Thanks Noel Woods for the detailed reply. What manufacture year or year range was your past B&S 23 experiences? Also, a correction to my last post, the fans I planned to use are 80W 650CFM but based on your reply they now seem underpowered. My Max II came to me with all the panels cut out around the engine bay for increased airflow. I am still thinking and planning.
Year 2011 or so. There are other folks on the forum that have chided in on similar posts indicating an on-going issue with this series of motor however.
i think noel's reply regarding a b and s dealer saying these engines were never designed to be enclosed in compartment type spaces pretty much sums it up . if they are used in such places like a max or argo machine , the key is plenty of air exposure and fans , etc. if i'm riding in warm weather for a few hours i just turn the fan on and leave on, sucking all the warm air out . i moved my fuel pump too but that did,nt solve the problem . no problems today riding in the snow with temps . around 33 deg. have fun , johnboy
Thanks Noel Woods and Johnboy for your input. I'm going to gamble on the B&S Vanguard 23, specifically 386447-0090-G1 which is the latest revised model with a one-inch crankshaft 2-29/32" long, having a 1/4" keyway and 3/8-24 internal tapped hole. That's what fits my old existing Comet clutch 300421. I'm going to wire it up with multiple thermistors and start tracking heat levels, and see if I start hitting power losses or other weird behaviors. I will let you all know what I find over time.
Does anyone know what the normal operating temperatures ranges are for these kinds of big block air cooled engines? Oil temp, block temp, temp for earliest onset of vapor lock, and as for the fuel pump melting I'll check on its actual materials to see what has the lowest glass transition temperature.
I have installed a 23 Briggs in a 91 Argo 6x6 Vanguard. I am a firm believer of the vanguard engine due to several years as a small engine mechanic. I have repaired Kohler, Kawasaki, Honda and offshore engines. They all have issues. I have not run into overheating with the Argo as yet but I also don't run mine for hrs on end in the hot summer heat. My primary use is fall and winter short runs to my hunting area. I also chose the briggs engine because of past experience. Also, just about every small engine repair place carries Briggs parts or quick access to parts. I have found that parts are relatively less expensive. In my search for a running temp on the 23 Vanguard, I have seen cylinder head Temps in the 400 to 450 F. My egine runs around that point. I have a airplane cylinder head temp gauge for a two bank engine so I get a separate reading for either cylinder. ( not recommended as it is not in fine enough increments. I will replace the unit when I find a suitable unit). It should be noted that I don't have the recoil start on the engine (came without one ) the oil cooler is mounted in the cold air intake, the exhaust is wrapped and I have a 7 in. automotive style fan also mounted in the cold air intake blowing directly into the cooling fins of the flywheel fan. I haven't had to actually turn the fan on yet but also just finished the project for the fall hunt.
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.
Last edited by ARGOJIM; 01-19-2022 at 02:16 PM.
My new beer holder spilled some on the trails - in it's hair and down it's throat.
Joe Camel never does that.
Advice is free, it's the application that costs.
It does have the outoard muffler and had an opposed 16 Briggs twin. I built a manifold to accommodate the existing muffler.
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
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
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.
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