Spacers under motor bench

[DrywallDoc]

Hello everyone, my name is Roger and I am the proud owner of a (new to me) max iv. I got it on a trade and now like every first-time max owner, I have a ton of questions. Not sure of the year but I believe it's a 1998-2001. It has a Kohler command engine. Model ch680. My first question is how many washers should be under the motor bench. This one has 15 washers as spacers and seems like they are also serving as a way to move the bench higher off the transmission.if I remove them then the bench touches the top of the transmission. This engine was an upgrade from the previous owner. Also I notice that it seems alittle underpowered. Rpms go too high before it starts moving, like if it doesn't have any bottom end. The top speed is 15mph and I have read it should be around 25mph. I took the max appart to do maintenance and install EZ shift links. I'm ready to assemble the max. Would like to do it right.

[dirtdobber]

I don't know about the washer thing, but it sounds like you have a belt tension problem. First, make sure you have a good belt. Tell us what clutches you are running (or post pics of them) and someone can tell you what they are. The clutch type will indicate the belt width. The Comet 780 clutch setup, for example, requires a belt 1-3/16 in. top width. A worn belt will run too loose.

Assuming your belt is good, you then want to make sure when the engine is installed you have proper belt alignment and tension. Again referring to the Comet 780, you want belt deflection of an inch or so - just loose enough so that at idle the belt is stationary. I posted a video below of my machine (not a max). My belt may be just a bit snug, but it's tight enough that it's "ready to go" as soon as the drive clutch begins to move. In the video, it keeps spinning after I bring the machine back to idle, but I stop it by bumping the laterals.
https://www.youtube.com/watch?v=dmkUjcR-opE
The previous owner of your machine may not have gotten the tension or alignment right with the engine swap.

Andy by the way, welcome to the community!

[Toys4Me]

The engine should be more than powerful for that machine. There is normally rubber mounts under the legs. I dont remember exactly how thick they are, about 3/4"-1". I personally removed mine and run thick washers. The speed issue you are having could be a couple of different things. The engine is probably not reving to the proper RPM which is probably due to wrong spring on the governor. The other possibility is belt wear, wrong length, or wrong belt tension.

[Canadian_Zuk]

Do you have any pictures, it sounds to me like maybe your engine stand rubber mounts have been replaced with washers. There should be plenty of clearance between the engine stand and the T-20 trans. Normally there would be washers under the motor and on top of the engine stand to adjust belt deflection. If the stand is too low there would be too much slack in the belt causing the engine to rev higher before engaging.

Post some pics and let us see what your working with, hopefully its as simple as replacing the missing engine stand isolators.

[DrywallDoc]

IMG_20180213_172002.jpgIMG_20180213_172007.jpgIMG_20180213_174405.jpgIMG_20180213_174403.jpg

Here's my clutches and governor. Does the throttle assembly look right?

Do you have any pictures, it sounds to me like maybe your engine stand rubber mounts have been replaced with washers. There should be plenty of clearance between the engine stand and the T-20 trans. Normally there would be washers under the motor and on top of the engine stand to adjust belt deflection. If the stand is too low there would be too much slack in the belt causing the engine to rev higher before engaging.

Post some pics and let us see what your working with, hopefully its as simple as replacing the missing engine stand isolators.

[Canadian_Zuk]

Yes, from what I can see the assembly is as it should be. remove the air cleaner and look at the throttle plate while someone cycles the throttle lever back and forth, just make sure the throttle plate is opening all the way.

Can you post a pic of what's under the legs of the engine stand. If my machine were here I would measure the height from the frame to the top of the engine stand for you so you could find out if you were in the ball park or not.

[ARGOJIM]

That belt looks tight. You want 1" to 1-1/2" deflection.