Duromax 16 hp into a late 80's Marathon

nhoffman94

Hey Everybody, i recently picked up a 1987 ez-go marathon in rough shape. it has a rotax 400 fan cooled twin cylinder in it right now with about 35 hp. it is really fast, but it is a pain to maintain and move around, its way to loud since i live in the city, and there no reverse or electirc start. I picked up a 80's or 90's club car rear end with forward and reverse, the shift linkage clucth, pulley, and brake that i will be swapping in. I will then buy a Duromax 16 hp electric start off ebay to swap in once the axle is done. i am going to lift it and put 22 inch offroad tires on it as well, i want to use it to trail ride, run around the neighborhood, travel down some old railroad trails in wisconsin in michigan in summer, and off road. i also plan to build a cab, and a snow plow. Any advice or thoughts would be appreciated. this will be a trail/utility machine

BGW

__________________
This advertising will not be shown in this way to registered members.
Register your free account today and become a member on Buggies Gone Wild Golf Cart Forum

sho305

Watch what CC rear you get some run backwards that could be an issue. If you want it quiet you might find a larger lawn muffler but a cheap small normal car muffler will be cheapest and quietest far as I know...more like a stock cart yet still flow more air. Should not have any spark issues with those either. The 16hp has good torque for putting around I put one in a G9 last summer doing another this spring, with stock yami clutches. I don't know about using the smaller 1" belt clutches some carts have I forget what ones....find out if it will work. I also put a car airbox on this one it was $10 at a little boneyard, 10 more for a muffler lol. Then I piped it to the front with 2" pvc to avoid dust we have lots of that. Find out the offset and distance of the clutches so you can duplicate it or you will have to find a different length belt.

Far as the engine I took the governor out of it. It runs exactly like the stock engine same top speed sounds similar but has lots more torque at low/mid speeds, like double. So this next one I am planning on decking the head, advancing the timing, porting a little, maybe different carb in an effort to get a little more rpm thus more speed. Can't do much with them and you need an expensive aftermarket flywheel then you can put cams and all that in them. All that stuff is up to you of course, just saying some of it you can prepare for ahead of time I spent time chasing down parts to put this stock one in.

You need to hook the fuel pump someplace you make or buy an intake spacer with a pulse fitting. Otherwise look at AGK's site and it tells on there how to pulse a 6.5hp that is similar, but you can't use the valvecover on the 16s I have seen they are not like the 6.5. You can't use the governor shaft hole I tried that it is full of oil.

thewskrs

I just saw today that carolstream on ebay has his 16HP engines now with the 3 amp charging system. $399. Free shipping. I love my Duromax, but they are the same LIfan engine. But the latest offering from Maxtool doesn't have the charging system. I hauled off tree tops and even dragged off 8 foot sections of tree trunks with the 16hp the other day. Hard working little cart for sure.

nhoffman94

Thanks for the help!
Yeah, my club car rear end is a reverse runing one i believe, but the input is alos on the opposite side of most normal turning ones. all i need to do to make it all work is rotate the motor so that the shaft comes out on the passenger side, which is where the pully is on the axle, that mean it will also be running in the correct direction in order to still runn the reversed club car rear end.

nhoffman94

thats awesome, just saw your reply now, ill defintiyl be doing hauling with this, the 16 horse looks great and is at an unbeatable price, i hope they will be reliable though.

sho305

The one I put in is a carolstream, it was 380 tmd last year, 3A electric start, but we left the generator in and start with it too. He said he gives a discount if you call on the phone I dunno. They went down maybe are going back up now I saw them cheaper last month. The aircleaner is crappy otherwise all good and only heard of one sticking a rod so far. HF sent me a coupon for $89 for a 6.5 hp. I have to order mine pretty soon likely will get a CS 16hp again. Of course where I am it showed up the next day lol. I was impressed not that close that I wanted to drive there.

nhoffman94

thanks for all the input, i actually just found and bought a brand new, well its 6 years old, but has less than an hour of run time, 14hp briggs vanguard V-twin. I bought it on ebay for 409 dollars plus 72 shipping. I dont know if i mentioned this, but google pays me for youtube videos and i just sold enough phones to pay for this one, i think for the extra 200 dollars it is worth it, i know it is only a 14hp, but its a v tiwn, so the torque should be better. any thoughts or opinions would be appreciated.

sho305

Find out if you can get a rev kit to fit it, it will still have a nice top speed then. I ran equipment with those, they run really nice. I just put a clone 16 in that is more likely a 15 real hp. It has great power spins up hills compared to stock cart, so I think it will work fine.

nhoffman94

ok, so you do think the v twin will be fine, thats good. im sure it will have better torque as it is a twin and the vanguards are top notch. it was meant for a generator, which broke brand new, the the engien has been sitting in storage. the cranks has been machine to be 1 inch OD with a 1/4" keyway, which is also nice

sho305

You should be all set, just get a clutch and start dropping it in. I need to order a clone soon here weather just too cold yet.