18HP Vanguard Engine Issues

[bushman69]

Hi Guys

I purchased a fairly low hour 2007 Frontier Lite with 18HP Vanguard recently knowing that it had carb issues for sitting for awhile. I have replaced the fuel lines, fuel filter, siphoned most of the gas tank out, new plugs and engine oil. After i cleaned the carb out it would run on half choke for 3-4 minutes and eventually die. I did this numerous times and didn't hear any odd noises besides the engine sputtering once in a while.

Today i noticed that one of the valve covers never got warm after running so i disconnected the spark plug wire. The engine kept running the same way which was a surprise to me. I then took off the valve cover for the front most cylinder and there was a bent push rod sitting there that i could take out. The other one looks ok.

My questions is what damage do you think occurred as it ran like this for some time and should i consider a new engine, possible upgrade? Has anyone had something fixed like this before and how much did it cost? I am worried that if i take it into a briggs mechanic next week the bill will be close to a new engine...

Your thoughts?

Thanks and great website!

[rapidroy]

The push rod likely stuck do to bad gas, varnish on the valve stem or something similar. I would just get a new push rod and install it then do a compression test on both cylinders. This is not uncommon on the water cooled kawasaki, not sure about the vanguard but it may turn out to be a cheap fix with no concerns about reliability unless there is an alternate reason for the bent push rod such as mechanical damage, broken valve spring, busted piston and such. The compression test will reveal how sound things are mechanically...good luck. RR

[Rock Doctor]

I've straightened my fair share of Push Rods, over a Stump with an Axe. Put it back in and set your gap (Piston at TDC on the Compression Stroke, .010"). Fire it up and go riding .

RD

[Bazooo guy]

And make sure you have spark on both plugs.
It will run on 1 cylinder.....the plugs should get hot before the valve cover.
Let it idle for a couple minutes,turn it off and feel the plugs.
They should both be the same temp. HOT
(Or you could take them out to see the spark).
And check that the valve is not stuck or your new pushrod will bend.
Sticking valves and high rpm = bent pushrod.

[bushman69]

Thank you for all the information everybody

I took a closer look at one of the pushrods that wasn't bent and it was worn down and shorter then the bent one. Looks like it was chewed up on the cam side? When these vanguards do this how bad can the damage be? Is there any chance the cam has to be replaced or a valve hit a piston? A local seller here has a 20 HP Vanguard (vertical) engine for a good price. I wonder if it will fit in the Argo. What details do i need to find out if it will line up such as required shaft size etc? Hopefully it wont be worse case scenario but looking at all options.

Cheers

[Bazooo guy]

. I would just get a new push rod and install it then do a compression test.
The compression test will reveal how sound things are mechanically.. RR

If the piston hit the valve it probably bent it.
You would need to pull the head to know for sure.

[Tomo]

hi
apart from sticky lifter/followers the 2 most common causes for pushrod issues is over reving and worn out cam shaft lobes[age] . Factory cams are made of a soft material compared to aftermarket units . Valve springs can get tired eg soft etc .

If the problem persists replace the above parts [replace followers with a new cam ]
Depending upon model a vertical and horzontal interchange only some parts

tomo

[bushman69]

I would think the engine had push rod issues because of the old stinky fuel that had contaminated the machine for awhile. Sticking valves maybe? I am dropping the machine off at the local briggs dealer today but thinking worse case scenario (and peace of mind when i am in the middle of nowhere in the argo) do you guys think this new engine will work?

Briggs & Stratton Vanguard 18 HP Horizontal Engine - Electric Start - NEW | eBay

Hoping its a direct replacement without any crankshaft size issues

Thank you!

[bushman69]

Well i got the Argo back from the small engine shop this week and the only issue was the bad pushrods which were replaced. The mechanic checked the compression and said everything is good - which is a a relief. It idles great and don't even need choke to start. I was happy my first argo was back in service chugging along the lake at a whopping 12MPH flat out according to my GPS. I heard argo's were slow compared to atv's but something might not be right. I remember the mechanic told me he adjusted the governor to a level that was good for the engine.

I think its way too low and maynooth marauder (nice guy) confirmed this today when i met him. His older 8x8 does twice that speed with tracks on.

So my questions is this please: How to you adjust the governor on a briggs vanguard? I looked at many you tube video's but the setup always looks different and i don't want to mess the slow albeit running machine up. I loosened the jam nut up on the governor arm but the shaft i have to turn (according to the videos) wont budge.

Thank you for your help and patience

[Mike]

If you go to Briggs' website and enter the model number of your motor you should be able to download a manual that mentions this. It's been a couple of years since I looked but I think I remember doing that for one of my older motors.

Here is a link to another PDF online that appears to have the information you are looking for: http://dc260.4shared.com/doc/gfvokLAn/preview.html

[Tomo]

HI
The governor is adjusted by typically bendinging linkages
This must be done with a tacho
If u donot use a tacho u will not even get close
The system runs a governed idle and high speed
The setup is a procedure ..
Setting up the governor shaft is the first step
As suggested download manual