My 105HP(1978) is weak after adding over oil with gas

[liusigou]

my boat engine(1978 105hp) was difficult to start after adding over oil with gas. After burning all the gas with over oil I added the gas with regular oil, but it is weak for the engine. How can I tune my engine up?

I think following

Step 1: changing battery

Step 2:change spark plugs
Step 3:check and cleaning gas filter.

......

Thank you

 

[GA_Boater]

my boat engine(1978 105hp) was difficult to start after adding over oil with gas. After burning all the gas with over oil I added the gas with regular oil, but it is weak for the engine. How can I tune my engine up?

I think following

Step 1: changing battery Why?

Step 2:change spark plugs Yes

Step 3:check and cleaning gas filter. Probably not needed, but it won't hurt.

......

Thank you

How much extra oil did you add?

But check compression and spark. The weakness may be showing a preexisting condition or just coincidence.

 

[liusigou]

Thank ga_boater for your replying. Maybe 20ml oil in 20L gas. It was very difficult to start the engine.when I added over oil. Now it is very weak. So I do not know how to tune it up.

 

[Redbarron%%]

20 Ml to 20 Liter is 1000:1 the way I figure it Milliliter to liter?
50:1 should be the correct number so for 20 liters I would think that ,4 liter would be close.
Maybe 400 ML.?
Instead of too much perhaps not enough and scored cylinders
20 liter / 50 = .4 Am I correct there?

 

[liusigou]

normal 400ML OIL to 20L gas, Maybe I added more. About 420ML oil to 20L. thank you

 

[Redbarron%%]

That should not really be a problem.
The engine should run OK, but smoke a little more than usual with the extra oil.
For break in they suggest perhaps 25:1 anyway.

 

[Tassie 1]

Don't think the amont of oil you are using is causing your problem
that ratio is reasonably close to spec,

do the already suggested compression and spark test,

 

[racerone]

Agreed , do some testing.----20ml of extra oil does no harm and motor will not even know that wee amount.----But it does prove once again that the lubrication in a 2 stroke engine is a mystery to some folks !

 

[jerryjerry05]

Sorry had to ask
You did use 2 cycle oil?
TCW-3 ?

Like the other asked, do a compression test and a spark test.

Does the squeeze ball pump up firm?

 

[liusigou]

The oil 400ml is TCW-3. But extra 20ml oil is not. it is very normal oil for 2 cycle oil. I used it before I started to use TCW-3. I stopped to use after somebody said it is not good enough for the motor.

Also How can I have a compression test? easy or nor? But I can change the spark plugs

 

[liusigou]

I have watched one viedo at Youtube for the compression test? How can I the normal value of compression? What should I do if compression has some issue?

 

[jerryjerry05]

Compression: all cylinders should be within 5# of each other.
If your in the US ?? You should be able to get a loaner tool from any auto parts store.
Every comp gauge will probably read differently.
The actual comp should be 145-150#
But your gauge might read differently.

U-tube video's can help.

A big variance in the readings can mean a rebuild is needed?

 

[liusigou]

After I changed the spark plug and checked the fuel filter, the motor works better. I will continue to check compression. thank you all.