97 120 force (smokes 5 packs a tank)

sightsrv

Petty Officer 3rd Class
Joined
Nov 9, 2012
Messages
82
Hey..Bought a 97 nitro 700lx with a 120 force. Boat and motor are brand new might as well say.
Found a add for sale said "never used" "garage kept" yeh right. 1st one ever seen was true!!!!!!!!
Anyway the 120 just hit the key for 2 seconds it starts everytime and runs just like new. Gets the
boat up with 2 people to 52mph with no problem. Two things. 1st is not sure but do belive thats
not all it will do. Give it all the gas and just feels like its governed or something, make sense?
2nd is 5 packs might be off base its realy not that much. At idle its enough to notice the smoke.
I know its normal but I guess theres no way to stop it right? Another is is there a way to add
some oil injection thingy so ya dont have to guess how much oil to mix or is it even worth the
cost? Was thinking about a newer I guess 115 since dont look like can buy a 120-125 anymore.
Looks like a dumb idea so far would cost more than a 97 is worth. Need advice much!!!!!!
Theres a lot I do not know. Thanks!!!!!!!!!!!!!!!!
 

ajgraz

Lieutenant Commander
Joined
Mar 1, 2010
Messages
1,858
Re: 97 120 force (smokes 5 packs a tank)

Is this your first outboard? 2-cycles do smoke, especially cold / first start up and at idle. Synthetic 2-cycle oil can reduce that, though it does cost more. What gas-oil ratio are you running? (Should be 50-1; if you're using a mix like maybe 25-1, that would make more smoke and possibly cause some power loss)

As for oil injection...as far as I can tell, most people who have it look to get rid of it and go back to old-fashioned pre-mixing. And I agree with them, one less thing to go wrong and destroy the powerhead.
 

batman99

Petty Officer 1st Class
Joined
Sep 13, 2012
Messages
393
Re: 97 120 force (smokes 5 packs a tank)

At base of your motor (transom / Starboard side area), look for the serial number plate. Your Force 120 HP engine probably has a max RPM speed of 5250. Faster than 5250, its speed restrictor will kick in (and bog its enging back down). Thus, stopping RPM from going faster. For boat engines, don't focus only on MAX "ground speed" (like MPHs). Always focus on engine RPM 1st. Then, ground speed 2nd. Just like vehicle engines, many boat engines run best at 80-85% of its engine's max RPM. Especially in the long run...

If your current 2-stroke oil smokes, use a different brand of oil. For example: HP Marine Synthetic 2-Stroke Oil (HPM) And yes, 50:1 is recommended mix for Force 120. Some oil brands smoke bad and others not as bad. For proper mixing, simply fill 5 gallon can with gas, add 50:1 ratio of oil, shake 5 G container, then pour that container contents into your boat's tank. Thus, ensuring 50:1 ratio mix every time. Was told to use high octane / Premiem gas (that has no ethonol dilution) for best results. And, also install a Fuel / Water Seperator filter as well. Thus, trapping natural water condensation from boat's onboard gas tank as well. 2-stroke engines don't like water in the gas. iboat's Water / Fuel Seperators are very good pricing as well.

Also... What size (pitch) of prop is on your boat now? If you have too low of pitch prop (like 17"), your boat will have lots of bottom end take-off but at faster MPH speeds, its engine will over rev (try to go above 5250 RPMs). If too much bottom end power, one might want to install a 19" Prop. Thus, allowing more ground speed without hitting engine's MAX RPMs. What are the last few numbers stamped on your boat's prop? Is the prop a SS (steel) or aluminum material?

Hope these ideas help...
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: 97 120 force (smokes 5 packs a tank)

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You are expecting too much! 52 MPH is an excellent speed--even for other brand engines of the same horsepower. As for feeling like it is "governed" The last 1/4 travel of the control handle opens the carb butterflies wide. The engine makes a lot more noise, uses a lot more fuel, and only goes maybe 2 MPH faster.

As an example, Here is a 125 on a small 14 foot boat and it only tops out at 60 with me alone in it. ( the 125 is badged as an 85)
 

sightsrv

Petty Officer 3rd Class
Joined
Nov 9, 2012
Messages
82
Re: 97 120 force (smokes 5 packs a tank)

Is this your first outboard? 2-cycles do smoke, especially cold / first start up and at idle. Synthetic 2-cycle oil can reduce that, though it does cost more. What gas-oil ratio are you running? (Should be 50-1; if you're using a mix like maybe 25-1, that would make more smoke and possibly cause some power loss)

As for oil injection...as far as I can tell, most people who have it look to get rid of it and go back to old-fashioned pre-mixing. And I agree with them, one less thing to go wrong and destroy the powerhead.

Yeh its my 1st one. I say that syn oil will try that. Its running 50-1. Understand talked with a guy today tried the injection route, said he almost killed his motor...
Thanks Much!!!!!!!!!!!!!!!!!
 

sightsrv

Petty Officer 3rd Class
Joined
Nov 9, 2012
Messages
82
Re: 97 120 force (smokes 5 packs a tank)

At base of your motor (transom / Starboard side area), look for the serial number plate. Your Force 120 HP engine probably has a max RPM speed of 5250. Faster than 5250, its speed restrictor will kick in (and bog its enging back down). Thus, stopping RPM from going faster. For boat engines, don't focus only on MAX "ground speed" (like MPHs). Always focus on engine RPM 1st. Then, ground speed 2nd. Just like vehicle engines, many boat engines run best at 80-85% of its engine's max RPM. Especially in the long run...

If your current 2-stroke oil smokes, use a different brand of oil. For example: HP Marine Synthetic 2-Stroke Oil (HPM) And yes, 50:1 is recommended mix for Force 120. Some oil brands smoke bad and others not as bad. For proper mixing, simply fill 5 gallon can with gas, add 50:1 ratio of oil, shake 5 G container, then pour that container contents into your boat's tank. Thus, ensuring 50:1 ratio mix every time. Was told to use high octane / Premiem gas (that has no ethonol dilution) for best results. And, also install a Fuel / Water Seperator filter as well. Thus, trapping natural water condensation from boat's onboard gas tank as well. 2-stroke engines don't like water in the gas. iboat's Water / Fuel Seperators are very good pricing as well.

Also... What size (pitch) of prop is on your boat now? If you have too low of pitch prop (like 17"), your boat will have lots of bottom end take-off but at faster MPH speeds, its engine will over rev (try to go above 5250 RPMs). If too much bottom end power, one might want to install a 19" Prop. Thus, allowing more ground speed without hitting engine's MAX RPMs. What are the last few numbers stamped on your boat's prop? Is the prop a SS (steel) or aluminum material?

Hope these ideas help...

Yes helps very much..All you guys are great!!!!!!!!!!!!!!!!!
Bat to be honest I dont know what size the prop is. Or what type would be best. Its a 3 banger, fins if helps. Take a closer look 2morrow. Glad ya mentioned the gas thing. Have all the books came with the 97 including his invoice!! The book with the motor says only use no more than 10% ethonol and what ya said about a filter. Book says quicksilver brand, sound right? Have to figure out where can get that. No chance around here finding gas without that mess. Got ya about rpm thingy, ya know fast is fine but hardly ever give it all. Just noticed the stick ran out and knew it wont getting all. Oh iboats has that filter? Thanks will look it up and order one. Will check the prop am and get back with ya.
Thanks!!!!!!!!!!!!!
 

sightsrv

Petty Officer 3rd Class
Joined
Nov 9, 2012
Messages
82
Re: 97 120 force (smokes 5 packs a tank)

View attachment 174468View attachment 174469View attachment 174470

You are expecting too much! 52 MPH is an excellent speed--even for other brand engines of the same horsepower. As for feeling like it is "governed" The last 1/4 travel of the control handle opens the carb butterflies wide. The engine makes a lot more noise, uses a lot more fuel, and only goes maybe 2 MPH faster.

As an example, Here is a 125 on a small 14 foot boat and it only tops out at 60 with me alone in it. ( the 125 is badged as an 85)

Your right I know. Thats more than fast enough. Its a 97 but its new to me. I guess same as back when we were teenagers ya know? Got a new toy have to see how fast will go.;)
Thanks Much!!!!!!!!!!!!!!!!!
 

batman99

Petty Officer 1st Class
Joined
Sep 13, 2012
Messages
393
Re: 97 120 force (smokes 5 packs a tank)

.

Yes. iboats sell Fuel / water seperator kits. If wondering, I bought the "Sierra Gasoline Fuel Water Separator Kit - 21 micron" unit and it works great. If wondering, I installed between onboard gas tank and its factory gas filter. Thus, allowing the mercury gas filter (rated for the Force 120 engine) to do its thing. If one gets the 10 micron water / fuel seperator, there might be "too much" filtering. Thus, 21 micron + factory mercury inline gas filter works for me.

For your boat's prop, focus on its long number - stamped on its outside shaft. The last few digits of its long number is the Pitch size. For example, 17P, 19P, 21P. As a general statement, 17P create more bottom end hole-shot (but hits rev limitor at Wide Open). The 21P creates faster MPH (but makes hole-shot sluggish). Always best to confirm your boat's factory PROP size and go -2 or +2 sizes from it (depending on your boat's uniqueness). Some like 3 blade props and others like 4 blade props. Each has their pros and cons. My one boating buddy uses his 3-blade 19P aluminum for general touring and 4-blade 17P aluminum when his boat is loaded down and doing tubing. It's always best to have 2 props. One as your main prop and the other as a sudden backup. If your main prop dings and chips, you can immediately replace with your backup prop - instead of waiting weeks for a replacement. If wondering, I recently bought an 3-blade 19P alumimum prop off iboats as well. Easy sizing, great prices and shipping time was amazing as well. Once you get more comfortable with your boat, do obtain a 2nd prop - same size or perhaps slightly different size (if needed). Or, go with 3 blade for distance touring and 4 blade to tubing / sking. Which ever works best for you.

On your '97, do detailed inspection its many gasline hoses as well. re: Inside the hood, inside your boat and if needed, do replace the older age hoses. Hoses go hard over time and if gone hard, they crack and leak air as well. Best to install new gasline hose rubber (simply take hoses to your local auto parts store and they do sell "cut to lenght" replacements) before an air leak is discovered. 2-stroke engines don't like air leaks either. Most boat parts stores charge way too much for gasoline rubber hoses.

The Force 120 is a very heavy weight engine. When transporting on a trailer, the heavy weight motor can create cracks within its transom. To eliminate pressure cracks, do install a transom saver bar as well. re: http://t3.gstatic.com/images?q=tbn:ANd9GcTYSCqRLEur3Au6_5gOtDB3HifkoZckvefVgKwXTUIS81PQ2p7TWA For transom saver bar, do visit your local boating parts store. Some are better design than others. Once you get a good design, do shop around. Prices dramatically vary for the same item.

If forced to use ethonol gas (due to your unique region), do add stablizer additive to each tank. Especially if your boat may sit for 4+ weeks. Uknown to some, ethonal gas can seperate into its 3 major components. This is called "phase seperation". For more details, surf: Fuel School: Phase Separation in Ethanol Blended Gasoline When possible, use non-ethonal gas (like high test premium gas). And, do install fuel / water seperator "filter" system as well.

Hope these help as well...
 

Georgesalmon

Lieutenant Commander
Joined
Apr 14, 2012
Messages
1,793
Re: 97 120 force (smokes 5 packs a tank)

If you do decide to replace any fuel hoses, please use marine grade US Coast Guard approved hose for the safety of yourself, family and friends. Don't use auto hoses just because they are cheaper. Marine grade hose is fire resistant and has less permutation of gas through the hose. It costs more because it does more for your safety.
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: 97 120 force (smokes 5 packs a tank)

It is not a "three banger"--It is a four cylinder, two cycle, non oil injected engine. For oil, mix ANY brand TCW-3 outboard oil in the gas at 1 pint per 6 gallons gasoline.

You don't say where "here" is but if you have a Wal-Mart, oil can be found there as well as at other big box stores.No need to buy the expensive branded oil AND, For example, Wal-Mart oil tested as good as or better than some of the branded oils.
 

bentle

Chief Petty Officer
Joined
Aug 2, 2011
Messages
492
Re: 97 120 force (smokes 5 packs a tank)

I think he meant three fins, on the prop. Just sayin.
 

sightsrv

Petty Officer 3rd Class
Joined
Nov 9, 2012
Messages
82
Re: 97 120 force (smokes 5 packs a tank)

Sorry Frank...Its 3 blades, fins my lingo not so good sometimes.
 

sightsrv

Petty Officer 3rd Class
Joined
Nov 9, 2012
Messages
82
Re: 97 120 force (smokes 5 packs a tank)

Thanks Batman.
Do have the saver bar..Heres how much of a novice I am. 1 sorry about "banger". Its a 3 fin, blade..I cannot find any number or anything else on the prop. Best I know its same one came with the boat. Am I missing something? Its not on the prop itself? I know should take a harder look before asking dumb questions. Havent even took off the motor cover. "mercury gas filter" is this under the motor hood? . I see ya put the sierra between tank and merc filter will do the same.

All the hoses still look brand new and there is no trace of any kinda leak around the motor, transom or body of the boat. It realy does look like it just came out of the factory. Prop, will only be fishing & "exploring" anywhere can put it in the water. I guess mostly exploring ya know? Dang ethonol gas is the only gas in this county and close by counties..Wake County , NC. I got the stablizer like ya said and its in the tank. Stay-bil if spelled right.

Please let me know your thought on filter and prop. Cant thank ya enough for your help.
Try add a link to pictures. Thanks Much Batman!!!!

http://sdrv.ms/V0547n

Just noticed prop picture isnt in it. If ya want a pic of it will do.
 
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