MAX II belt replacement

[hipowerone]

This is probably a dead horse, but....

Back in 2016, after I got my MAX II, I had power issues, and after a few posts, I thought that I might have to replace my belt, but I found that by adjusting my belt, as it was not badly worn, I was able to get better power.

However, now, several years later, I find my belt is 1 1/16" or less and is due for replacement. I looked back at previous posts, and at one time Mike told me that there was info in the user manual on how to replace the belt. After having found that link again, and re-reading it and the user manual, I only see information on how to adjust belt tension.

I then found a link to an older post by Mike on MAX II engine replacement, including photos.

I have looked at my machine, and this is what I think needs to be done. Correct me if I am wrong.

1) loosen two nuts on the anti-flex mount bracket
2) loosen and remove the 4 engine mount bolts.
3) it appears that I will have to also loosen and remove the 4 exhaust manifold nuts/bolts and totally disconnect the exhaust.
4) lift engine off the mounts and move forward and to the side to allow belt removal.

It appears the reverse is done after installation, then adjust belt tension, and tighten engine mount bolts and anti-flex mount nuts.

And on a related note, to what value should engine mount bolts and manifold bolts/nuts be torqued, if known.

Now I am really looking forward to doing this task! I can imagine with a new belt, my MAX II will have new life!

I have plenty of time, and I am in no rush, so I will wait for some confirmation, before proceeding further.
Thanks to everyone in advance. This forum is truly a knuckle saver.

[hipowerone]

After over 5 days and over 800+ views and no response, I gambled today, and used my above checklist and attempted replacing belt. It was not easy, mostly because of my age and portly belly, but I managed to get the job done. I am going to use the machine a few times, and then readjust the belt. It is better but not great. Maybe with some more belt tension? I still would like to know if there are any known torque settings for the engine mount or exhaust manifold bolts/nuts. I am also looking at plug wires as a possible issue. I will be testing them and also checking engine RPM's both idle and full throttle.

[tbone9]

You stated that you have power issues. Maybe if you could elaborate on that someone may chime in.Exactly what is it doing of not doing?What are the symptoms? When does it do it?

[hipowerone]

Thanks TBone9.

I have been in correspondence with several people on this issue (including Andy/Andrew at sales@maxatvs.com) , and so at times I forget who I have informed and who I have not.

The 14HP Vanguard Twin just seems plain lazy...the best GPS speed on level ground that I have achieved is 12MPH, which Andy says should reach 20-22MPH. It is very sluggish going up hills and struggles to climb over some objects (4-6" logs). I have now run it 3 times since the new belt, and will open the tub soon and readjust the belt tension. Hopefully, that will make some improvement.

While I am not a mechanic, I do know enough to be dangerous and I have assisted an A&P mechanic in doing SEL airplane annuals. Back in the days of coils, wires, plugs, points, caps, rotors, and condensers, I was once pretty good at doing tune ups on my car engines, using an analog engine analyzer and strobe light. My analyzer is a bit old and just does not like this 2 cylinder engine.

I have tested plug wires, but I am a bit skeptical about results, as what I am seeing and what I have as a running result are two different things. Spark tester shows what appears good spark, on new plugs, but the current situation is as stated.

I have replaced all fuel lines, pump, filter, new fuel, etc, and pulled and cleaned the carburetor and replaced gaskets. I am trying to locate a tachometer to check engine RPM's at IDLE and full throttle. That may indicates something as well....throttle adjustments and carburetor adjustments.

If further belt tension adjustments do nothing, there are a couple things that I have considered. One is a possible faulty/stuck valve, but I do not have access to a compression gauge. The other is a faulty coil/magneto. When the engine is running, and warm, it does not smoke or use oil, so I believe the rings are good. I am trying to contact a fellow that I know who works on small engines to see what he might suggest.

In the meantime, I avoid long rides far from home and anything more than moderate hills.

[tbone9]

Does the hand throttle have play in it? It should rev as soon as you work the lever. Sometimes the set screw that holds the cable on the carb slips.

[msafi65]

Do you have access to an electronic tachometer? Sounds to me like the engine isn’t getting full rpm. I set the governor to 4100 rpm on the Briggs with belt installed. With the transmission in neutral or reverse, run the engine at full throttle for several seconds and observe the clutches. The engine clutch should close completely bringing the belt near the outer edge. If the clutches won’t convert all the way I suspect lack of rpm’s. Governor or throttle cable adjustment.

[hipowerone]

msfi65: Thanks, as I stated, I am trying to locate a better tachometer. Once I have one in hand, I will tinker with this beast again.

[msafi65]

I’ve had a tinytac for about 30 years. Just wrap a lead around the plug wire and ground the other.