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The_Fishing_One
09-08-2005, 01:42 PM
I have a 65 horse Envinrude-2 stroke O/B...

it starts up normal and all but i can only push it up to half of what it is capable of....

it will run all day no problem but no matter how i push the throttle forward it maxes out *at half throttle...

I know some of you might have read this before but:

the problem started the instint I jumped a wake and landed, I toke the cover off *and observed the machanic stuff and seems like the throttle cable is moving everything fine but for some reason the engine won't power up

here is the catch - in nuetural i can rev it up high and it runs good but in gear it won't do it??? *i am thinking my gears is *messed up? anyone can help me out? *it is a old motor/boat i don't want to spend big $$$ on it.......

SturgeonVirgin
09-08-2005, 03:54 PM
I have a 65 horse Envinrude-2 stroke O/B...

it starts up normal and all but i can only push it up to half of what it is capable of....

it will run all day no problem but no matter how i push the throttle forward it maxes out *at half throttle...

I know some of you might have read this before but:

the problem started the instint I jumped a wake and landed, I toke the cover off *and observed the machanic stuff and seems like the throttle cable is moving everything fine but for some reason the engine won't power up

here is the catch - in nuetural i can rev it up high and it runs good but in gear it won't do it??? *i am thinking my gears is *messed up? anyone can help me out? *it is a old motor/boat i don't want to spend big $$$ on it.......

check the coil(s). had the same thing on my old johnson 25 that did exactly the same thing. Under load, she would not pull more than hafl throttle, in neutral, no problem. Mech said he sees it a lot on older motors.

Chetco_Indian
09-11-2005, 07:28 AM
I second with Mr T coil I had the same trouble .You should have two coils one low rpm and one high.

The_Fishing_One
09-12-2005, 01:12 PM
how will you know if the coils are bad? are they costly to repair?

drstressor
09-12-2005, 01:43 PM
If I remember correctly, those old engines have a coil for each cylinder. So yours should have 3 (unless you have an old V-4). If a coil is completely gone, you won't get any spark to the cylinder affected by the coil in question. So just pull plug, turn over the starter, and see if a spark jumps between the electrodes. Coils usually fail completely when they go. The engine runs rough at idle and losses power because one or more of the cylinders stops firing. To test for a weak coil that is not putting out enough voltage to keep the plug firing at high rpm, you need a special meter that can measure high voltage at very low amperage. So you would probably need a shop to check that out for you in a test tank.

As far as I know, coils can't be repaired and need to be replaced.

johnniebfishin
09-12-2005, 07:40 PM
coils can be checked with a common ohmmeter they usually have a primary winding and a secondary winding measuring across the primary winding first then measure across the secondary winding. i usually remove the coils from the motor and check them with an ohmeter comparing the readings of each coils primary and secondary windings. usually one of the windings are open. they cant be fixed just buy a replacement.

drstressor
09-12-2005, 09:04 PM
So if you get infinite resistance the winding is bad? Makes perfect sense. I've only checked coil output with the engine running.

johnniebfishin
09-13-2005, 07:06 AM
ive had coil problems in the past with a 1976 johnson outboard. i bought the motor new back then also bought the service manual for it. the book usually gives the specifications for the coils resistance of each windings.so the resistance reading you get must fall within the specifications called for. yes infinite reading would indicate an open coil.

The_Fishing_One
09-14-2005, 09:33 AM
thanks guys i will grab my manual and check out the coils for sure will lets you all know the out come

thanks agian ;)

fenton_chris
09-16-2005, 09:44 AM
im going thru the same thing. i have 77 evinrude 9.9 it lost alot of horse pwer. i took it in to have it looked at. when i got it back it ran great again he said it was the plugs. but when i went to leave the lake it ran like crap again. then i was at hell hole past weekend. it ran the 1st night for a few hrs. still no horse power. then the next morning nada it wont start at all. cleaned plugs, checked compression, checked fuel for water, sprayed starting fluid in carborator and plugs noting ???. held a screww driver in cable it would sparkholding it close to the engin. but when either of the plus where in and grounded, almost no spark. in both cables even with the plugs switched. my dad was completly stumped(who knows more about motor then me). he said it should at least fire up. we think its the coils as well. $28 for new ones

fenton_chris
09-17-2005, 10:00 PM
replaced the coils. starts right up! 8) with power. also found out my motor isnt a 1977 its somewhere around 1975. now i just need a test run next weeknd. going to either loon, ice house or spaulding. ;)