Goat won't do over 30, help me!

[Aussiecowboy]

So after a number of weeks of stripping and rebuilding hubs and driveshafts, I finally got all the hubs back together last night. I couldn't resist bolting the brake drums on (no brake assemblies fitted) and going for a quick drive. I live in a rural area so there is really nothing to hit, and the handbrake works well.

Anyway, I can't get the goat to wind up over 30mph, she seems to be just lacking the power to get there. The engine starts easily and idles nicely, it will sit and rev to the govenor ok but is just gutless. It's worth mentioning that it had been sitting for 10 years before I got it.

I have changed the fuel filters and put a good quality injector cleaner through it, air cleaner is good and the mesh between the air cleaner and blower is clear. At abut 20mph I slipped it into neutral and she coasted a good 100 yards before stopping so it's not part of the driveline dragging and it is definitely in 2 wheel drive and high range.

I'd be mighty grateful for any advice or suggestions on what to try from here.

 

[JR Scout]

Had the same symptoms after rescuing one that had not run for a few years, and did the same treatment (filters+ additives) which helped a good bit. In dealing with other farm equipment, I have seen that it may take an extra cycle or two with filters to really clear out the water. I have also read elsewhere on this site that resetting the fuel rails would be the next logical step, but haven't had the extra bucks (or pounds, as the case may be) to spend on that.

 

[dmetalmiki]

Also check the supercharger, If that is not functioning correctly, then you will have no power. (symptoms).

 

[Impressus]

I too am having power problem. my top speed was 35 mph on a slight downhill incline. This evening I changed out the filters, the primary filter had a quarter of a cup (at least) of garbage, looked like leaves to sand to smaller. the secondary filter had a leaf in it. I had to go try it out and I got up to 47 mph and the same incline, 30mph coming back up it. Air filter is next, someone revamped the intake down to the blower, so might have some issues down there so that's next for me. Isn't there a air shut off flap there too? My brother said his next move would be adjusting the fuel rails. I read somewhere that there could be a buildup of carbon coming out of the exhaust that could restrict the outflow..........sounds like a bit much but that's what I read so I might take a peak at that at some point in time if all else fails. Lastly I was told that the 353's were gutless and not to expect any more than that, but then he wasn't a fan of them.

 

[BillIdaho]

I get about 55 to almost 65 mph on the interstate. The one time I did notice it wouldn't get up above 40 I changed the fuel filters, and it fixed the problem.

(And far be it from me to judge, but driving it anywhere with no brakes is--to be very polite-----not the wisest thing a guy could do. There are too many variables to consider, and countless variables you haven't considered. Don't rely on the parking brake if you are going more than about 1 mph. I saw a guy slowing down approaching where he wanted to ultimately stop and instead of stepping the brakes, he pulled up on the parking brake. Something made a loud pop, and no more parking brake. It isn't made to be used as an emergency brake, it is for keeping it stationary when parked.)

Please don't be hatin'. I just have to say there aren't enough goats and goat-lovers to spare. Brakes are pretty well towards the top of the must-have list if it is going to move.

 

[Aussiecowboy]

I get about 55 to almost 65 mph on the interstate. The one time I did notice it wouldn't get up above 40 I changed the fuel filters, and it fixed the problem.

(And far be it from me to judge, but driving it anywhere with no brakes is--to be very polite-----not the wisest thing a guy could do. There are too many variables to consider, and countless variables you haven't considered. Don't rely on the parking brake if you are going more than about 1 mph. I saw a guy slowing down approaching where he wanted to ultimately stop and instead of stepping the brakes, he pulled up on the parking brake. Something made a loud pop, and no more parking brake. It isn't made to be used as an emergency brake, it is for keeping it stationary when parked.)

Please don't be hatin'. I just have to say there aren't enough goats and goat-lovers to spare. Brakes are pretty well towards the top of the must-have list if it is going to move.

I'm curious as to what you think I haven't considered. You haven't seen the scenario, dead flat, straight road about 3 miles long, a good mile of visibility all round, no traffic, no side roads, no trees, absolutely nothing to hit. I idled it there at about 2-3 mph. I wasn't suggesting I drive on the parking brake, merely suggested it was there as an option if needed in an emergency. I'm not advocating driving without brakes either, I did a limited road test under very controlled conditions, nothing more.

 

[Gamagoat1]

Check for dragging breaks. Unless they are adjusted by the book the least amount of drag will slow you down. You dont have much HP to start with. Shoes should not be touching the drum at all!!

I too am having power problem. my top speed was 35 mph on a slight downhill incline. This evening I changed out the filters, the primary filter had a quarter of a cup (at least) of garbage, looked like leaves to sand to smaller. the secondary filter had a leaf in it. I had to go try it out and I got up to 47 mph and the same incline, 30mph coming back up it. Air filter is next, someone revamped the intake down to the blower, so might have some issues down there so that's next for me. Isn't there a air shut off flap there too? My brother said his next move would be adjusting the fuel rails. I read somewhere that there could be a buildup of carbon coming out of the exhaust that could restrict the outflow..........sounds like a bit much but that's what I read so I might take a peak at that at some point in time if all else fails. Lastly I was told that the 353's were gutless and not to expect any more than that, but then he wasn't a fan of them.

 

[dmetalmiki]

Re - reading this thread, I will point out that apart from the 530C our goat IS the fastest vehicle in our collection.

No air leaks, GOOD supercharger and settings. ALL new filters, (air and fuel).

 

[Gamagoat1]

I wish it was supercharged. The Goat has a blower to supply air for ignition, thats all.
Have talkked to guys that wanted to change the gearing for the blower to get a little more air for high altitude.

Re - reading this thread, I will point out that apart from the 530C our goat IS the fastest vehicle in our collection.

No air leaks, GOOD supercharger and settings. ALL new filters, (air and fuel).

 

[Aussiecowboy]

I have since sorted the problem, it was a combination of a number of things. Sludge in the bottom of the tanks was blocking filters, questionable quality diesel, throttle linkage and cut-off cable adjusted poorly, it's a much happier unit now although I did find out my transfer case is trashed.

 

[combat32]

Any luck on your t case yet?

I couldn't have resisted driving it either and I am also almost ready to test drive mine a bit.

 

[Aussiecowboy]

There is a new transfer case on its way to me now. Happy days.

 

[Jericho]

Hey Gamma goat one, I clearly remember being told the same thing at a training class on Goat engines in the mid eighties, I remember an AF FTD instructor lecturing that the real purpose of the supercharger was to assist in exhaust cycle scavenge , *( which apparently was found lacking ). ALTHOUGH . he did add a caveot. He speculated that at speed one could hear a whine of howl in the supercharger , and postulated that at that point it was generating intake compressed volumes of air to give a small bump in power. , Hadnt tought about is since until I saw your post .

 

[cb88]

Jericho, acutally I'm restoring a gama goat engine and have done a lot of reading about Detroit 2 strokes. The blower is necessary to push air through at startup, but becomes parasitic when running at full power. There is a youtube video of someone putting a whipple supercharger on a 6v53 but it didn't work well as I understand it. They ended up swapping for a smaller blower plus turbochargers and bypass vales on the blowers for when operating with turbo pressure high enough that the blowers become parasitic. In short blowers don't typically push enough air through at high RPM whereas a turbo can.

 

[Gamagoat1]

They work well enough to supply the air needed and designed . The two stroke can't work with out something to supply air either a blower,(Gear driven) or a super charger, (exhaust gas driven.) The blowernever becomes parasitic, the faster the engine runs
the more air it needs, the only place it can get it is thru the blower.

Jericho, acutally I'm restoring a gama goat engine and have done a lot of reading about Detroit 2 strokes. The blower is necessary to push air through at startup, but becomes parasitic when running at full power. There is a youtube video of someone putting a whipple supercharger on a 6v53 but it didn't work well as I understand it. They ended up swapping for a smaller blower plus turbochargers and bypass vales on the blowers for when operating with turbo pressure high enough that the blowers become parasitic. In short blowers don't typically push enough air through at high RPM whereas a turbo can.

 

[Jericho]

Iam sure one could volumetricly map it easily these days but 59 to 70 , not sure they would have spent the money if the ARMY hadn't asked for it and offered to pay

 

[Impressus]

Did anyone figure out what to get more speed out of a goat. I mentioned some months ago that I could only get 47 tops out of mine. My whole project got put on hold but now I'm back at it and trying to push things up to 55 or 60 if I can. As a quicky about engine, it fires right up when the temp is in the 50's. In high range 1st, 2nd and 3rd gear I can bring it up to speed, but when I shift into high, its screaming like crazy but I can't get the speed I need. In the mean time I have a question about my pre-heater or flame heater.....it isn't working. What I need to know is how does this system work. When the air pump is activated what is the sequence of events after that? If anyone could describe this or point me in the right direction I would really appreciate it.

 

[m38inmaine]

http://www.steelsoldiers.com/upload/gamagoat/tm9-2320-242-20.pdf

Page 2-116, paragraph 2-45

 

[Hummermark]

The 6-71 detroits in the m10 6046 twin pack,the supercharger always made positive pressure from 0.3 psi at 400 rpm to 8 psi at 2100 measured when I dynoed them.

 

[Impressus]

thanks. I got my preheater working. My blower motor was locked up and the pump part was full of dirt, cleaned and oiled things up, put it back together. When I went to try to start it at 30 degrees it wouldn't even pop off, hit the preheater and it's instant start. thanks again. As an after thought how often and how much oil should one put into the air compressor? there is an oil hole there in the plastic shroud.