanging up in side the bowl for some reason Richards relics web site has how to clean your carb and how to make adjustment to your float. Check it out the have awesome info there. I hope this helps you.

[garretttpe]

I had the same issues a cople years ago when I was trying to sell it and the customer was driving it, After doing all the troublshooting with the with the potential buyer we could not find the issue. A few days later I was looking at it and one of the spark plug wires would not sit correctly on the plug itself, everytime I removed the wire to check spark perfect, then thinking it was seated on the plug it wasnt.

[Nubs]

I have seen where the clip in the spark plug boot was not snapping onto the head of the plug, after the engine would warm up the boot would slide back off the plug just enough to allow it to arc from the clip to plug.

[mopard3]

Update: was driving over rough terrain and it would stall, I had to nurse it back with half choke. I found oil in air cleaner base and wet plugs.. comp is +\- 120 psi each cylinder, spark seems good and I checked the pcv flap seems to be ok. Everything looks good under valve cover. Thanks for the input

[ARGOJIM]

Have you checked the oil level? vg's don't like too much oil atall.

[millerperf]

if your engine has a low oil sensor on it try disconnecting it.keep digging !