Motor replacement

[ARGOJIM]

Personally I have one day with a 23hp Vanguard, but that is going to change with my 21 Frontier 650 6x6 and I will report back this summer on it, the 23 was on a Max II and was good until 1 side carb clogged in the mountains of Tn.

As far as the 23 running hot in the Argos I believe this was an engineering failure that it appears they have been chasing since the change. This change happened 02-03 when the Vanguard engine mufflers were moved in the engine bay creating higher engine bay temperatures than the earlier y pipe to muffler out on the wheel well inside a box. We have encountered many heat issues with the 14,16 and 18hp engines in Argos many of which have been lack of fuel related and one reason you see many Frontiers and Bigfoots running with out hoods in warmer temperatures, it seems Argo has tried to abate this with hood scoops and engine bay temperature extraction fans ever since. The water cooled engines with real fans seem too have had far less extreme issues yet they are still apparent to some extent. IMO this was all created by moving the muffler inside and having a less defined muffler housing such as what was in the Twin and KB/Magnum machines allowing the heat to circulate inside. Granted there were cases of melted or distorted bodies being addressed.

I remember when the flat top Internal muffler Max II was being tested Jay was running a machine with either the 23 Vanguard or the 25 Command and had said he was working on heat issues, that may have been what brought on the introduction of their fresh air intake but I am uncertain. Likely I will be trying a 23 Vanguard in my II as I am turning 25s and once it's done I'll report back on it.

I would like to know how the 23 in the early Vanguard works as it should have the outboard muffler in it.
It should also have the older Twin style body which has more engine bay area.

[Laird]

It does have the outoard muffler and had an opposed 16 Briggs twin. I built a manifold to accommodate the existing muffler.

[Cupwalker]

When I bought my machine ('02 Max II B&S 16hp Vanguard) the external muffler was completely shot and had to be dealt with before anything else. So, after reading a few posts about people relocating their mufflers to the inside of their machines I knew that's what I wanted to do and I did. Common sense and the limited research I'd done on this site told me there'd undoubtedly be an increase in the internal temperature so I thought I was aware of the potential problems but after reading this thread I've realized that I was clearly not aware!! Thankfully the only issue I experienced was the body getting too hot which was a stroke of luck for me no doubt. I've toyed with the idea of going to a higher hp motor and I considered the B&S 23 but now I'm not so sure. Eitherway, great info in this thread and I'm grateful to those whove contributed...Cup

[Simondewing]

My early Max 11 was vanguard converted by P.O. 18hp if my memory serves me correctly.
New frame, upgraded axles, bearings and sprockets etc. etc.
Goes pretty well and maybe does not need any more power.
It still runs fairly warm (with external muffler) in Texas summer temperatures without fans but its running on a replacement carb and I don't think its jetted correctly.
I need to clean out the original refit it and see if that helps any, also likely that EPA requirements make them run a little on the lean side to reduce emissions which will increase running temps.
Quite a bit of modification, to get this to work reliably in an early max.
Plan on replacing pretty well all but the body and the transmission.

Rgds

Simon

[neveroddoreven]

New B&S 23 engine came in (386447-0090-G1, mfg August 2021) today for my Max II. Of course, it was slightly damaged in shipping as seems common among the posts on this forum. Dealer says Vanguard is packing them with 3 to 4 layers of cardboard in the bottom rather than a wood base, as the wood was transferring dropped forces to the mount ears on the bottom and breaking them off. In my case, it does not appear dropped with a lot of force, but just enough at just the right angle to only dent the shroud in and barely block the fan from turning. I await dealer instructions.

While awaiting, I also ordered an electric pump 1-2psi to avoid pulse pump problems, and tomorrow I will take the no-engine Max II to a shallow lake, while it's still free of gas/oil/lead acid, but loaded with same weight in bricks, and see how well its bearings keep the water out. I figure it's easier to clean up now than after I re-power it. Small battery will run the winch and bilge pump, should they be needed (-:

I'll stop posting here and later start a new thread with my progress on the B&S 23 re-power, as I plan to do additional changes and take comprehensive readings.