Dune buggy was running fine yesterday. Went to start it today and take it for a spin and it started to fire up but then cut out. Tried turning it over again and again still would not start. This is unusual because it always starts right up. The engine is turning over so I know its not the battery. I noticed when trying to start it back up that the lights did not come on, nor did I hear the noise of the fuel pump kicking on when the key is turned to the on position. I immediately thought fuse so I went looking. I found a burned (or I should say a melted) 20 amp fuse behind the passenger seat below the Bosch ECU. There are four fuses in that location (three 20 amp and one 10 amp) I thought no problem, replace the the fuse and then I'm done. Nope, still will not fire up. I looked everywhere for additional fuses and/or connnections and nothing is to be found. Has this happened to anyone elses BMS 800cc EFI? I will check the spark tomorrow when I have time. I'm afraid since the lights are not coming on, I do not hear the fuel pumping making its initial noise, and the fuse was melted that it burned out the ECU - which is not good and very expensive. Is there a way to test this? Any help would be appreciated.

I'm really tired of always fixing and working on this thing. . .

What does the fuse protect? Is the fuel pump protected by that fuse? It could be a lot of things I would check the fuel pump it may be the cause of the fuse blowing. Check the fuse again and see if it is blown again you changed it and tried to start it right there is a chance it is blown again. The casue of the fuse blowing may be your problem.

I feel your pain I have not been able to locate a schematic for the EFI system for these buggies. The roketa site actually has a schematic but it is a PDF file and it is so bad you can't make out the numbers or anything. I will post a link to it maybe some of you more computer literate guys can figure out how to sharpen it up so it can be read.

I have sent emails to Roketa and LJ Tech to try and get a godd schematic I have made several phone calls as well. I did a lot of digging to find this PDF it is for the Roketa GK-40 but this system I belive is the same one they use on all the Huaihai 800cc EFI models. I could be wrong about that though. The Chinese don't give a dirty diaper about supporting their products which I think is a huge mistake on their part. They just want their money on the initial purchase. I have contacted several buggy dealers on this site also and they say they don't have the schematic either.

I have made several attempts to blow this up to read it but it pixilates real bad when I do and it, it is just not clear enough to do any good. I contacted Roketa and talked to some secretary to try and buy a hard copy of it and that went nowhere fast.

http://store.oohla.com/storefiles/termi ... 28/dlt.pdf

Mike

Check the ground at the Computer

Glade

The PDF document was scanned in from hard copy at too low a resolution. The detail is just not there to display. It was scanned in with PDF Wizard (a program from Taiwan) made by Zeon Corporation.

Mike thanks for the reply. The fuse actually never blew, it melted. The outside plastic looked like someone burned the thing in half so I'm afraid that it fried whatever is on the other end (possibly the ECU). Everything electrical has shut down with the exception of the engine turning over. No ignition lights prior to starting or even turn signals. I was hoping it was going to be an easy fix but no such luck at the moment. Its hard to find anyone with any knowledge on these buggies. I'm thinking about taking it to the local Yamaha/Suzuki dealer here in Louisville, KY and having them look at it. I really don't know.

I have a PDF file version of an owner's manual for a GK 800. On page 12 of the manual there is a circuit diagram. I cannot make heads or tails of the thing but it is better quality then yours. Not sure if it will help out. I will try to PM you and send it. I had problems putting it in this post.

Glade, Thanks for the response as well. I will look for the ground.

Did you try resetting the ECU? Disconnect battery cables, hold pos and neg cables together for at least 1 minute with ignition on. This is how the bosch and simmens ecu's are reset.

I finally had some time to thoroughly look over the problem and found it. It must have just been a coincidence that the fuse was burned up and also the buggy wouldn't start. It really did not make sense to me that the turn signals, lights, etc. would not work but the engine would turn over. I looked at every single electrical plug, connections, and fuses. I spent most of my time look in the back around the ECU. Finally I took off the ignition cover (wear the key plugs into) and noticed that one of the plug connectors was not completely together. Snapped them in and guess what? Presto. . . I turned the key and everything was back to normal. It must have gotten bumped loose and was never securely put together from factory.

I'm thankful that it was that easy and I appreciate all the advice. I'm mechanically inclined but working on more complicated engines than a simple lawn mover or four wheeler is a little more difficult. Anything else I'm good to go.

I am glad you figured it out. I was going to suggest the ignition. Had a similar problem once.