Help me identify what engine I have in my new boat

alldodge

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The max a 350 will be able to suck in is 557 in race application at 5000 rpm
 

Rugglesworth

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The max a 350 will be able to suck in is 557 in race application at 5000 rpm
exactly so the 800 cfm is just way too big. I may just buy the new one and sell the used one. I'd like it to be more of a plug and play with no issues this summer.
 

Scott Danforth

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I fired her up yesterday on the fake a lake and it was set to idle at 1000 rpms. I tried to bring the idle down and by 900 rpms it just dies.
the current carb sounds like the idle circuit is plugged and you are only running off the main jets
 

Scott Danforth

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Volvo Penta put 715CFM carbs on stock block 350's from 1987-1994.

the AVS 2 along with the webber and the 1409 all are available as 650 CFM or 800CFM. since they have the secondary flap they only flow what the engine can draw.
 

Rugglesworth

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the current carb sounds like the idle circuit is plugged and you are only running off the main jets
Could be. It's an oversized automotive carb so I'm not sticking with it. I just want to slap the right carb on there, adjust and go boating which is why I'm leaning to just buy the new 1409
 

Scott Danforth

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get the stock carb, pull it apart, clean all the passages, install new gaskets, then adjust and go boating. out $50 max
 

Scott06

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so I got ahold of the previous owner and apparently he still has the stock carb and is going to send it to me next week so stay tuned. If it actually is the original carb, I am sure it will need a rebuild. I asked why they changed it. He said it was fine we just wanted more power and got it with the avs2. That carb is 800cfm which I believe is way too big for a base 350. I fired her up yesterday on the fake a lake and it was set to idle at 1000 rpms. I tried to bring the idle down and by 900 rpms it just dies. So I'll see what he sends me and then I'll post pics and go from there. Worst case I just by the new 1409. I have a couple of months before we hit the cabin for the holidays. Thank you all for the help so far
More than likely there was something wrong with the old carb. Sounds like if it wont idle idle passages are clogged or set too lean. at 1000 rpms you are into the transition circuit which supplies gas between when throttle gets past the idle ciruit and the boosters haven't taken over yet (around 2000 rpm).

Weather its a q-jet, AVS2, or 1409 they do it slightly differently but all have an air flap that only allows as much air as the engine is going to take.

On crate engines Merc uses a 750 on its 5.7 engines, other places like michigan motorz sells 1409s (600 CFM). On CFM calculators
https://www.summitracing.com/newsan...mImEsUtONlg-pPhNIgpz6zvABC2ONVXtZqsu9mScrlASv

shows you need 440 cfm....

Edit- i was typing as AD and Danforth were posting sorry for the duplicate info
 

Rugglesworth

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More than likely there was something wrong with the old carb. Sounds like if it wont idle idle passages are clogged or set too lean. at 1000 rpms you are into the transition circuit which supplies gas between when throttle gets past the idle ciruit and the boosters haven't taken over yet (around 2000 rpm).

Weather its a q-jet, AVS2, or 1409 they do it slightly differently but all have an air flap that only allows as much air as the engine is going to take.

On crate engines Merc uses a 750 on its 5.7 engines, other places like michigan motorz sells 1409s (600 CFM). On CFM calculators
https://www.summitracing.com/newsan...mImEsUtONlg-pPhNIgpz6zvABC2ONVXtZqsu9mScrlASv

shows you need 440 cfm....

Edit- i was typing as AD and Danforth were posting sorry for the duplicate info
I wonder why they'd supply a 750 on a motor that only needs 440 cfm? Either way the 1409 sounds like the way to go? I'm not sure if this guy will even stand by his word, whether it's the stock carb or not.... He's lied about a few things already so I thinking I'll just order the new one and see what he sends me. I can rebuild that and sell it to recoup some of the cost. That way I know I have a brand new carb ready to go. Considering the circumstances do you agree that's the way to go?
 

Scott06

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I wonder why they'd supply a 750 on a motor that only needs 440 cfm? Either way the 1409 sounds like the way to go? I'm not sure if this guy will even stand by his word, whether it's the stock carb or not.... He's lied about a few things already so I thinking I'll just order the new one and see what he sends me. I can rebuild that and sell it to recoup some of the cost. That way I know I have a brand new carb ready to go. Considering the circumstances do you agree that's the way to go?
Oh yeah it would seem he is full of chit. Unless it was a 2bbl carb then going to 4 bbl yes would expect more power. See what he gives you and go from there. if it is a q jet that is unmolested core then you have something.

for sure a new one will be bolt on and go, really probably depends on your skill set and finances.

I dont know why they use a 750 , the 4.3 merc crate engines have a 600 cfm carb. Again the air valve corrects for the displacement, I'm sure they have their reasons. truth is probably either a 600 0r 750 will work, but 800 on a stock 350 is getting way too big.
 

cyclops222

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Make VERY VERY SURE the throttle linkage will REACH and CONNECT to the new carb !!!!! Otherwise can be a long disaster. BEEN THERE.
Also make sure pushing down on the pedal WILL CAUSE the carb to open the throttle butterfly.
 

Rugglesworth

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Make VERY VERY SURE the throttle linkage will REACH and CONNECT to the new carb !!!!! Otherwise can be a long disaster. BEEN THERE.
Also make sure pushing down on the pedal WILL CAUSE the carb to open the throttle butterfly.
I thought it the 1409 was a plug and play for this motor. Why wouldn't it reach?
 

Rugglesworth

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So the carb should be arriving today. I. Assuming there's no reason to keep any if those spacers on there correct?
 
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