My words of Husqvarna Wisdom

Here's what I have learned through my decades of experience with the awesome husqvarna motorcycles. Let's say with two stroke bikes in general.

1. When purchasing a used bike that hasn't been running for years and was sitting flooded to the point you take the spark plug out and turn the bike upside down to remove what looks like or appears to be gallons of gas your need to change the base gasket and crank seals. The base gasket has softened due to being wet with gas. You will see so much gas come out of the spark plug hole don't get execieted you didn't strike oil like opec. Make sure you have a bucket handy. My point is someone couldn't kick start it and flooded it. At this point the base gasket is soaked and soft. You probably have a good running engine. Why push it with an air leak till it seezes. Why buy a new piston and bore it when you can tear it down and change the crank bearings, crank seals, measure the bore and piston and get a gasket set. You could save some $$ if the piston is still good. Check the piston ring end gap too. You made need a new ring. Remember to relap the head to the cylinder to renew the seal.

Trust me a gas soaked air leaking base gasket will get us every time. Just because she runs at first after unflooding it doesn't mean it's going to last. Also with today's New blend of gasohol(corn alcohol) the old seals won't last anyway.

Even if your older husqvarna bike is running great now, but it's never been refreshed, do you feel lucky? We either pay less up front to know for certain it's good or pay more later after it seezes. Then it's the long push if your out in no man's land riding when it seezes. I hate it when the trail has mile markers pushing gets old quickly, it's like a walk of shame.

Just some of my old dirtbiker wisdom for you to think about. I learned the hard way. I'd rather ride then push. Bigbill

Well spoken Bigbill,
Below are some photos I took of my 1970 400 Cross cylinder after a race. The bike just kept losing power, I failed to realize what was happening until it tried to seize. Upon tear down, I found the base gasket was deteriorating allowing it to suck air into the transfer ports. I had done a complete tear down/ rebuild about five years earlier, but then the bike sat unused until I began vintage racing, so I could say it was a "new" gasket, but in reality it was about five years old. Lesson learned.
Steve

Unfortunately I had to check all my cranks now on these purchased engines before running - after finding more that 50% of teardowns with some sort of galvanic action or moisture pitting on the crank pin. These are engines from bikes I am buying for rebuild or parts, that have sitting for a while. These have not been run. Just something I plan on doing when I pick up a bike and do a tear down.

Of course all don't have to be done, but after seeing it I am cautious now.

Oh, I know and a lot look good up top after cylinder removed. Then down inside, the cases are rotted bad or all the way through!

I think Gary is more on the right path. If the engine has been full of gas/whatever the crankshaft itself might have corrosion. Only time I had an issue with the base gasket was when I re used one.

But now not knowing the history of the bike with it being so old and it's still running great it maybe time to refresh it before any problems start. That's my plan. Time takes its toll on seals and moving parts. Most of my used purchased huskys were complete but non runners. The few that did run needed crank seals and bearings sooner or later. Once it's apart we might as well address the piston and cylinder. If we restore it correctly it should last another 35++ years with the proper care. There are no short cuts on restoring these awesome pieces of quality Swedish steels.

I learned the hard way restoring gravely tractors. I now tear them down to the last bolt then inspect every part and replace if needed. I sold a near new tractor. These are 700lb walk behind tractors.

I never replace original Husky bearings unless they NEED it, you can not find bearings today of the quality that came in these bikes, same with Maico, KTM/Penton, Sachs or any other European bike of that era. I'm a bit skeptical of the soaked base gasket theory. I also think its a lot more likely for corrosion to happen in a dry case where the crank is exposed to air than one where the crank is submerged in fuel/oil.

My first 390 was the worst flooded engine I ever seen. The problem starts when it sits being flooded. The case was filled up with gas completely. When I tipped the bike upside I swear a gallon of gas came out of the spark plug hole. Now how long did it sit like this? The base gasket was soft like a sponge.

Could be, I have had bikes with the cases full of fuel, but none ever sat like that more than a few days. I guess if they sat like that for years it could soak the base gasket.

I purchased my first 390 from a bike junk yard. Who knows how long it sat flooded from the previous owner.
The sad part is after clearing the flooded condition she ran till the base gasket went. The bike was perfect before they flooded it.

Now I worry about this new blend of gas being it's effect on the new seals that are made with the older material. My older husqvarna chainsaws had fuel line problems the line just melted because of the new gas. That was a few years back the blend of gas has changed many times since them. Keep in mind this new gas can have an affect on seals, gas hose and gaskets. The carb bowl gaskets could melt too(older). Where going to have to keep an eye and ear on it all if it sounds funny or leaks.

Bigbill's base gasket theory seemed baseless, so I tested it. I've been soaking 3 different NOS Husky base gaskets in regular gas for the past week. I have been checking them daily and they are perfect. Perhaps if you make your base gaskets out of Fruitloops boxes, then they fail.

Just go on fuel locater and find stations that use no ethanol fuel.
I use it in bikes, saws,tractors, etc..... And doesn't go bad.
If I put ethanol fuel in my old John Deere 4020, the carb leaks from the needle rubber.
If I use non ethanol fuel it stops leaking.
Most of newer seals are engineered to combat the ethanol issues.
That's why you want to spend good money on good seals.

But aren't we buying new seals that aren't new enough to be ok for ethanol?

No, the seals are new unless you intentionally buy NOS Husky seals. The solution is dont use ethanol fuel.

I maybe worry too much but this new blend of gas scares me. I don't like repairing things twice. I'll look for standard blend gas.

Well methanol or ethanol does not mix with oil, so why would you use it.

I didn't know it doesn't mix with oil. Maybe instead of running castor oil I should be running a synthetic like maxims 927?

I'm to the point now even if it runs how old is the motor? It's not worth taking a chance in running it because it could be a matter of time before she goes south. All my engines will be refreshed over this winter. It's pay for gaskets, seals, crank bearings now and maybe a piston and rings or wait till she lunches and replace the cylinder and or crank too? Pay less now or pay more later.


Fact everyone thinks a car that's been sitting in a garage for fifty years with low mileage is like new? My point is wether it runs and was driven or not time takes its toll on gaskets, seals, rubber parts etc. Bikes are no different. Just touch the old tires and see how hard the tires have become. They lost there flexibility.

Maxima 927 is a synthetic base with about 30-40% castor. Castor oil is the only oil that WILL mix with alcohol.

On the base gasket issue, you have to add the fact that the gasket is compressed by the torque of the cylinder so its even less likely that it will absorb fuel than just soaking one on the bench.

yup klotz benol is one of the top mixes for alcohol burning 2 strokes. its straight castor. i run the super techniplate, which is 80% synthetic, 20% castor. the benol is a little dirty and is a race only oil.
i know its not good but my 88 250 has all stock gaskets except for the side cover. and yes i run ethanol in it. the only place around here that has ethanol free is 87. im thinking of buying some mild octane race gas and cutting it with the 87 to avoid ethanol. in the meantime, i have been running startron and drain my fuel during the winter. no carb problems