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a few months ago i posted i thought i have lost some rpm over the last couple years, so i checked compresion on my 500efi and was low, 140's. most on here said doesnt matter do a leak down test. for other reasons ive had to have the moter pulled. hallet did leak down test they said it did great? it was 8-11 percent. everything i read says thats a bit high for a babied motor with 150 hrs??? also they are reccomeding ahaving the fuel injectors removed, tested, and cleaned while its out???
 

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a few months ago i posted i thought i have lost some rpm over the last couple years, so i checked compresion on my 500efi and was low, 140's. most on here said doesnt matter do a leak down test. for other reasons ive had to have the moter pulled. hallet did leak down test they said it did great? it was 8-11 percent. everything i read says thats a bit high for a babied motor with 150 hrs??? also they are reccomeding ahaving the fuel injectors removed, tested, and cleaned while its out???
Nothing wrong with 8-11% on a cold engine. It would tighten up alot if performed on a warm engine but at the risk of getting header burns.
check the injectors, could be like these
 

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Resident Ford Nut
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as stated nothing wrong with 8-11% leak on a cold engine with standard rings ( non- zero gaps )

S CP
 

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thanks, will probably try injectors(amazing picture-hass). just cringed at $800.00 estimate.
$800 for what? New injectors? I thought those things lasted forever like a our carbs do :happy: I guess that needs figured into the EFI-vs Carb debate :)hammers
 

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Ain't Right Racin
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$800 for what? New injectors? I thought those things lasted forever like a our carbs do :happy: I guess that needs figured into the EFI-vs Carb debate :)hammers
Damn u dont miss a lick !! good one :cool:
 

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Nothing wrong with 8-11% on a cold engine. It would tighten up alot if performed on a warm engine but at the risk of getting header burns.
check the injectors, could be like these
That #4...kinda looks like me in the morning...how do i fix that:))eek:))
 

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i thought i have lost some rpm over the last couple years?
You think or you have ? Big difference.

Prob a good idea to have injectors checked since motor is out, which is easier to pull, which is cheaper, which is......


$800 to pull and haved flowed/check ? Must be a marina quoting that !!!!!!!!! Wholly crap !!!!!!!

Anybody ever check to see if fuel psi is correct at idle and WOT ?

140psi isn't bad assuming all 8 are very close to each other. Remember, These are low compression motors with 230,236 at .050 " HR cams.
 

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You think or you have ? Big difference.

Prob a good idea to have injectors checked since motor is out, which is easier to pull, which is cheaper, which is......


$800 to pull and haved flowed/check ? Must be a marina quoting that !!!!!!!!! Wholly crap !!!!!!!

Anybody ever check to see if fuel psi is correct at idle and WOT ?

140psi isn't bad assuming all 8 are very close to each other. Remember, These are low compression motors with 230,236 at .050 " HR cams.
no i havnt checked fuel pressure
i lost 200-300 rpm had my prop lab finished still down 200???
hallett is doing work they are sending injectors out for "blue printing" $825.00 removal, blue printing, gaskets, etc... hallett dont work cheap!!! compression was from 142-154, merc service manual says shoud bee 175. leak down test performed twice i assume cold out of boat cyl 1-11, 2-9, 3-11, 4-9, 5-10, 6-9, 7-8, 8-8 percent.
 

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a few months ago i posted i thought i have lost some rpm over the last couple years, so i checked compresion on my 500efi and was low, 140's. most on here said doesnt matter do a leak down test. for other reasons ive had to have the moter pulled. hallet did leak down test they said it did great? it was 8-11 percent. everything i read says thats a bit high for a babied motor with 150 hrs??? also they are reccomeding ahaving the fuel injectors removed, tested, and cleaned while its out???
I noticed you were having issue with timing indicator for tdc. It's either right on or needs fixed so it is...couple 3 degrees retard timing...from the indicator being off...and a little cam chain wear could cost a few rpm...

Does that particular deal have valve guide issues? I chased a rough idle...motor didn't sound quite right ....thing around for several hours...on my own rig....comp 224-230 leaked down ok...did a cylinder drop test..5 holes dropped 90 rpm 3-5-7 dropped 75 rpm..ran a running comp test....every once in a while #5 would drop 30-40 psi...just one time..pulled the head....#5 intake was pretty loose..bad intake valve seal messes with the mix for cylinder each side of it...

Have you checked actual top speed? As soon as you change the prop your rpm reference point is no longer valid as it applies to actual mph...if the prop slipped less it might drag rpm down a little......
but mph went up......and you went and fixed everything and rpm is still down...:)bulb
 
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