New (to me) Max II owner

[84td]

Hey Y'all. Bought a 97 Max off craigslist. After reading on the site I was able to get most things to working order. Adjusted all the chains, bands, fluids, cleaned the carb and its working much better now. Figured out from reading that the trans makes some crazy poping noises but they went away after a quart of lucas atf and additive.

A few questions I have for my fellow max owners are...

Is it normal for the exhaust to glow red from running the engine at max rpm?

Is it normal for the clutch and pulley to use only half of the available surface on their pulleys? photo(7).jpg Seems like if it was using all the available pulley face it would be faster, its kinda slow now.

IF that is normal is there a way to mod or adjust it to make it faster?

All the lube points I have found is the 2 jack shafts and i behind each wheel. Any others?

Still trying to find a stumble in the engine, at steady rpms it kinds surges just a little and when the RPMS slightly drop from the surge there is a faint poping from the carb. 18HP vanguard

any advise is welcome.

[Mike]

Congratulations on your Max. Your exhaust shouldn't glow like that just from revving it up. It may be clogged with mud. The outer exhausts on Max IIs are bad about getting mud up the exhaust tip. Look inside the exhaust and see if it is open. The mud will typically build up right at the end where you can see it. It may even be worth taking the muffler off and checking it if you can't see anything with it on the machine. That could be causing some of your engine issues as well.

As for the clutches, your belt should be riding fully to the top and bottom of the clutches. Check to see if it is the right width and make sure it is properly tensioned. Someone could have put the wrong belt on or it could be badly worn. It should be 1-3/16" wide.

[Noel Woods]

Where I live, dirt daubers get into everything. From RV air conditioners to outboard water pump intakes, to atv mufflers and exhaust pipes. I had a lawn mower do the same thing with a red glowing exhaust, and upon teardown found a fist sized dirt dauber nest in the exhaust pipe.

[84td]

It seems unlikely since the exhaust seems to flow really well, when reving it will blow the leaves from the ground no problem. To be clear it glows after about 30 seconds of holding WOT.

I figured the clutch wasn't working right, the belt is new, about 1 3/16 wide, about 3/8 thick and has gear teeth like ribs on the bottom of it. When the engine is off the belt is tight, there is about 2in of space on the clutch shaft with the engine off and as soon as it starts up it sucks up to the belt. Anything I can check or adjust on it?

[fmints]

It seems unlikely since the exhaust seems to flow really well, when reving it will blow the leaves from the ground no problem. To be clear it glows after about 30 seconds of holding WOT.

I figured the clutch wasn't working right, the belt is new, about 1 3/16 wide, about 3/8 thick and has gear teeth like ribs on the bottom of it. When the engine is off the belt is tight, there is about 2in of space on the clutch shaft with the engine off and as soon as it starts up it sucks up to the belt. Anything I can check or adjust on it?

There is your problem with your belt,,,, it's too tight. If im right there should only be like an inch to an inch and a half of deflection in the belt. You can fix it by loosening the engine mounts and sliding the engine towards the Transmission to the desired tightness

[liflod]

Actually it sounds like your belt is too loose. It should engage the engine pulley very low when starting off. If it engages up on the pulley, the belt is probably too loose. Will the belt drop all the way down into the engine clutch when the engine is off? The clutch may not be fully disengaging. Engine off--- the belt should be at the bottom of the engine pulley and the top of the driven pulley.

[Tomo]

hi
The CVT belt ********must be the correct length for the application .********* The belt that was on the machine may not have been the correct belt . Did u replace the belt with a copy of what was installed ?????????
As a rough guide a good belt will sit flush with the outer secondary ,sit all the way down in the primary , approx. 1 1/2 belt slack .
When free reving the engine the the belt should travel to the outer of the primary and to the inner on the secondary .
Even when the correct belt is installed a slightly loose or tight belt will change the gear shift in a big way .
To loose
belt slip
engine loading up due to being in a to higher gear [a loose belt will ride up the pulleys quickly ]
To tight
Hard to put into gear ,transmission spinning at idle

tomo

[Tomo]

HI
The exhaust may be restricted .
If not IT IS VERY COMMON FOR VANGUARDS TO RUN LEAN
It is common to hear people saying it accelerates better with the choke ""On" .
Explanation
As a vanguard engine gets older in looses the ability to suck . The ability for the engine to create vacuum . Without the proper vacuum the carby will not deliver the correct amount of fuel .[caused by ring wear and hone cross hatch wear, it disappears.] This causes the lean condition ,particularly on acceleration .
This causes glowing red ,popping from carby and hesitation /stumble from carby

The carby was designed for a NON accelerating application [pumps,generators etc ]so it struggles with a 6x6 application .

A compression check will not show this problem .The compression release does not allow a true reading . If u do measure it a 130 psi reading is a ball park figure.This reading is deceiving
**** The only way to check for this is a leak down test ********

Check valve clearances
Popping can be caused by a ridding/slightly open valve
This leads to a burnt valve which should be diagnosed by compression and leak down test
tomo

[84td]

I took some pics, the 2in was generous, seemed like more but when I looked its more like 1/2in, I am referring to the space next to the belt. As you can see from the wear marks the belt is only going half way up the pulleys, same for the other one. The belt has 1.5in of deflection and is inbetween 1-1/8 and 1-3/16 wide at the top. Not sure if a 32nd of wear would make too much difference??
photo(8).jpgimage(1).jpg

@ Tomo, I read it could be lean or timing, it sounds like you have experience with these, I will do a compression test, I dont have a leak down tester but I did check the valves already. The intakes are .005 and the exhaust .010

Can the carb be re-jetted or drilled out for more fuel?

[ARGOJIM]

How many rpm's is it turning in neutral?

[84td]

I dont know? How do you tell?

If I had to guess I would say 3600. Sounds about the same speed a genset would run.

[84td]

Will anything bad happen if I take that dome off and look inside?

[Tomo]

Hi 84td
Operate 6x6 with choke 1/4 , 1/2 3/4 closed acceleration may improve which indicates either engine fault or fuel system
Assuming all fuel system is in good condition clean etc etc
then
Compression test
Leak down test
Find yourself a good inline spark checker with an adjustable gap .The spark can jump a huge gap ,compare each side . Fire up engine and look for a failed or failing coil/lead assembly . Check at dusk on a dark night and u may see the spark jumping out of the lead or coil
Leak down and spark checker tool are not to expensive .
After all this
Have good plugs in the engine is assumed

The main jet can be drilled out with a number drill set jets typically go up in .004 inch increment size .
As u can see some engine conditions give similar symptoms .

[Fuel system cleanliness includes lines, filter, carby ,tank verify operation/condition of carby and fuel pump . Some fuel taps and tank pickups become blocked]

I do enjoy repairing mechanical faults
tomo

ps an infared tacho is a good way of checking rpm accurately