Engine cutting out.??

[kalbo]

Well, I thought I had solved the 'cutting out' problem. After cleaning all the electrics, I have ridden the bike for the last three days and clocked up 250 trouble free miles. Then this afternoon, without warning it cut out again. There was a loss of power, as though it was running out of fuel, then it shut down. I was able to restart it, but it happened again and again. Seven times in less than a mile. I was just about able to get it home with my wifes' Valentines flowers! I made myself a coffee and then took it out again. It ran perfectly. I ran about 30 miles without a problem. I now know it isn't the fuel, or the carbs, or the Coils, or any of the electrical connections....so what's left? Could it possibly be the fuel pump? The pump seems to work fine, I hear it click a couple of times when I turn on the ignition. Could the fuel pump have an intermittent fault ? Could it be the fuel pump relay? Could a faulty relay cause it shut off the fuel? It didn't just die instantly, as though it was a kill switch problem....It was as though it was running out of fuel? 99% of the time it runs perfectly. This could be a serious danger if it happens whilst overtaking.

 

[Bill Seward]

Has to be a fuel delivery problem, in my opinion. I put a new pump in my '85 last year it was failing, and cutting out intermittently.. Lots of them available on EBay for less than $20...

Do the early Maxes even have a fuel pump relay? No idea..

 

[davesax36]

Can you get it to die on the center stand? Try that and watch the fuel filter to see when the pump is running.

 

[Traumahawk]

Check the connection that goes to the fuel pump, also might be the switch...put the switch on RES, and then see if it cuts out anymore.

 

[Jan Bee]

http://www.ebay.com/itm/302038722623?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

 

[kalbo]

The problem is finally solved !!
It WAS a fuel delivery problem. The bike was cutting out because I was using more fuel than the fuel pump was able to deliver to the carbs. As soon as the carbs ran dry, the bike would cut out, as if running out of fuel. It was either a defective fuel pump relay, or a defective fuel pump? I went to see my mechanic this morning about ordering replacement parts. He just happened to have an identical fuel pump relay in his shop, so we decided to try that first. We swapped out the relay and started the bike. Immediately, I could hear a constant 'tick, tick, tick' from the fuel pump. This is something I had never heard before. It appears that my relay was the problem and as a result the fuel pump has not been working and the carbs had not been receiving fuel at the required amount. It was OK at low speed/low revs, but once I increased the power, the carbs would drain faster than they were being refilled, hence it would cut out. After a short while, it would restart as the carbs had refilled. Now that I have replaced the relay, it is running great. More Power and more responsive and no more cutting out.
For information, the fuel pump relay is found on the left side under the scoop cover. The 1st (far left) is the fuel pump relay, the 2nd is the flasher relay and the third is the Vboost controller. Thanks to everbody that contributed to helping me solve this problem.