How do I determine the cc's of my '97 T90TSLEU engine?

[JW Camp]

My "Seloc" manual doesn't give me a clue as to differentiate such. The manual just covers both. The manual also doesn't give me a clue whether my motor is a 90? or 60? looper. Had to call a boat repairman at a dealership and they frown on such doings. It is a SPL engine if that means anything.

 

[racerone]

It will be a 90 degree crossflow.---About 1600 CC displacement.

 

[JW Camp]

Is there a difference between a "crossflo" or a "looper" engine? The Johnson mechanic told me I have a 90? looper.

 

[racerone]

Your mekanik may be mistaken about a "90 HP 90 degree looper " ----Post a picture of engine with cowing off to settle this in an instanty.------Or are there 2 carburetors with 2 barrels each or 4 seperate carburetors??

 

[JW Camp]

I will check tomorrow. Never paid any attention. The mechanic said a "looper" is the type of piston used. It is designed to give more hp.

 

[ondarvr]

If you have SPL its not a looper.

 

[Chris1956]

Actually, "looper" is an abbreviation for Loop Charged. Loop Charged refers to the type of exhaust scavenging the motor has.

A cross flow motor will have a single transfer port and a single exhaust port. The piston will usually have a raised portion on it top to help sweep the exhaust out the port.

​A loop charged motor will usually have several transfer ports and a single exhaust port. These multiple transfer ports push the exhaust out more efficiently increasing power and decreasing the waste of raw fuel. These motors usually have a flat top piston.

​Loop charged motors are a lot more difficult to manufacture, due to the multiple transfer ports that need to be cast into the block, along with water passages.

​The most advanced loop charged two cycle motors I have seen had 4 transfer ports, 1 exhaust port, and an elongated intake port to allow a direct charge into the combustion chamber. They were known as seven port, loop charged motors and were used on motor cycles.

 

[JW Camp]

Checked this morn and it has 2 carbs W/2 intakes each.

I want 2 thank all who have helped me identify my motor alittle better than the Seloc manual gives me!

 

[interalian]

A word of advice: ditch the Seloc manual and get a factory service manual for your year motor. It will pay for itself many times over if you plan on doing anything beyond minor maintenance. Seloc manuals are good bathroom reading, and include an emergency supply of paper...

 

[racerone]

Loop charging was used on the old LAWNBOY power mowers way back in the 1950's--------Rebuilding a 1958 vintage one over the winter , just because I want to and it can be done.