Getting frustrated with 18hp Vanguard

[wjs0311]

I have a 18hp Vanguard with 14/16hp heads, thin head gaskets, and gov removed. The engine has not ran right since I put it in the hustler. I had it sitting in my garage as a backup for my power washers. I had the carb on my 14hp while it was in the hustler and it ran fine.

When I take off it instantly bogs down no matter where I have the choke at. If I stay on the gas it sounds like it is running on one cyl and it blows black smoke out of the exhaust. If I just rev the engine while stationary it seems fine.

So far I have emptied the gas tank and cleaned it out, new fuel filter, new plugs, cleaned the carb and blew it out, drilled the main jet, adjusted the float and idle screw, and banged my head against the wall.
I am getting close to just pulling it and grabbing a predator. I have a 23hp cam I would like to put in at some point but I'd like to get it running well before I do it.

Any ideas?

[Rabbit929]

Change out the fuel lines would be a good start.
Mine had bits of the old fuel line coming apart after the filter, this new ethenal gas disintigrates the older lines.

[msafi65]

Black smoke is usually to much fuel. Have you tried it with the air filter out. I've had very nice looking ones that were restricted enough to choke it out.

[eddieb1965]

Why did you drill the main jet? Were your plugs very light gray and under a very lean condition?.If they werent there may be your problem.How big did you go on drilling it out?

[Nubs]

its running out of air, a 14hp carb will never run a 18. drilling the jet just dumps to much fuel and no increased take in air. the 23hp cam is just smoke and mirrors and will do nothing in the end.
your increasing the compression and rpm's, timing also i'm guessing so unless you feed it right it will never run

[ARGOJIM]

Try running it without the air filter and see what happens, personally I've had issues with the foam part of a filter and generally toss it after the first couple rides with no oil on filter. The oil on the foam filter can hurt tremendously.

[wjs0311]

Same issues without the air filter on. Nubs the carb that is on now is the 18hp carb. Eddieb that problem was there before I drilled out the jet, I'll get you a bit size here in a little bit.

[racerone3]

Check for spark on the cylinder closest to the rear of the machine. If the diode in the kill wire under the flywheel shroud burns out, you will loose spark there. A brigs will idle fine and Rev up with no load on one cylinder. Black smoke from all the unburnt fuel trying to burn off in the muffler. I battled the same symptoms a few years ago on one

[ARGOJIM]

Check for spark on the cylinder closest to the rear of the machine. If the diode in the kill wire under the flywheel shroud burns out, you will loose spark there. A brigs will idle fine and Rev up with no load on one cylinder. Black smoke from all the unburnt fuel trying to burn off in the muffler. I battled the same symptoms a few years ago on one

My question also.

Is it possible the float is way low or the gasket is ripped allowing bowl gas into the venturi?

[thejunkman]

How much bigger did you drill the jet out it doesnt take much i take it your plugs are black?

[wjs0311]

The drill bit is a 1/16th. I have a extra jet that I could replace if I went too big.

[wjs0311]

Also I am getting spark on both cylinders. I will post a video later.

[flippy]

so much easier to just go to harbor freight and buy a honda clone engine.I have bought three and couldnt be happier.I replaced a briggs flat twin 16 hp,replaced 2 sachs 2 strokes.Quiet,good on gas,powerful.I dont care what people say about briggs engines,I have experienced their ignorant plastic geared starter that strippes out due to the pot metal flywheel,then when you upgrade to the steel gear starter gear,the pot metal flywheel strips out.Numerous bloggs.Just my opinion ,time is valuable and I lost alot of it rebuilding carbs changing gaskets troubleshooting stalling issues,the clone engines are made for todays ethanol type gas.

[wjs0311]

so much easier to just go to harbor freight and buy a honda clone engine.I have bought three and couldnt be happier.I replaced a briggs flat twin 16 hp,replaced 2 sachs 2 strokes.Quiet,good on gas,powerful.I dont care what people say about briggs engines,I have experienced their ignorant plastic geared starter that strippes out due to the pot metal flywheel,then when you upgrade to the steel gear starter gear,the pot metal flywheel strips out.Numerous bloggs.Just my opinion ,time is valuable and I lost alot of it rebuilding carbs changing gaskets troubleshooting stalling issues,the clone engines are made for todays ethanol type gas.

This is pretty much where I am at. I would still tinker with the briggs and see if I could get it running right but I am getting impatient. I just want to hit the trails and a few mud holes!!!!! Both my power washers have briggs 16hp on them and I have had no issues but they run at a constant speed. Does the coupons still work for the 22hp predator at HF?

[ARGOJIM]

Last 25% said exludes ....Predator..., have you replaced the main jet with a stock or smaller jet? If you have a stock 16 carb setting around give it a try, what I've heard is drilling jets with a number bit size one at a time until you are good as you may have leaped where you only needed a hop.
Nubs swears by the Mikuni change over, easily adjusted and optional venture sizes.