Max II no speed

[cementhead]

I have a 1980 something maxII with a 23hp vanguard in it. When I put it up on blocks and put it in gear the belt rises up on the primary and the secondary opens up and takes the belt in. The engine revs up nicely and I have 1.5 inches of deflection on the belt. When I take it out for a ride it only goes about 10mph and doesn't rev up. Any advice would be appreciated as it is driving me nuts. The t-20 is also rebuilt and I have a 94c comet clutch. Thanks, David

[jpswift1]

Does the 94C Comet clutch have the correct 4 stroke weights in it? Does your driven clutch have a 4 stroke spring in it? Also, did you remove the stock governor spring on the engine and put the correct AATV governor spring on it? If not, you can call up Recreatives and get the spring and they'll tell you how to properly set up the engine for an AATV application. It's very easy to do. Amphibious Six-Wheel Drive All-Terrain Vehicles: MaxATVs - Call 1-800-255-2511

[cementhead]

Thanks for the help. I bought the machine the way it is. Is there a way to check the weights and springs on the clutches? Can a buy a new secondary for a four stroke and if so what do you recommend. I will call ri for the govenor spring. Thanks again!

[jpswift1]

The correct 4 stroke spring in the driven clutch should have some green or red paint on it. It probably has worn off over the years, but some of the color may still be visible. You can buy a new secondary/driven clutch spring from Recreatives as well. They have red, which gives you a little more low end torque and green. Either one will work great with a big 23HP Vanguard. I'm going to assume the Comet drive clutch you have is a 4 stroke clutch since it's most likely mounted on a keyed shaft because the Comet Duster clutches that are for 2 strokes are used on tapered snowmobile engine shafts.

[cementhead]

Thanks jpswift1 for the info. I am going to call ri tomorrow and order the red spring clutch. My machine came with extra parts including a slide throttle. I hooked it up and got it up to 31mph, but it is a little slow from the start and then picks up very well. It is a little hard to drive with the throttle behind me, but I love it. Thanks again for the help.

[amphibious drew]

One other thing is to bend the tab on the govoner spring.

[jpswift1]

You should probably order the correct throttle cable and handle too while you're at it.

[Joe H]

Cementhead already said that everything works properly when it is up on jack stands or "no load" what makes you guys think that the clutching or the governer would change when he puts it on the ground or "load"?

[amphibious drew]

Cementhead already said that everything works properly when it is up on jack stands or "no load" what makes you guys think that the clutching or the governer would change when he puts it on the ground or "load"?

Idk Joe, but since you mentioned it, did you check the valves, Briggs will run pretty good a single cylinder without load, but when under load not as well. They also don't hold adjustment well and float valves. I would check that before ordering parts, but a few springs are cheap

[Bazooo guy]

I hooked it up and got it up to 31mph, but it is a little slow from the start and then picks up very well.

The clutches are designed to stay in low gear and allow the engine to rev higher untill you get to speed.
You should feel it shift into high when you get moving on level ground.
The different springs will change the shift point.

[jpswift1]

When many people do a 4 stroke swap on an older machine they'll usually leave the old driven clutch spring in. Also, Recreatives sets all their Maxes up with a different governor spring and like Drew said, they put a slight bend the tab that the governor spring hooks to. All these little details need to be looked at, because it's not just put a 4 stroke in and go like many people do.

[Joe H]

I don't know JP, I have done a few Four stroke swaps and never had any problems with leaving the old yellow spring in the secondary, I plow snow, run tracks, pull my utility trailer with 115 bales of hay- no problems and it is only a 16 hp briggs, and I believe the governer spring change is so the hand throttle isn't hard to pull so any should work. I agree with Drew and would check the engine out before I spent a lot of money on other stuff.

[amphibious drew]

I don't know JP, I have done a few Four stroke swaps and never had any problems with leaving the old yellow spring in the secondary, I plow snow, run tracks, pull my utility trailer with 115 bales of hay- no problems and it is only a 16 hp briggs, and I believe the governer spring change is so the hand throttle isn't hard to pull so any should work. I agree with Drew and would check the engine out before I spent a lot of money on other stuff.

The only problem I have with the valves being the issue is that he achieved 31 mph with the other throttle set up. I don't think you would get that kind of speed out of it with a valve issue unless maybe the old yellow spring just kept allowing the engine to build momentum without bogging it down like a green or red spring would do. I also thought the governor spring helps set the top end rpm. It could be that you need a valve adjustment as well as a secondary and governor spring to get the most out of your engine.

[egoperf]

when I did my 2 stroke to 4 stoke conversion I tried it with the stock spring it was fast but had no power, I put the red spring in it and it worked great

[Joe H]

I don't think it is a valve issue, and the governer is adjusted by bending the tab, and as far as the secondary springs go, if you aren't running oversize tires or do something else to change the final gearing the stock spring should be fine unless it is worn out. Bottom line is if the clutches and governer fuction on the jack stands it should work on the ground maybe not optimal but should work and do more than 10 mph. Sounds like the engine is loosing power under load.