2014 CRF450 with fuel in engine oil

Help needed, I have seen various threads relating to this problem on the 13 model but I am experiencing this on my 14. Have ridden the bike hard, easy, idled without touching the throttle but all to no avail.

Any help really would be appreciated. ROSS

Help needed, I have seen various threads relating to this problem on the 13 model but I am experiencing this on my 14. Have ridden the bike hard, easy, idled without touching the throttle but all to no avail.

Any help really would be appreciated. ROSS

Stuck injector.

I have noticed this on several fuel injected bikes. I don't realy have an 100% awnser. I do not think it's a stuck injector, more like bliping the throttle when shut down and still having a ellectrical charge before dying off. It.s more noticable on Honda than other's becuase of the seperate oil, and less to polute.

Edited by BRX-WRX

Thanks for the replies, I was concerned that I was not letting the bike warm up enough, but yesterday I let it idle for 5 minutes on two ocasions and both times the oil level increased. I'm thinking that it could be the injector, but I really cannot be sure.

Idling for 5min is waaaaay too long.

+1

Idling for 5 min is too long. Its not the cause, but its a super bad idea. Residual pressure in the fuel line after you shut it off is pushing past the injector, Its not stuck, it just doesnt seal off 100%. Some guys have taken to putting a switch in the fuel pump line and turning the fuel pump off and letting the engine die that way instead of backing up 45 psi on the injector. The check valve in the pump/tank is better than the injector.

This has been happening on my 2010 250f forever. I routinely  now change the oil every other ride. I even talked to honda about it.The guy is aware of the problem but since there is no fix to date Honda won't admit it or issue a recall. Change your oil alot. I always put in 22 oz. in my 250 then measure what I take out. So far there is no real noticeable difference in volume but the oil is thinner and smells of gas. 

The fuel cannot get into the oil while the engine is running. It must drip into the cylinder and past the ring while sitting. However, I would think there would be some smoke or starting issues. There must be a vapor management system like cars have. Maybe the fuel is getting into the engine through this system. Its hard to believe an injector is more problematic than a carb. I've had plenty of leaky carbs. Just a thought.

Thanks for the relpies guys. Just to update; When idling both times the oil level increased. I had drained the oil before and let the bike sit for  a week to see if any gas collected in the crankcase, but there was none.

 

Yesterday the injector was removed and pressure tested, all was fine. My next step is to run injector cleaner in the gas to make sure that the injector is 100% clean.

 

My thoughts, however, are that this is due to the temperature of the engine as have seen on other threads, either there is a faulty temperature sensor, and so the engine is being fed way more fuel than necessary, or the EFI is set-up to be super rich as low rpms.

 

Really appreciate your help, I will update after more tests this weekend.

Edited by Ross R

Your bike would be running like complete crap and would smoke if the injector was spraying enough fuel to flood the crankcase. If the fuel is getting in past the rings, there will have to a point that it doesn't run good. The oil level will raise slightly when warm, but it should go back down when cool. I would look at the fuel tank vent system. Is there a vacuum fuel pressure regulator like a car? I couldn't find any info online in a quick search for a system diagram. If its running perfect, I'd just change the oil and ride.

What are the average ambient riding temperatures for you?

Pomoco - yes it runs fine, will look into the tank ventilation. The oil does rise slightly when warm, but gas is definitely getting in.

 

Eddie8v - the bike has been run in approx 10 - 20ºC so far.

 

Thanks for the help.

Ross

Voltage to the injector shouldn't be a problem.  Even though the capacitor may hold voltage after you shut off the engine, once the crankshaft stops moving, there is no rotation signal to the ECU, so it stops sending a on/off ground signal to the injector.  Based on history, it's probably the pinnacle in the injector not sealing off very well after shutdown.  Also all engines have blow by past the rings to some extent, and if it's running rich, it fill the crankcase with excessive hydrocarbons.  And it doesn't have to run so rich that it's blowing black some either.  

 

If it's the injector leaking down after shut off, you should be able to pull the injector and watch for dripping.

Pintle...

Voltage to the injector shouldn't be a problem. Even though the capacitor may hold voltage after you shut off the engine, once the crankshaft stops moving, there is no rotation signal to the ECU, so it stops sending a on/off ground signal to the injector. Based on history, it's probably the pinnacle in the injector not sealing off very well after shutdown. Also all engines have blow by past the rings to some extent, and if it's running rich, it fill the crankcase with excessive hydrocarbons. And it doesn't have to run so rich that it's blowing black some either. If it's the injector leaking down after shut off, you should be able to pull the injector and watch for dripping.
Edited by Eddie8v

Pomoco - yes it runs fine, will look into the tank ventilation. The oil does rise slightly when warm, but gas is definitely getting in.

Eddie8v - the bike has been run in approx 10 - 20ºC so far.

Thanks for the help.

Ross

As stated, you can/will smell fuel in the oil on a rich-running engine, but the oil level shouldn't raise a significant amount. You could have ring-sealing issues, but I would look into the stuck pintle/leaking injector. Be sure to warm/idle the bike for 2min at least prior to riding, you want the coolant temp very warm before riding so you're out of the ECU's "choke" cold-enrichment cycle.

Pintle...

 

Oops lol.

 

It wouldn't be so bad, but I work with fuel injection weekly for the last many many years.

Edited by WALKINGWOUNDED

Hah! I can beat that!

Last time I was at the track I kept turning the fast-idle knob counter-clockwise to lower the idle rpm. Idle got faster so I kept turning it counter-clockwise to try and lower it. I thought I had an air leak because the idle was VERY high. Then I came to my senses and realized I was full "out" rather than full in. Duh. Must have been that nasty finish-line jump flat-land I did earlier in the day messing with my brain cell.

Edited by Eddie8v

Voltage to the injector shouldn't be a problem.  Even though the capacitor may hold voltage after you shut off the engine, once the crankshaft stops moving, there is no rotation signal to the ECU, so it stops sending a on/off ground signal to the injector.  Based on history, it's probably the pinnacle in the injector not sealing off very well after shutdown.  Also all engines have blow by past the rings to some extent, and if it's running rich, it fill the crankcase with excessive hydrocarbons.  And it doesn't have to run so rich that it's blowing black some either.  

 

If it's the injector leaking down after shut off, you should be able to pull the injector and watch for dripping.

 

Assuming that the injector is in fact the problem, is this a design flaw, or can the problem be solved by replacing the injector assembly?

Many have cured the problem by replacing the injector. You could also try and clean yours internally yourself, or send it to a place that will clean and flow test it for you, and verify pintle closure.

Edited by Eddie8v

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