[Grizzlefoshizzle]

Hi All,

I only run my 450 for very short intervals every couple of weeks. A few months ago I notices it started to sometimes pour blue smoke for 5 minutes after starting and then runs fine, other times it's fine from the start. The old battery was dead so it wasnt getting much riding recently but today I put a new battery in it and took it for a spin. Half way through the spin I noticed it started to pour blue smoke on idle. This cleared with giving throttle but returned when stopped and idling again. I pulled the dipstick then and found the level to be at least twice the height of the max mark. The oil itself looks fine. No milky appearance that you'd expect with coolant/water but it does appear to have a gas smell to it.

Am I leaking Gas into the combustion chamber and is the high level in the crank case then causing it to burn oil? Or is there another cause? The air box is dry. No sign of gas or oil.

TIA

 

[Rinspeed]

I would probably change the oil and send out a sample to Blackstone for analysis.

 

[Vincent]

Don't run it until you change the oil and filter

 

[reogem]

Float is sticking flooding the crankcase with fuel. Don't run it until you get the float fixed and do an oil change as @Vincent has recommended.

 

[STEEVO]

@reogem and @Vincent spot on 💯💯
Definitely no need to send the oil off for analysis 🙄 (surprised this is even a thing) sounds like you have it figured out already.

High oil levels (and should also notice lowered fuel levels) and smell of gas are signs of that carb pouring gas when it’s not running. It’s then filling the crankcase with fuel because float isn’t floating or needle isn’t sealing properly.

Personally I would do a carb cleaning rebuild the same time as the oil change and then monitor close after. Do not run the bike with this gas enriched oil as it doesn’t lube very well. I would do these steps asap before running the bike much more. Your asking for piston rings or bearings to fail.

Good luck and let us know what’s up once you pin it down.

 

[Grizzlefoshizzle]

Took float sump off and inspected the needle valve, float etc. O-ring on the outside of needle valve seat looked a little damaged so replaced it. Float and needle valve all look to be operating ok. Oil and filter changed today. Restarted the bike 2 or three times and no sign of the blue smoke so far. Will take it for a spin next weekend to see of it appears and keep an eye on the oil level to see does it start to rise again.

Thanks for the help. As always, it's much appreciated. I'll keep you posted with how it goes.

 

[reogem]

A bad float will flood the crankcase with the machine just sitting.
FYI: it always a good idea to shut off the petcock when storing the rig.

 

[Rinspeed]

A bad float will flood the crankcase with the machine just sitting.
FYI: it always a good idea to shut off the petcock when storing the rig.

Wouldn't you have a large puddle of gas on the floor from the overflow before any made it's way into the crankcase.

 

[reogem]

The float chamber vent is located higher above the needle and seat plus the carb is tilted toward the intake.

 

[Grizzlefoshizzle]

Bad news.

Started the bike today and it was smokey from the start and didn't improve with a 5 minute spin around the yard. Pulled it back in to check the oil level and it was 2 or 3mm higher on the dipstick and more alarmingly, there's was a milky streak on the dipstick. I then noticed a drop on the ground underneath which turned out to be coolant from the reservoir breather hose. I opened the radiator cap then to find the level has dropped almost to the bottom which is leading me to believe my head gasket is gone again only 20hrs after replacing it the last time. Not sure how this has happened as Its never brought on the temp light and both the fan switch and the temp switch are brand new. I also checked the head the for warping to the specs in the manual when replacing the gasket the last time.

So, looks like the cause of my smoking is coolant leaking into the chamber and crank case. Not looking forward to pulling it apart again and not sure how I'm going to stop this from reoccurring?

 

[STEEVO]

Bummer man!! Personally I would get a new quality jug, new quality piston/rings and use OEM head gaskets.