70 hp won't get to WOT.

[Dc19]

hey guys new to forums hope someone can help. i have a 1990 70 hp evinrude. its on a 24' pontoon boat that i purchase couple of weeks ago. it starts and runs good. when in water it dies from neutral to in gear. once u get in gear it runs very nice( i think). when control lever is wot it seems that motor is about 3/4. after some investigation, butterflies are not horizontal at wot. i messed with some adjustments on cam, roller, and throttle cable. something doesnt add up. if u adjust throttle rod on cam and lengthen throttle cable the carbs get close to horizontal, but then idle screw is all the way in an does touch. this is basically my problem. hope this makes some sense. thx

 

[Ridiculous]

Re: 70 hp won't get to WOT.

hey guys new to forums hope someone can help. i have a 1990 70 hp evinrude. its on a 24' pontoon boat that i purchase couple of weeks ago. it starts and runs good. when in water it dies from neutral to in gear. once u get in gear it runs very nice( i think). when control lever is wot it seems that motor is about 3/4. after some investigation, butterflies are not horizontal at wot. i messed with some adjustments on cam, roller, and throttle cable. something doesnt add up. if u adjust throttle rod on cam and lengthen throttle cable the carbs get close to horizontal, but then idle screw is all the way in an does touch. this is basically my problem. hope this makes some sense. thx

soounds to me like you need to do a "link n sync"...search it on this forum and you'll find info on it. but you really do need an OEM manual to do this procedure b/c it explains it better than any of us could...

 

[Dc19]

Re: 70 hp won't get to WOT.

thx for the tip. i have a manual, i will try the link and sync and post the results.

 

[Ridiculous]

Re: 70 hp won't get to WOT.

thx for the tip. i have a manual, i will try the link and sync and post the results.

good deal! i'm anxious to hear if it fixed the problem.

and it's not called a link n sync in the manual (not mine anyway). its called something like 'carb linkage timer base synchronizing' or something like that...

good luck...

 

[Dc19]

Re: 70 hp won't get to WOT.

you are right, looking at manual now, hopefully i can resolve problem over next couple of days. do u think rebuilding the carbs is necessary, its starts and runs smooth?

 

[jtexas]

Re: 70 hp won't get to WOT.

don't adjust the throttle rod (if by "throttle rod" you mean the rod linking the thottle lever to the cam, screwed into a plastic yoke). it has to be a precise length. The timer base has to move a given distance before the cam hits the roller, or else you won't have enough spark advance when the throttles start to open. She'll fall flat on her face.

There's a stop screw to control how far the throttle butterflies open.

Heads-up: you won't be able to judge how well she runs until you put the boat in the water & put a load on the engine. No point in revving it up on the muffs and its dangerous besides.

 

[Ridiculous]

Re: 70 hp won't get to WOT.

don't adjust the throttle rod (if by "throttle rod" you mean the rod linking the thottle lever to the cam, screwed into a plastic yoke). it has to be a precise length. The timer base has to move a given distance before the cam hits the roller, or else you won't have enough spark advance when the throttles start to open. She'll fall flat on her face.

There's a stop screw to control how far the throttle butterflies open.

Heads-up: you won't be able to judge how well she runs until you put the boat in the water & put a load on the engine. No point in revving it up on the muffs and its dangerous besides.

jtexas is right, don't adjust the rod.

but, jtexas, he said he already adjusted things, thus probably messing up timing of things.

best thing he can do now is follow the procedure in the manual, yes?

it will get all of that back in time, then the troubleshooting can go from there...

 

[Ridiculous]

Re: 70 hp won't get to WOT.

you are right, looking at manual now, hopefully i can resolve problem over next couple of days. do u think rebuilding the carbs is necessary, its starts and runs smooth?

i wouldn't rebuild the carbs just yet if it were me. reason being, 1) you said it starts and runs smooth 2) you've already noticed that the butterflies were not completely open 3) you played with the adjustments probably throwing things outta time.

so if it were me, i'd get that linkage all timed back up, get the valves open all the way, and see how it runs.

and do take jtexas's advice, don't judge it on the muffs either, that water backpressure makes a huge difference.

and also note, if it's spitting and farting, it's running lean, a very bad thing for two strokes, b/c a lean burn situation means lack of lubrication also, so do not run it like this for long!

good luck, keep us posted!

 

[jtexas]

Re: 70 hp won't get to WOT.

...best thing he can do now is follow the procedure in the manual, yes? ...

agree. I don't recall the throttle rod/yoke thing being included as a step in the link & sync (could be wrong, it's a lotta stuff I don't recall anymore ) -- so make an effort to get it back where it was. Seventies models, it's on 4 31/32 inch centers (if memory serves), I can't guess if that's correct for 1990.

 

[Dc19]

Re: 70 hp won't get to WOT.

thanks for the input so far, and yes the throttle rod described above was the one i messed with. i'm sure i got the timing all jacked up. is there a standard set length it needs to be?( length of rod). would a timing light help in my quest? im sure i will have more questions as i go. so again thanks again!

 

[Dc19]

Re: 70 hp won't get to WOT.

just read more posts my length question i think was just answered. thanks

 

[Ridiculous]

Re: 70 hp won't get to WOT.

thanks for the input so far, and yes the throttle rod described above was the one i messed with. i'm sure i got the timing all jacked up. is there a standard set length it needs to be?( length of rod). would a timing light help in my quest? im sure i will have more questions as i go. so again thanks again!

yes there is a legnts, it's 4 31/32" from the end of the rod to the face of the cam, but your manual will tell you that..

and yes you will deffinetely need a timing light to do the whole procedure...