Died on the freeway??

[Scottg07]

So as the title states my bike lost power, no throttle response and died yesterday. I had finished the trans wisconsin adventure trail the day before, it had been running great on the atv trails- lots of rocks and standing water on the trails. I was riding back on the freeway 70-80 mph, 50-70 mile stretches at a time (stock seat killed my ass) when this happened. No indication of overheating or any other obvious issue. My first thought was the stator as Ive read that can be an issue. The bike restarted and I got a little further down the road, maybe a mile and died again, wouldnt restart. I got a tow home and now it fires right up. Ive only had the bike about a month, it now has 4500 miles on it, bought it with 2000, put on case guards and skid plate, uni filter, changed oil and coolant previously, as I said it was running great. Anybody have any ideas about what this could be? Thanks in advance

[cowpie]

sounds like water in the bowl maybe .. try draining it ..

[Scottg07]

MI had filled the tank with ethanol free probably 50 miles before and had run hundreds of miles since hitting mud and water holes on trails. Unless I'm missing something I don't think it could be that. Fired up today, idled fine, rode a quarter mile up the road before it died and won't restart. But it will restart again after sitting..? 

[npm]

Gas in the oil from a leaky petcock?  Vent for gas tank blocked?  

[Scottg07]

Where is the gas tank vent? Worth checking. Petcock doesn't seem to be leaking at all.

[Daleslad]

MI had filled the tank with ethanol free probably 50 miles before and had run hundreds of miles since hitting mud and water holes on trails. Unless I'm missing something I don't think it could be that. Fired up today, idled fine, rode a quarter mile up the road before it died and won't restart. But it will restart again after sitting..? 

I've had the same problem. Local garage had it for a while & could only find a coil & plug cap shorting after running it on a rolling road. They also changed the oil & checked the petcock wasn't leaking. I'm not sure they actually got to the bottom of the problem cos it has happened again but it seems ok now. Sorry i know this doesn't help but I'm interested to know what you find. I can only tell you what has happened to me with a similar problem…

[npm]

On non CA versions the cap is vented.  To check you can run it until it dies and open the cap.  If you can hear air rush in or the bike will now start the vent is plugged.  I would pull the dip stick and smell for gas in the oil and check the level. Is there spark when it first dies and won't  restart?

[Gary in NJ]

Those vacuum petcocks are a real POS and PIA - all at the same time. I'd just replace it with a Raptor unit.

npm is correct, open your oil tank and smell for fuel. Check your air filter to see if that is fuel soaked as well. When those vacuum petcocks fail they starve the engine of fuel during running and flood it over night. The extra fuel gets past the rings and into the crankcase. Suddenly the bike has a strange idle for no reason or the bike will shut down for no reason.

I didn't think it was a big deal until it happened to one of my bikes. Bike sat over the winter, started it the next spring and it just wouldn't idle. I thought it was bad fuel so I cleaned the carb and put in fresh fuel. Put it all back together and had the same poor running condition. Someone suggested I change the oil to see if there was fuel in it. I drained about a gallon of fuel/oil that day.

[Scottg07]

If you had replied yesterday I would have checked those things, but the bike is now in the shop. Pretty sure it's something with the electrical/ignition system but I will find out shortly.

[Daleslad]

Those vacuum petcocks are a real POS and PIA - all at the same time. I'd just replace it with a Raptor unit.
npm is correct, open your oil tank and smell for fuel. Check your air filter to see if that is fuel soaked as well. When those vacuum petcocks fail they starve the engine of fuel during running and flood it over night. The extra fuel gets past the rings and into the crankcase. Suddenly the bike has a strange idle for no reason or the bike will shut down for no reason.
I didn't think it was a big deal until it happened to one of my bikes. Bike sat over the winter, started it the next spring and it just wouldn't idle. I thought it was bad fuel so I cleaned the carb and put in fresh fuel. Put it all back together and had the same poor running condition. Someone suggested I change the oil to see if there was fuel in it. I drained about a gallon of fuel/oil that day.

Cheers, could you send a link for the Raptor unit please?

[Daleslad]

If you had replied yesterday I would have checked those things, but the bike is now in the shop. Pretty sure it's something with the electrical/ignition system but I will find out shortly.

I'd be really interested to learn what they find mate…

[Scottg07]

I never smelled fuel at any point and did check the dipstick, again never noticed fuel smell. This does make me want to start doing some preventive maintenance, I will look into raptor petcock. If I decide to keep it long term I'll be getting a Clark tank as well.

[Gary in NJ]

40 minutes ago, Daleslad said:

Cheers, could you send a link for the Raptor unit please?

The Yamaha part number is 5LP-24500-01-00. Be careful to get a genuine Yamaha part and not a cheap knock-off. After installing the Raptor unit you'll have to cap the vacuum line on the carb.

Edited June 6, 2017 by Gary in NJ

[Scottg07]

"We have finished checking the DRZ.  After initial checks, the stator didn't provide the level of concern that the valve clearances having closed up did.

While checking the valves, they were all found to be in spec., but the oil was gas-contaminated, so we did change the oil and filter.

Testing didn't show any faults, but the fuel level in the tank was low enough that the gas should have been in the "RES" position, but was in the "ON" position when it arrived.  We feel this may have been a big contributing factor in the behavior you described.  Don't run it as fast as it will go as the motor is wrung tight."

This was what I heard back from the shop. I havent picked the bike up yet but dont understand how this could have happened, when researching gas in oil its usually a petcock issue after a bike has been sitting. I was running high speed on the interstate when it died. Im also now concerned I may have damaged the engine running it after there was gas in the oil...

[Daleslad]

"We have finished checking the DRZ.  After initial checks, the stator didn't provide the level of concern that the valve clearances having closed up did.

While checking the valves, they were all found to be in spec., but the oil was gas-contaminated, so we did change the oil and filter.

Testing didn't show any faults, but the fuel level in the tank was low enough that the gas should have been in the "RES" position, but was in the "ON" position when it arrived.  We feel this may have been a big contributing factor in the behavior you described.  Don't run it as fast as it will go as the motor is wrung tight."

This was what I heard back from the shop. I havent picked the bike up yet but dont understand how this could have happened, when researching gas in oil its usually a petcock issue after a bike has been sitting. I was running high speed on the interstate when it died. Im also now concerned I may have damaged the engine running it after there was gas in the oil...

This is interesting as apart from the 'shorting' coil & plug cap (which I think dealt with an idling fault my bike also had) the fuel in the oil is the only other fault that was found by my garage. I worried for a while thinking that it would leave me stranded & the bike stopped again a couple of times but fired up straight away. Since then it's been ok & I just ride it without worrying. Suggest you do the same mate…

[oldmanron]

If your crank is filling with fuel the float needle and or its seat is not doing its job of shutting off the fuel supply when the float bowl is filled. Even then excess fuel should run out of the overflow tube unless it is blocked or kinked. The petcock is like the third line of defense in preventing fuel flooding. Try putting the peacock in the prime position and lay the bike on its side, this should allow fuel to flow out of the float bowl drain. If no fuel runs out it is kinked or plugged up. Either way the carb needed to come off and the float needle, seat, float level, and the float itself need to be checked out to determine the problem.

[oldmanron]

Gas in the oil is not good at all. It is a solvent, not a lubricant, and it washes oil off the bearings and other surfaces that need it and is very destructive. Don't run the bike until you know. It had clean fresh oil and that the flooding thing is solved!

[Backwoods-Bomber]

Try putting the peacock in the prime position and lay the bike on its side, this should allow fuel to flow out of the float bowl drain. If no fuel runs out it is kinked or plugged up.

The stock mikuni carb doesn't have a carb overflow line. This is why it floods the engine instead of making a puddle on the shop floor. This is extremely common on these bikes. The cause is usually two fold, the o-ring on the float needle seat fails allowing fuel to flow past the float valve assembly.

Here's what came out of my crankcase last time I had an o-ring failure.

To the op,
Don't worry about the shops statement about running it too fast, that has nothing to do with your problem. Also, the bike dies due to a rich fuel condition long before it would cause mechanical damage to internal engine components like bearings or rings.

You have two things to do to prevent this from occurring again.

1. Unplug the fuel line from carb and make sure the vacuum assembly actually stops flow when in the on or reserve position and engine not running. Replace the petcock if it flows at all.

2. Pull your carb and change the o-ring on the float needle seat with a fuel resistant vitron o-ring. The stock one is plain rubber which leads to it's failure.

[Scottg07]

So you think it was just coincidental that I had one of these issues happen while at interstate speeds? Good to know my engine should be fine. The shop didnt say anything about the petcock or the carb so it would seem the actual problem may not have been addressed yet? 

[Backwoods-Bomber]

So you think it was just coincidental that I had one of these issues happen while at interstate speeds? Good to know my engine should be fine. The shop didnt say anything about the petcock or the carb so it would seem the actual problem may not have been addressed yet? 

Yup, mine did it at 45 mph on a country back road. I wasn't sure what was up so I flipped it to prime and it restarted and I made it the two miles home. I forgot I put it on prime and by the morning all my gas was in the motor.

A shop would have to either be very familiar with drz's or actually pull the float bowl and test that the float stops fuel flow in order to figure this out. It is likely that they made your bike run by changing the oil but that the root problem is not yet fixed.