Topic: Left my petcock on all winter

[vincentvega]

So as the title implies, I left the petcock open on my '72 CB500, it was in reserve instead of the off position. I tore the bike apart to change the needles in my carbs to fix a run rich issue and the airbox was soaked. After I cleaned everything back up I changed the oil (the filter was newer so I didn't change it) and changed the plugs because of a run rich issue from last year.

The bike seems to run pretty well aside from white smoke from 1 and 2 which I hope will clear out as I run the bike more. Before I run the bike too much though is there anything else I need to be worried about from having left the gas on all winter?

[Whaleman]

The new gas is bad compared to 30 years ago. I have given my opinion many times. It is not worth trying to save old gas over the winter. Dump out the old gas into a funnel and can and put it in the car. Drain the float bowls. Leave the gas cap open and dry out the inside. Spray fogging oil into the tank. One can will last a decade. Put the tank inside for the winter if possible. In the spring put in fresh gas with Lucas Ethonal Fuel Treatment. Use every tank unless burning full tanks. No problems. Dan

[vincentvega]

Oh yes I forgot to mention I drained everything and I also use non-ethanol fuel; the petcock was leaking past the screws so I drained the tank and fixed that as well. The tank itself looks like it was treated by the PO, it has a cream colour coating on the inside, no rust.

[bjbuchanan]

Change the oil, probably gas contaminated

[Deltarider]

Having experimented with both, I prefer to have gas in the carbs so the rubbers don't shrink or become britle. Just drain say every two months, pour what you've drained in the tank and open the petcock for a few seconds to refill the floatchambers. Worked for me and no nasty surprises like leaking seals.

[PeWe]

What about start the engine running warm once a month and consume gas in the carbs, let new in from tank?

[vincentvega]

Well the problem was more to do with evaporation into the crank case, this was not done on purpose, my shed became inaccessible before I winterized the bike due to heavy snow. Here is what I did in the summer upon discovering my error:

1) Drained the fuel from the carbs
2) Drained what was left from the gas tank
3) Removed the carbs to replace needles and emulsion tubes to fix a previous run rich issue
4) Fixed my petcock so it wouldn't leak past the screws anymore
5) Changed the oil (there was gas in it from all the evaporation)
6) Cleaned out the fuel from the airbox that had evaporated

The bike started fine but was smoking on 1 and 2, plugs fouled it wouldn't start again yesterday. I discovered additional fuel/oil in the crankcase vent tube that was flooding the airbox with gas, the inlet is right in front of cyl 1-2 so I think that was the cause of my smoke.

Anyway that's my story for today, just looking to see if I'd covered all my bases so I don't blow myself up or wreak the bike, but it looks like the crankcase vent tube was a piece I had missed. If anyone has anything else I may have missed please let me know.

[Deltarider]

What about start the engine running warm once a month and consume gas in the carbs, let new in from tank?

I don't like it, it will make your exhaust rot. I've always used my motor for at least 25 minutes so it is truely warm. My original 4 in 4 exhausts served over 75.000 kms. My second set has done around 60.000 kms and still look good on the outside.

[Clasico]

I'd never thought that leaving your petcock open for just a winter, let alone gas on the tank, could be a real problem.

[Deltarider]

I'd never thought that leaving your petcock open for just a winter, let alone gas on the tank, could be a real problem

Well, you're right, it isn't. It's one of these things that is echoed over and over. Four to five months shouldn't be a problem.

[mrrch]

One other thing you might check as well is the airfilter. I don't know if it is possible but if enough fuel was in the airbox it could possibly contaminate a paper airfilter by wicking up the fuel and swelling and clogging.