Is this a G1? Engine Not Running Have Spark

gmforlife

New Member
I am trying to get my friends G1, so he says, running and I am diagnosing a few issues. Here's the serial number I found, if someone could tell me if this number represents a G1. Also, if I could get a year that would be great, my friend has like no paperwork on this cart.

Serial #: J10-030249

Also, engine has 120 psi of compression, which is good from what i've found right?
 

dirtysouth

Cartaholic - V.I.P. Sponsor
G1 gas. Go to www.tntgolfcar.com

They got searches you can use.
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gmforlife

New Member
nevermind, did some research and found it's a 1981. So the spark seemed week, so i purchased a new ignition coil, also bought a new fuel filter and carb base plate gasket. Going to take apart and clean the carburetor, unless it needs rebuilding. I also was looking at something down towards the crankcase, looked like maybe a Crank Position Sensor or something, but looking at some parts online found that it looks to be a STOP SWITCH ASSEMBLY. Do you think that that could be the reason the cart isn't running? My friend said that it was running great for years, then all of a sudden it just stops running. Now he is definitely not mechanically inclined at all, so for years now probably has never replaced fuel filter, cleaned the carb, spark plug, that kind of minor maintenance. But wondering about that stop switch, cause the wiring is a nightmare on this thing, splices every frickin where. Any suggestions on an easy part to replace that I might have overlooked?
 

gmforlife

New Member
Take a look at my first post, compression is listed. So I have compression which seems to be good, as far as fuel, have to get a new fuel filter, already cleaned out the carb, gotta check to make sure fuel pump is functional, but i'm assuming i'll have fuel. Spark was weak as mentioned above, so I already order a new ignition coil. If there is anything else i'm skipping that usually goes out on these things let me know.

Anyone have the stop switch assembly go out on them? When that goes bad, how do it function? does it just not allow any starting whatsoever?
 

HotRodCarts

Cartaholic
Sorry I missed the part about compression in your first post.
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You need to make sure your getting gas to the carb. The fuel pump could be bad or have dirt in it. Pull the gas line off at the carb and crank the engine over and see if the pump is working.

Check your connections for corrosion... In particular, the red wire at the key switch, the red wire at the accelerator stop switch and the red wire coming from the positive battery terminal....Check them all. If the stop switch was bad I don't think you'll have any spark at all.

I wouldn't run out and buy parts until you check the basic stuff first.

I'm not real familiar with Yamaha G1's but I'm sure someone here will chime in soon...
 

gmforlife

New Member
Yah, so I found out what the problem most likely is. So i'm checking out the fuel system, cause I do have spark, weak, but spark. I notice on the driver side wheel well that someone installed an automotive fuel pump with a regulator, so what I assume happened is that the OEM fuel pump went out. NOw after working on this thing, the only way to really get to the OEM fuel pump is to pull the motor out, so I think that someone didn't want to do that much work, so they spliced in an automotive fuel pump upstream with a regulator.

Now my friend has always mentioned that someone will work on this cart and get it running, but then after a few minutes off running it hard, it dies and doesn't run anymore. Now I mentioned my friend was not mechanically inclined, so I've put the pieces of the puzzle together. So someone gets it running, but the problem is that that fuel pump even with a regulator on it is too much fuel for this small engine, and fowls the plug, floods the engine, and doesn't allow it to run properly.

After pulling the engine and taking off the OEM fuel pump, I now realize that the aftermarket fuel pump was way too big even with the regulator for this application, too much fuel. So i've get a new fuel pump on order, new fuel line, new accelerator cable, cleaned the carb and the reeds, engine has good compression, ignition module, hopefully to get a little stronger spark, and I think she'll run good. If anyone has any other suggestions please chime in.

Oh yah, electrical is a mess, so once I get it running, redoing all of the electrical.
 

gmforlife

New Member
Will do, parts are all ordered, all coming from Florida, so it will be a week before they all get here, especially with Monday being a holiday. I will definitely give you an update when everything is running and good to go. Should be the fuel pump, everything made sense once I thought about it.
 

gmforlife

New Member
Hey guys, going to finish up the cart today, hopefully get it running. Question, what's the recommended fuel/oil ratio for these motors? I used to have a Yamaha Banshee and I ran that motor I believe at 32:1 or 16:1 as I can recall, it was a few years ago and it was a twin piston motor, but things on this cart look to be somewhat the same so I figured the fuel/oil ratio should be close to the same.
 

gmforlife

New Member
Alright fellas, got her running today. All of the new parts were installed, got all new fuel line and fuel filter hooked up, new igniter was installed and producing much more spark than the old one. So, the only problem I ran into was when i got it started, one of the coils that are fed from the generator sparked, so there must be a back feed somewhere. Does anyone know if I can get a wiring diagram anywhere, maybe someplace where I can download it and fix my problem. I am going to be re-doing all of the wiring anyway as i've said before the wiring was just a rats nest. So I just want it to run enough to tune it up, then i'm going to go in and replace one wire at a time and clean it all up.

So if someone can suggest a wiring diagram that would be greatly appreciated. As far as the backfeed, i'm sure i just have a wire on the positive terminal of the battery or something that wasn't there before, shouldn't be too big of an issue.
 

hd72m

New Member
gmforlife This is a long shot but after taking out the motor and taking off fuel pump could you have changed it without pulling motor?
Thanks
 
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