Bogging under full throttle

[77searay197]

I put a 4.3 vortec motor in my 180
bowrider (Yamaha sterndrive) with a 1409 carb that I had bought on eBay. I did some research and put different jets and rods in it but if I try to give it full throttle it just wants to bog and only does about 30-35mph since I can’t give it full throttle I’m going to recheck my timing when I’m on the water tomorrow but do I need to mess with my jetting/metering rods more? Or maybe the secondaries aren’t opening? I bought a digital advance timing light and I’ve never used one of those before so I gotta get it figured out too. I pulled a plug and here’s what It looks like.

 

[Bondo]

Ayuh,...... take away it's internet connection to stop bloggin',....

But for yer boggin' issue,.....
My guess is, it's runnin' outa fuel, 'n if ya dump the fuel filters contents in a clear jar, yer gonna see all sortsa junk, besides fresh clean gasoline in it,.....

 

[77searay197]

Im kind of thinking it’s running lean too. It’s got a new water seperator filter and fresh gas in it. Maybe jetted too lean? It’s got a new fuel pump too

 

[77searay197]

Here is the way I set it up. I kinda wander how long the carb sat since it’s a used carb I bought.

 

[jimmbo]

Is the air valve over the secondaries opening too soon/too quickly, or not opening at all? Are all the metering rod pistons free to move?

One of the problems of buying a used carb, is you don't know what butchering was done to it.

 

[77searay197]

I can’t really tell because I have been in the boat by myself. It’s gotta be under a load for them to open doesn’t it? I think metering rod pistons are fine. I noticed it looks like maybe I had a little fuel leaking out of the vent. Should I just have it rebuilt? I checked the float level when I put the jets in and it was correct. My fuel pump doesn’t have a spot for a vent even though it’s a electric Marin pump. If I made a line go from the vent to the spark arrestor would that be ok or do I need to figure out something else?

 

[77searay197]

I had the carb rebuilt and it runs a hair better but I can tell it’s still running lean. I have the 1488 calibration kit but does anyone know which metering rod is a step richer than the 1461? I’m a newbie when it comes to all this jetting and tuning stuff on a boat

 

[77searay197]

I also have the accel pump on the top hole. Not much diff reallly that I noticed between top and middle hole

 

[Bondo]

I have the 1488 calibration kit but does anyone know which metering rod is a step richer than the 1461?

Ayuh,..... Off-hand, Nope,.... Which ever is a tiny bit smaller,......

Here's the Bible for the AFB carbs,....

 

[jimmbo]

Depending where you need the enrichment

Cruise/Power Emissions Part # .057" x .049" 1437 .060" x .057" 1440 .062" x .052" 1441 .063" x .037" 1442 .063" x .047" 1443 .065" x .037" 1444 .065" x .047" 1445 .065" x .052" 1460 .065" x .057" 1461 .067" x .049" 1462 Cruise/Power Emissions Part # .067" x .055" 1463 .068" x .042" 1446 .068" x .047" 1447 .068" x .052" 1448 .068" x .057" 1436 .070" x .037" 1449 .070" x .042" 1450 .070" x .047" 1451 .070" x .052" 1452 - - - Cruise/Power Emissions Part # .070" x .057" 1418 .071" x .047" 1453 .073" x .037" 1454 .073" x .042" 1455 .073" x .047" 1456 .073" x .052" 1457 .075" x .037" 1458 .075" x .042" 1419 .075" x .047" 1459

 

[77searay197]

Well it’s only when I try to hammer down it bogs a little. If I take off normal and just cruise it doesn’t really do it. Maybe try the 1460 first and if that doesn’t help then maybe if that doesn’t do it try the 1443 since that’s next from 1460 in my kit?

 

[77searay197]

Well I tried the smallest metering rod I have and although it’s a lot better when I get to around 4K it starts spitting and sputtering like it’s running lean still. Should I put the next bigger jets I have in it and then try it again? And would I need to change both jets or just the secondary jets? It takes off well and cruises well but when you wanna get the top speed out of it then it starts to stumble

 

[Bondo]

Ayuh,..... Did ya click on the link I posted,..?? All of the answers to yer questions are answered in there,.....

It's where I educated myself on these wonderful carbs,...... Really,....

 

[77searay197]

I didn’t even see that or what jimmbo put for some reason I’ll take a look

 

[77searay197]

I took the top of the carb off because I was going to put bigger main jet in and I started looking and the person who I had rebuild my carb put the primary and secondary backwards smh. So I swapped them around and put in the original metering rods I started with. I’ll take it out this weekend and see what I come up with. Maybe now I’ll have to do a little metering rod adjustment if that and hopefully it will be good