260 wont rev over 6250?

[jas638]

ok rigged up the spare motor(1993 stock numbers matching50-75hr? 260) while the other goes to jsre . starts and runs like a champ! only issue is motor seems to not have much up stairs. i am running a new 14.5x28 triton that should put me on 7000-7250 no problem. boat gps read read 80 tach read 6000. had less than 3/4 pedal down thought gonna hit 100.put the pedal down the motor rev went a little more to 6250 gps read 85 that was bout it. i would run out of runnin room and have to get off it. it is on an offshore ridgeback 20inch.my other motor went 7250 96mph with a 28p no problem. all new gas supply to rule out. other than that could it be the rev limiter? it dosent sound like its hittin it. the motor is singin nicely just not over 6250? any advice is appreciated:thumbsup:

[johnnyracer]

RPM too low for a rev limiter. Does it even have a rev limiter still on it.? What ECU ? 93 original would be external tpi and limiter on top , back of block . Digital would be internal limiter. Is this the same electronics as the other motor ? Did you run this same prop on the other motor?

[jas638]

has a digital box,i will check i think its a A48. same electronics i believe.no the prop is different. i ran a 14.5x29 on the other motor.

[Jay Smith]

Injectors may be fowled and running rich on top side. Also make sure the timing is advancing ALL the way at WOT sometimes the wiring from the trigger can become ridge with age and will nopt let timing advance all the way.

just a suggestion,
Jay

[jas638]

thanks jay, will check it. gonna put the other in the box today. should go out this week!

[Jay Smith]

I'll be looking for it ..........If possible make it late in the week I will be at the races next weekend...

Thanks,
Jay

[Dave Strong]

Make sure you have full opening of throttle plate using the foot throttle. Just another thought.

Dave

[jas638]

yup checked for full open and full timing both are good. have to say motor starts and runs crisp.no carbon on the exhaust, just has no pull above 6000. my cousin pulled away from me with a 225 promax. we were both runnin 28p .

[mercman~]

make sure that your running correct -suppressor spark plugs with digital ecu.

[Dave Strong]

Looks like Jays injector suggestion could be the problem. Maybe try a plug cut to see if your super rich.

Dave

[jas638]

i have to say cruised around made a couple of passes and sucked full tank -dry .30gal. i looked at the gauge and the needle was layin on e and not movin. i headed for the dock real quick. my other motor got better gas mileage. only was out for bout 1.5-2.0 hrs. and and sat and drifted for at least a 1/2hr. gonna try a different set of injectors.:thumbsup:

[K-Dawg]

God luck I cant get mine to rev past 7200 with any prop.

[jas638]

went out tonite tried a different prop one that i spun 7250 on my other motor to rule out prop.same result 6250 85 mph gps. gonna try a different set of injectors. any other thoughts?

[Juggernaut]

injectors are a good start. i had a similar problem on my 1993 245 carb this summer. it wouldnt run above 6500rpm. tried everything from a 30p to a 24p and had no change. turns out there was a coil that had gone bad and the motor was down a cylinder. the odd thing is, even at idle, it was smooth, and had no hesitation. changed out the coil and now shes turning 7200rpm. so check your injectors, and make sure your ignition doesnt have any problems like mine did.

[jas638]

well tried the spare set of injectors these were cleaned and flowed by brucato. same result ,6000-6250 tops. same result with a passenger . figured i would put a little weight in her and see how it went. same as if i were alone. i did notice the gas consumption wasnt as bad with the injector swap ,so at least thats a plus. i am noticing that there seems to be like a lack of power getting up on plane? gets up ,just dont seem to have that raw take-off power. guess its on to the coils. how can i tell or test to see if one is bad? besides swappin them out one at a time? any suggestions are appreciated. thanks,john

[John Richied]

It probably won’t fix your problem however it will ensure the trigger arm goes to full timing every time.
I added a spring… to make certain that happens.

[jas638]

thanks john,thats a really cool idea. looks factory ,bet it helps response too.i am getting full timing i should have noted that was the first thing i checked . i was hoping that was the problem would have been an easy fix.

[stvhelm]

when changing powerheads sometimes you have to check the gas pedal pulls the throttle open all the way. I cant tell you how many times Ive seen that get over looked.
If you're going through that much fuel its possible the vacuum hose or fitting to the ecu is clogged or broke and the other thing that will cause rich is the air sensor in the block is bad or not connected.

[Propster]

I had a bad plug on one of my 245's and it did not rev up. Have you tried another set of plugs?

[jas638]

hey helm ,hows it goin? thanks for the info. i did in fact check for wot,and pulled the cover off the ecu checked the tygon and the barb .clean and clear. the motor actually runs super clean. if you reach up inside the offshore leg wipe yur hand around it will come out clean with very very little carbon on it? is that good?
as far as the plugs those i could change and see before i get into the coils. does anyone have any info on how to test coils? properly. please reply,thanks ,john.:thumbsup:

[Dave Strong]

Have you got a DVA?
As stated above try a set of plugs if you haven't already, got burned by plugs that looked fine but a new set cured a similar issue.

Dave

[jas638]

yes dave i do, and i will be changing the plugs for sure. weather is crap for today and tomorrow -rain . wednesday i will get some seat time and try it. thanks for the input guys i really appreciate it!!! i will update ya!:thumbsup:

[jas638]

I had a bad plug on one of my 245's and it did not rev up. Have you tried another set of plugs?

hey propster,changed all six plugs. the motor went from crusing at 6000 80-82 to 7000 grand instantly the gps instantly went to 90plus it was real snotty out weather wise,not the best day to top end her. after all i wanted to live to report back on the fix.LOL. i am sure she will give me even more sure felt like it. so guys there you have it ! PLUGS were the problem , didnt really think it could be that obvious but sure was a cheap easy fix!!!! THANKS to everyone who shared their ideas to help me!!!!

[John Richied]

cheap easy!!!! :smiletest:
That’s the way we like it! :thumbsup:

[Dave Strong]

hey propster,changed all six plugs. the motor went from crusing at 6000 80-82 to 7000 grand instantly the gps instantly went to 90plus it was real snotty out weather wise,not the best day to top end her. after all i wanted to live to report back on the fix.LOL. i am sure she will give me even more sure felt like it. so guys there you have it ! PLUGS were the problem , didnt really think it could be that obvious but sure was a cheap easy fix!!!! THANKS to everyone who shared their ideas to help me!!!!

GOOD DEAL, So often we start looking for a complex fix and overlook the simple and baisic things.


Dave

[Propster]

It is always best to try the easy stuff first.

Too easy to overthink it. It has happened to me twice where plugs were not firing when they looked fine.

The last time it cost me. I thought it was not revving up because of timing. I added 2 deg advance and changed the plugs. The plugs were the problem, not the timing. Got the rpm back and it ran great until it detonated because of the over advanced timing. Meltdown - DOH!