Bringing Max IV back to life- lack of power issue

[Smurfwarrior]

I purchased a Max IV about a week ago and have been working hard to get it back running well. The previous owner let it sit a year and I've done the following- Removed and replaced fuel with ethanol free fuel, put seafoam in the fuel, replaced the fuel filter, replaced both plugs, replaced the fuel pump, cleaned the interior of the carburetor (it had yellowish film on the bottom), adjusted the idle and tightened the chains. The clutch belt looks like it working fine, climbs to the top of the top wheel and moves into a tighter radius when the upper moves to a larger radius.

Here's the issue, on flat ground the power is fine, goes about as fast as I'd like it to but as soon as I hit a slight incline (and I hit a ton of those short very steep hills where I hunt) it bogs down and will sometimes die if I don't apply a little choke, and sometimes it dies anyway. It slows to a crawl, I could walk faster that this can get up those hills. I have the B&S Vanguard 18hp engine in it. Am I expecting too much from this? Should I be able to power up hills or is this normal behavior? Any hints as to what to try next would be greatly appreciated.

[garrett1308]

Needing to apply choke points to a fuel problem. Take the jet(s) out of your carb and clean it, blow some carb cleaner through all the holes in the carb.

[Smurfwarrior]

I did all of that when I cleaned out the carb today, no change in lack of power.

[Smurfwarrior]

Here's a thought I had, the fuel line comes out of the body where the upper and lower body meet, the fuel line is long and hangs down almost to the bottom where the fuel filter is located, then the fuel line climbs up a couple feet to where the fuel pump is located. It that too much distance uphill for the standard pump to pump?

[garrett1308]

What kind of motor do you have, and what fuel pump? I doubt that your pump is having issues, or youd be having more trouble than just climbing hills. Are your clutches working?

[Smurfwarrior]

B&S Vanguard 18hp. Fuel pump is a brand new B&S one. As far as the clutches working properly, They seem to be, but hard for me to tell as I'm not sure what to look for other then the band expanding and contracting with throttle applied. Would increasing the tightness make sense? It seemed tight when I checked it, but it could be tightened. If that is the suggestion, please let me know how to tighten it as all I've seen is to shim the engine to increase the distance, and I guess that's the only way right?

[garrett1308]

If you see the primary clutch close in on the belt, and the secondary open up, then it's working. We'll assume it's got the right belt length and tension. Re clean your carb, its easy, won't hurt, and could well be your problem. Currently, can you run the machine at WOT on a reasonably flat surface? Does choking the motor at WOT help or hurt? It'll be an odd situation if it only happens at the base of a hill.