Export thread

My mower cub cadet XT1 LT46 will exhaust some blue smoke and then stop. It happens when first started? Told that was normal? Told to use synthetic oil 20w50 outdoor power equipment ? Any commets. Thanks, Kim

Roadcadet said:

Told that was normal?

Click to expand...

Don't think new mowers do that. So normal, would say no.

Roadcadet said:

Told to use synthetic oil 20w50 outdoor power equipment ?

Click to expand...

Sounds awful thick. Probably be fine in 100+ F temps. It's only a 20 grade thin oil. Follow what your engine manual states for oil.

Most likely it is oil seeping past the rings while setting overnight or longer. And then burns off on first startup. Shouldn't happen but is quite normal for a lot of engines.

My first question would be is the oil level hi? If so, does it smell like it has gas in the oil? Fuel will overthin the oil, raise the level and cause smoking.

I use Pennzoil 10W 30 year-round. Synthetic is a waste of money and not recommended on a new small engine. Synthetic can actually delay piston ring break-in.

A puff of smoke on a new engine at startup is not uncommon but should go away after the first 25 hours of break-in run time.

If it continues, there is a problem with the valve guides or the piston rings.

20W 50 is used in larger automotive engines and too thick for small engine.

My first question would be is the oil level hi? If so, does it smell like it has gas in the oil? Fuel will overthin the oil, raise the level and cause smoking.

I use Pennzoil 10W 30 year-round. Synthetic is a waste of money and not recommended on a new small engine. Synthetic can actually delay piston ring break-in.

A puff of smoke on a new engine at startup is not uncommon but should go away after the first 25 hours of break-in run time.

If it continues, there is a problem with the valve guides or the piston rings.

20W 50 is used in larger automotive engines and too thick for small engine.

Auto Doc's said:

I use Pennzoil 10W 30 year-round. Synthetic is a waste of money and not recommended on a new small engine. Synthetic can actually delay piston ring break-in.

Click to expand...

Old outdated information. This saying is not true and may of never been true. Most of the small engine manufacturers are not even offering dino oil as an option in their own branded oil. So synthetic oil in a new engine is fine.

Agree. The ol' don't use synthetic oil in a new engine is garbage. All oils are formulated to be "roughly" the same for specific vehicles. Also in the USA, printing synthetic on the bottle doesn't mean it's 100% synthetic. Might be ONE item in the add pack that is synthetic and they call the entire brew synthetic. Not true in Europe. Over there if the bottle says synthetic, it is true. Redline and Motul are synthetics. Anything that is not a group 4 or 5 is dino juice.

slomo said:

Agree. The ol' don't use synthetic oil in a new engine is garbage. All oils are formulated to be "roughly" the same for specific vehicles. Also in the USA, printing synthetic on the bottle doesn't mean it's 100% synthetic. Might be ONE item in the add pack that is synthetic and they call the entire brew synthetic. Not true in Europe. Over there if the bottle says synthetic, it is true. Redline and Motul are synthetics. Anything that is not a group 4 or 5 is dino juice.

Click to expand...

True. Dino oil with synthetic additives can be called synthetic oil.

Vette's and Porche's just to name 2 are factory filled with group 3 Mobile 1. They are "synthetic".

Ever notice how cheap Mobile 1 is at wallymart? Now price Redline or any real synthetic.

slomo said:

Agree. The ol' don't use synthetic oil in a new engine is garbage. All oils are formulated to be "roughly" the same for specific vehicles. Also in the USA, printing synthetic on the bottle doesn't mean it's 100% synthetic. Might be ONE item in the add pack that is synthetic and they call the entire brew synthetic. Not true in Europe. Over there if the bottle says synthetic, it is true. Redline and Motul are synthetics. Anything that is not a group 4 or 5 is dino juice.

Click to expand...

Conventional and Synthetic oil are both based on oil stock. Conventional oil is refined and the refinement process (cracking) produces different products at each stage (diesel fuel,gasoline,kerosene, oil stock for motor oils). The resulting lubricant molecules are not of consistent size.

Synthetic oil is created in the laboratory to create a more consistent molecule sized of lubricant to the desired specification.

Both have additives be it zinc or other additives.

You did not say what engine is on the mower. Kohler had that issue but it has been to long I don't remeber the fix.
Consider the cylinder lays flat, oil drains off the piston and cylinder and will seep past the piston rings especially if the ring gaps especially if the are on the bottom of the piston and especially if the are lined up.
It can also be caused by storing the mower with the engine leaning back which will cause oil to bypass the piston as oil will flow into the cylinder.
Unless it is excessive there is nothing to be concerned about, many new engines have that "problem".

Roadcadet said:

My mower cub cadet XT1 LT46 will exhaust some blue smoke and then stop. It happens when first started? Told that was normal? Told to use synthetic oil 20w50 outdoor power equipment ? Any commets. Thanks, Kim

Click to expand...

I just bought a new XT1-LT46 myself and haven't yet reached the 5 hour mark for oil and filter change. I didn't notice the Kawasaki engine mentioned in this discussion but the engine manual that came with my mower recommends 10W-40 for most temperature ranges. It made no distinction between synthetic and conventional oil. I suspect it will be happy as long it's the proper grade of oil and sufficient quantity.

Hi Chilidawg,

There is no magic life extension to using synthetic in an air-cooled engine, but it will not hurt it.

I use Royal Purple (RP) 20W 50 in my '95 Harley and I can tell a performance difference with that oil. In a mower it would probably be "over kill". RP does make 10W 40 also.

I only mention RP because it has a stellar reputation in the Harley community.

Thank you for the feedback. I'll probably just use a good grade conventional 10W-40 and change the filter each time. I actually considered running Delvac 15W-40, but perhaps overkill?

Chilidawg said:

Thank you for the feedback. I'll probably just use a good grade conventional 10W-40 and change the filter each time. I actually considered running Delvac 15W-40, but perhaps overkill?

Click to expand...

Just don't use any generic brand is my opinion. All name brand oil is developed with certain additive packages. The generic brands are what I would call unregulated "vat wash" of the process and much of that is blended with so called "recycled" oil products to keep the cost down.

The base oil "cracking" process is pretty straight forward; it is the oil distributors who put the additive packages in the oil to customized it.

Check online for guys by the name of Lake Speed Jr. or Bob the oil guy. They go into detail about the process. It is lengthy but interesting reading.

I would just use the oil from the engine manufacturer. Yes, it's way more expensive than what you can get at Wallyworld, but...
- How much do you really use? I do one change per year. 2 qts. That's not going to break the bank.
- You know that the oil from the mfr will absolutely have the right additive package for your engine.
- No in-depth analysis needed. No need to figure out if synthetic is needed. Or zinc. Or any other additive.

Just buy a 12-pack from Kohler, Briggs, or Kawasaki and be done with it. I have two riders, both with Kohlers. I bought a 12-pack of oil, which will last me 3 yrs.