Old Tecumseh engine oil, Synthetic or regular?

copyman

Well-Known Member
#1
I'm sure this had to be discussed on this forum before. What are the opinions for oil in older 4 stroke engines? Specifically TEC H50 from early 70's.

Just use the oil weight in manual specs or synthetic?

Thanks
 

Sooner79

Active Member
#2
I'm sure this had to be discussed on this forum before. What are the opinions for oil in older 4 stroke engines? Specifically TEC H50 from early 70's.

Just use the oil weight in manual specs or synthetic?

Thanks
Use conventional oil (mineral - not synthetic). Older engines weren’t manufactured to as tight of tolerances as newer ones and thus using synthetic oil doesn‘t protect the engine as well and may cause leaks and additional wear on the older engine.
 

copyman

Well-Known Member
#3
Use conventional oil (mineral - not synthetic). Older engines weren’t manufactured to as tight of tolerances as newer ones and thus using synthetic oil doesn‘t protect the engine as well and may cause leaks and additional wear on the older engine.
Thanks. That was what I was thinking.

Something else came to mind, think I read somewhere to use regular gas not super? What about alcohol in the gas, how big of a deal is that? Problem here in NJ is all gas has 10% alcohol added. Does that mean an engine, especially old will never run right with this crap gas?

Take care and thanks again
 

mustangfrank

Well-Known Member
#4
Thanks. That was what I was thinking.

Something else came to mind, think I read somewhere to use regular gas not super? What about alcohol in the gas, how big of a deal is that? Problem here in NJ is all gas has 10% alcohol added. Does that mean an engine, especially old will never run right with this crap gas?

Take care and thanks again
They run better (cooler) with a little alcohol IMO, problem is the alcohol holds water and eats older rubber lines and carb seals especially when stored. Unless you want to pay 5 to 8 bucks a gallon for rec gas just make sure all your lines are newer and drain your bowl for storage longer than a month.
 

copyman

Well-Known Member
#5
They run better (cooler) with a little alcohol IMO, problem is the alcohol holds water and eats older rubber lines and carb seals especially when stored. Unless you want to pay 5 to 8 bucks a gallon for rec gas just make sure all your lines are newer and drain your bowl for storage longer than a month.
As usual great advice. If I just let it run out of gas is that good enough or still need to drain? To drain just remove the adjustment screw on bottom?
Like I mentioned in another post the original carb had a drain on bottom. I think it was a drain you pushed on it and gas came out.

Thx again
 

mustangfrank

Well-Known Member
#6
As usual great advice. If I just let it run out of gas is that good enough or still need to drain? To drain just remove the adjustment screw on bottom?
Like I mentioned in another post the original carb had a drain on bottom. I think it was a drain you pushed on it and gas came out.

Thx again
Yeah, the bowls with the little plunger drain are handy...if I remember to actually drain it!
 
#11
I run a fleet department for a small town. We were having constant and ongoing issues with small engine equipment, a mix of brand new to very old stuff. About 5 years ago as a test I switched from buying regular gas with 10% alcohol to clear gas (no alcohol). I was not sure if it would help or not. Within a year more than half of the run ability issues stopped. I used to be constantly rebuilding carbs and other fuel related parts. Now I seldom do, and the equipment seems to start/run better too. I was not sold when I first did the test (I am very frugal and hate to waste money) but after dealing with it I am totally sold on no alcohol in small engines, especially older ones. If you can't but clear gas locally, go to an airport and buy airplane gas. The only issue with it is that it is highly leaded, don't put it it in a car with an cat converter.
 
#13
There is rec fuel in the Detroit area...I think by any lake. I run it in the dirt bikes quads and mini bikes..in Houghton lake its 3.60 ish a gallon.....the dirt bikes love it...so does my chain saws.
 

copyman

Well-Known Member
#16
I run a fleet department for a small town. We were having constant and ongoing issues with small engine equipment, a mix of brand new to very old stuff. About 5 years ago as a test I switched from buying regular gas with 10% alcohol to clear gas (no alcohol). I was not sure if it would help or not. Within a year more than half of the run ability issues stopped. I used to be constantly rebuilding carbs and other fuel related parts. Now I seldom do, and the equipment seems to start/run better too. I was not sold when I first did the test (I am very frugal and hate to waste money) but after dealing with it I am totally sold on no alcohol in small engines, especially older ones. If you can't but clear gas locally, go to an airport and buy airplane gas. The only issue with it is that it is highly leaded, don't put it it in a car with an cat converter.
Speaking of lead in gas a friend had 62 corvette think it was the 70's or 80's we took it for a ride and he had to stop at auto parts store before getting on highway, think he said it was a lead additive? Maybe octane? He said it ran like crap without it.
 

copyman

Well-Known Member
#17
There is rec fuel in the Detroit area...I think by any lake. I run it in the dirt bikes quads and mini bikes..in Houghton lake its 3.60 ish a gallon.....the dirt bikes love it...so does my chain saws.
I've only saw "off road" diesel advertised here in NJ. But I really haven't looked hard for "off road" alcohol free gas.

If you setup the carb with NO alcohol gas then put gas with alcohol back in won't the carb have to be adjusted again?

There is a small airport close to me and they sell regular aviation fuel & jet fuel. Here is their website with current pricing

FBO & Flight Services info for K17N
Providing high quality fuel and services to you and your customers, from Phillips 66 Aviation.

Ph: 856-629-3033-Freq: 122.8WebsiteE-Mail

ServiceJet100LL80/87MoGas
Full4.254.95
Last Update: 10/03/2020 11:39
PRICES GUARANTEED by FBO.
Self
4.95​
Misc. Info:Address: 1531 NORTH TUCKAHOE RD WILLIAMSTOWN, NJ 08094
 

desert rat

Well-Known Member
#18
Speaking of lead in gas a friend had 62 corvette think it was the 70's or 80's we took it for a ride and he had to stop at auto parts store before getting on highway, think he said it was a lead additive? Maybe octane? He said it ran like crap without it.
Oh those were the days. High compression motors factory built to run ethyl(yellow) gas. Then unleaded cam along and jacked us up. You needed lead for the valves and octane boost to stop the pinging. I had a '69 402 rat big block running 13/1 compression from the factory, still have it but I'm down to 10/1 just to get by on this new crap fuel.
 

mustangfrank

Well-Known Member
#19
I've only saw "off road" diesel advertised here in NJ. But I really haven't looked hard for "off road" alcohol free gas.

If you setup the carb with NO alcohol gas then put gas with alcohol back in won't the carb have to be adjusted again?

There is a small airport close to me. Next time heading out that way will bring 5 gal can and see if they will sell it to me.
Shouldn't have to adjust if the octane is the same, it's only 10% alcohol in most states and Northern states are sometimes seasonal. Do some research before messing with AV gas, octane ratings can be high and you'll actually lose performance if your engine isn't built for it.
 

copyman

Well-Known Member
#20
Shouldn't have to adjust if the octane is the same, it's only 10% alcohol in most states and Northern states are sometimes seasonal. Do some research before messing with AV gas, octane ratings can be high and you'll actually lose performance if your engine isn't built for it.
I forget what year unleaded gas came out? This TEC engine was from 1972. So if it was before unleaded then it should run better with the AV gas?
 
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