[TJE]

Hi lads,

I have a really annoying problem, the bike cuts out when driving, typically above 60km/h ...

I then pull the clutch and try to keep the engine alive with a little throttle back and forth, and usually the problem goes away, but returns again shortly after.

The other day, it did it even at low speeds, and I had to limp back the last 30 nerve wrecking km of a drive.

The bike runs really well besides this ...

I'm off to the mechanic tomorrow. Any ideas as to whats causing this? My gut says electric problems ...

I should add that I've checked the R/R and its fine, and my sidestand switch has been nutered.

Thanks!

/Thomas

 

[spencer54]

Sidestand switch would have been my first guess, so I would get a meter and check your coils and generator/pick up coil.

 

[Sohoeasy]

Hi Thomas, If the problem is going away by clutching and throttling I'd say it's more likely a fuelling problem than electrical. You could try draining the carbs first just to see if it clears any blockage/sh*t.

I had a major blockage a couple of weeks back which kept making the motor die. The way I actually cured it was purely by chance. Determined to get to the workshop, I just held it in first gear to stop it stalling and after several miles whatever was in there blew through the system and the bike surged back into life.No problems since. I hope it is something as simple as this for you too ?

Otherwise let us know.

 

[Lord Vader]

making the motor dye.

Oh cool,what colour :toothy10:

 

[AlanH]

How's the fuel pump?

 

[BobA]

My first thoughts are the fuel pump (not being able to keep up with demand or having an intermittent fault or connection), or a possibly a bad tank of fuel, or blocked breather to the tank. Also worth checking the air filter.

Fuel pumps are a well documented weakness (although having had 8 Africa Twins, I've never had one fail). You should be able to check the clear fuel filter and see the pump pulsing fuel through it while the engine is idling. The fuel pump ONLY works when the engine is running, as it takes a pulse from the CDI to trigger the contact breakers inside the fuel pump (which is the part of the pump that fails).

Get a length of wood that will reach the fuel pump (and carry it on your rides) to enable you to give it a gentle but sharp whack with a hammer. Next time the bike starts playing up, give the pump a good clout to see if it clears the problem.



Good Luck




Bob :thumbup:

 

[TJE]

Many thanks everyone ... I went through most of the stuff I could think of, and the mechanic also had a look. The fuelpump is a new Facet, and all the hoses looked ok, so my initial thought was either dirty carbs, allthough they had been cleaned 3-4 months ago, or electrical.

It proved to be the 30 amp main fuse, on the left side of the battery, that was melted. A few days before, I had the red socket there replaced, as it was fried.

I saw somewhere on the forum, that someone removed this lump of molten plastic entirely, and soldered all the wires, and placed a seperate 1 fuse fusebox. I've replaced it 3 times already, and I think the heat here plays a big role. Anyone remember this thread, by the way?

Only testet the bike on a quick spin, but I need to go for a longer ride, to make sure.

I really love this bike, but I'm spending too much time fixing it. A guy here is selling his smoothrunning twin, so I may just make a switch ...

Thanks again! Much appreciated ...

 

[spencer54]

You need to find out why the fuse is melting is the rectifier outputting too much juice or is it close to a heat source?

 

[AlanH]

You need to find out why the fuse is melting is the rectifier outputting too much juice or is it close to a heat source?

...or maybe it's just that there isn't a good connection and, due to the resistance, it's generating heat.

 

[TJE]

You're right, I need to find out why ... I know it's fairly common for the big red socket next to it to melt, but I've never heard of trouble with this fuse. It should be said that the fuses down here look rather flimsy compared to the originals, which could lead to a bad connection, as Alan said.

The rectifier should be good, as I changed it 6 months ago.

For now I'm just keeping a close eye on the fuse and the red socket. Not sure what else to do?

Thanks again!

 

[Faceplant]

[The fuel pump ONLY works when the engine is running, as it takes a pulse from the CDI to trigger the contact breakers inside the fuel pump (which is the part of the pump that fails).]

I'm confused! Should the motor be running to check the relay that controls power to the pump?
The Haynes manual is a little vague in this regard

 

[Thomas Happ]

Just an idea: check the connection from alternator to rectifier. Mine looked pretty bad ...

 

[gcsixty6]

You're right, I need to find out why ... I know it's fairly common for the big red socket next to it to melt, but I've never heard of trouble with this fuse. It should be said that the fuses down here look rather flimsy compared to the originals, which could lead to a bad connection, as Alan said.

The rectifier should be good, as I changed it 6 months ago.

For now I'm just keeping a close eye on the fuse and the red socket. Not sure what else to do?

Thanks again!

We're talking about an RD03, right? In any case you can exclude the Facet just filling up your tank. If the problem reoccurs it is not the pump. The second problem AT give is usually about R/R. They tend to break and give HUGE problems. Buy yourself a MOSFET model and you forget also them. Given the melted part I would think that is, or was, the original issue, as u have already changed the r/r, right?
But really consider a Mosfet. They are bulletproof.
If it is a RD03 cdi-s can also start bitching but usually they hide a different electrical problem.
Again, usually fuel pump and r/r are the main issues that may manifest in strange different ways.

 

[TJE]

Just an idea: check the connection from alternator to rectifier. Mine looked pretty bad ...
View attachment 165827

We're talking about an RD03, right? In any case you can exclude the Facet just filling up your tank. If the problem reoccurs it is not the pump. The second problem AT give is usually about R/R. They tend to break and give HUGE problems. Buy yourself a MOSFET model and you forget also them. Given the melted part I would think that is, or was, the original issue, as u have already changed the r/r, right?
But really consider a Mosfet. They are bulletproof.
If it is a RD03 cdi-s can also start bitching but usually they hide a different electrical problem.
Again, usually fuel pump and r/r are the main issues that may manifest in strange different ways.

Thanks guys! The post is from 2012, though ... It's an RD07a. Since then I installed a MOSFET R/R and soldered the wired to the alternator. I also bypassed the 30A main fuse by installing an external fuse to prevent the fuse and red cap from melting due to bad connection. Recently I've had more electrical problems, first it was one of the connectors (ignition) behind the tripmaster that had a poor connection and was half melted. A few weeks ago, the bike cut out randomly due to another bad connection in one of the sockets under the airfilter. One more problem discovered today, was the 10A fuse for starter, ignition and fuel rattling in it's socket. I tried to bend the curved pressure thingie to get a better grip on the fuse leg, but it broke off. Installed an external fuse instead. Wont have to worry about that again, I hope. Bike still starts and dies after sorting this, so I think it's due to clogged carbs from standing 1,5 years with some very old fuel in. I emptied the tank and it looked like tea Here's a comparison to fresh fuel

 

[gcsixty6]

Ah ok, I have seen the bad contacts... while you have the tank dismounted I would suggest to clean the carbs (and check valve clearance). It is an easy operation and that you guarantee your engine gets the right mix. But I am sure I do not have to tell you that.

 

[TJE]

Here's an update: I was fooled a few times, when the bike started up and ran fantastic a few minutes, and then would die. This made me think that it could only use the fuel in the carbs, and not get new fuel, so I had a look at the fuel pump (Facet) Problem is that I can't remember how easy it is to tell if it's running, and I couldn't really feel anything while cranking, so tonight I will do some measurements on it, and see if it's a wiring problem or if the pump is shot.

I've never heard of a Facet pump fail? And considering the relatively few KM's I put on it, I would be quite surprised if that was the case.

I'll update after having scrutinized the bike once more.

 

[HAT Rider]

You should hear and feel the pump pulsing.

 

[TJE]

UPDATE:

I bypassed the pump with a piece of hose, filled the tank, and guess what? It still dies after running great for some minutes. GRRRRRRR!!!!!!! After running great, the idle gets lower and lower, and it starts sounding like a lawnmover, and after a while longer, it sounds like it's just running on one cylinder, very rough.

My new theory is that either it's sticky float bowl(s) (will check if there is gas coming out of the bowl drains after the bike cuts out) or it's something that fails when it gets warm. Other than that, my only remaining idea is the CDI that could be about to fail ...

Anyone has any ideas on what else I can do next?

 

[Lensman]

Fuel filter and tank tap both working OK?

 

[HAT Rider]

It still sounds like a fuel problem. How long does it take to start to run rough and then cut out? Perhaps worth trying to simulate it running out of fuel so you control this to see if the symptoms are the same? If it takes 10 minutes for example, you could starve it of fuel after say 5 minutes and see what happens. If it runs rough and cuts out in the same way then it looks like fuel but if its different then perhaps something else.