70HP MERCURY BLUE LOSE POWER

[hqspeed]

:'( i have a 70hp blue band MERCURY . i took it to the boat shop as it was lacking power at full throdel. they have now told me after having it for 2 weeks that the idel seals are worn . they also said it loses spark on the no 3 cylinder at full rpm. the reason i took it there was i put it on the water starts fine runs well,up untill about 1/2 throdel then it seems to starve for fuel . it only dose it after about 1/2 throdel. after i cut the throdel on and off a few times fast it took off like a ripper. went well then i cut rpm back a bit and it whent back the same after 1/2 throdel.
i hope someone can steer me in the right path i dont have 100% trust in the boat shops all they wanted to do was sell me a new 50hp motor but i just dont have the money for that at the moment
regards hqspeed:'(

 

[tashasdaddy]

Re: 70HP MERCURY BLUE LOSE POWER

it sounds to me that if the carbs, have not been cleaned and rebuilt, you may have some restriction in the high speed jets. another item to address is the link n sinc, of the electronics, and carboration. i don't know what idle seal are, unless carborator gaskets. here's a link on how to do the link n sinc.

http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=36;gtid=1114512

 

[quilter]

Re: 70HP MERCURY BLUE LOSE POWER

sounds you may have a switch box or a stator going bad, you need a dva meter to check it otherwise changing parts gets too expensive. low end sounds ok, may be a switch box cutting out. or high speed section of stator is going bad.

 

[hqspeed]

Re: 70HP MERCURY BLUE LOSE POWER

out of the water in gear we get full revs but once in the water and we get past the 1/2 way mark the engine seems to loose all power and stall

took it to the shop and they changed all the plugs and said it would not idle lower than 2000rpm but we have adjusted the throttle and have it at about 800rpm now they said it is not worth fixing and to buy a new one of them but $7000 + i just cant pick of the tree at the moment.
are there any links with diagrams on how to do the tuning on this motor.
is there any way of testing the coil packs and ecu to see if there faulty without going out and buying expensive tools.

hope someone can help me out here going to the coast in 2 weeks and paddle power is just not an option
regards hqspeed

 

[hqspeed]

Re: 70HP MERCURY BLUE LOSE POWER

also will red band 70hp electronic parts fit 70 hp blue band motor ie coil packs ect

 

[Laddies]

Re: 70HP MERCURY BLUE LOSE POWER

Don't free rev a engine it will eat a reed. You are right the only think common to 1 and 2 is the carb as reeds only function at idle and lowspeed. First find anouther shop or do the job youself you seem to have a better understanding of the engine than them. It's not a difficult job if you have a manual