My mileage/hourage was so poor that I was on the verge of ditching these 660s. I had heard of this mod and thought what the heck, if it doesn't work I'll just pick up the replacement secondary bell cranks and take em back to where they were.
Well the mod works and the secondaries are timed perfectly. Both open at the exact same time (about 3/4 throttle) and the motor runs fine. The only problem I have is that the secondary squirters are still shooting fuel into the back barrels even though the butterflies are not open and I want to close the secondary squirters off.
I've got the secondaires opening so late now that I'm 90% positive that I can get away without a squirter on the back two barrels at all.
Question I'm posing is.................what would be a good way to seal them off so only the primaries are getting the accelerator shot?
I was thinking a small piece of wire about the size of the hole and some JB weld?
O.K. it's backyard hackage, but I am a backyard hack. As far as I know there aren't any squirters available that fit these carbs other than the ones that were made for them and are on there now, thus I'm stuck with the four hole version.
Or any other suggestions you may have would be great.
Thanks
Dan
P.S. The carbs work great before and after the mod. The only reason I'm messing with em is un an attempt to get a little better mileage out of em, but I would like to get away from the extra fuel puddling up in the secondaries due to the acc. shot if possible.
http://www.***boat.com/image_center/.../carb_mods.jpg
Dan i don't understand what you are trying to do.The squirter's at idle should not be dripping fuel.Have you checked your float level's lately?I'd check them first.Sound's like they are to high and the fuel is going buy your needle and seat.Just a thought!!!!
JIM
I might not be explaining it clearly, but if you could see the setup you would get it right away.
It's not at idle Jim.
When you touch the gas pedal the squirters do their thing. Since each 660 has four squirters, when you hit the pedal it gives all eight barrels a shot.
As you know, with a regular double pumper carb (or even a vac sec carb) it gives a shot to just the primaries.
Since the modification my secondaries don't open until around 5000 rpm. Basically that means you're shooting fuel into them and the butterflies are closed (unless you practically floor it that is).
That's what I'm trying to avoid. There's no sense in shooting a shitload of fuel into those secondaries when the butterflies aren't open.
I've got the secondaries coming in so late now, that the acc. shot isn't even needed on the back barrels. She's rolling real good by the time it hits 5000 rpm and it just rolls right into the secondaires nice n smooth like.
The 660s are pretty much an all or nothing proposition. Really just good for drag racing (idle to WOT) and that's about it. I'm trying to turn em into more of an every day type carb. If I wasn't so cheap I'd just go buy something different.
Before the modification my secondaries were opening just off idle (O.K. more like 3000 rpm). Problem was that meant at a normal cruise speed I had all four barrels open unless I was cruising at less than 3000 rpm. Fat chance on that one!
Oh yeah, and you know me..................can't leave well enough alone!
Dan coudn't you just adapt a two hole squirter to work? If not JB weld would work or some soft lead pushed into the rear holes would work also. Did you get the bottom worked out on the boat? If so how did she do?
I don't think the standard two hole squirter would fit out of the box, but might be able to adapt it to fit. I'll have to check that out.
Good idea incidently.
If not..........then I guess it's the JB or lead idea. Melting some solder into the holes was my back up plan.
Bottom work did the trick. We're all back to normal............Yippee.
I'll take a test and tune day here in the not too distant future. Play with some wedges, rideplate angle, shoe n shims etc. Can't have the old girl leaving anything on the table.
Thanks for asking.
Good to here she's flying again did you just straighten the problem areas out? Did you end up putting a little hook back in?
As you know, with a regular double pumper carb (or even a vac sec carb) it gives a shot to just the primaries.
This must be a carb I'm not familiar with.....
"Double pumper" means just that......an accelerator pump on the primaries and secondaries.
http://i.pbase.com/o4/59/462059/1/55...Pumper6503.jpg
You could just disassemble the actuator linkage of the secondary accelerator pump, the vertical bolt and nut with a spring on it.
Then it couldn't pump at all.
Yeah, I just read that and realized I messed up. Regardless of my mistake the double pumper isn't shooting gas into a closed set of secondaries like mine is now...........right?
I don't have two accelerator pumps. Just the one feeding both primary and secondary simultaneously.
Good to here she's flying again did you just straighten the problem areas out? Did you end up putting a little hook back in?
No hook. Straight as straight can be.
Dan, 660's are not double pumpers you have one accelerator pump and 1 squirter feeding the primaries and secondaries at one time, and 660's do not have progressive linkage so primaries and secondaries open at the same time thus the need for a shot of fuel on both ends at the same time, a douple pumper has two pumps and two squirters and feeds the primaries and secondaries accordingly to throttle opening.. With your modification the secondaries don't open immediately but you're still getting a shot of fuel that you don't need making it a rich condition which kills performance and mileage big time!.. The best bet is a pair of 1850 vacuum secondaries, setup right they'll out perform the 660's on your deal big time and be a lot easier on gas!.... Now if you want the ultimate setup!...
Dan, 660's are not double pumpers you have one accelerator pump and 1 squirter feeding the primaries and secondaries at one time, and 660's do not have progressive linkage so primaries and secondaries open at the same time thus the need for a shot of fuel on both ends at the same time, a douple pumper has two pumps and two squirters and feeds the primaries and secondaries accordingly to throttle opening.. With your modification the secondaries don't open immediately but you're still getting a shot of fuel that you don't need making it a rich condition which kills performance and mileage big time!.. The best bet is a pair of 1850 vacuum secondaries, setup right they'll out perform the 660's on your deal big time and be a lot easier on gas!.... Now if you want the ultimate setup!...
Precisely Art. Now why couldn't I say it that clearly? However, you're talking about me having to spend money$
I'll probably do something like that next year, but I'm on a shoestring budget this summer.
I realize that the extra cost in fuel would probably more than make up for the initial ca$h outlay for a different set of carbs and I was even trying to sell the 660s (for a pretty darned fair price I might add) so I could make the change. No takers though. Now that I've modded the 660s it would be even harder to sell em. Live and learn. The cool thing is I only paid $250 for the tunnelram and both carbs a couple years ago. I guess I shouldn't bitch.
Dan call me i have ???????602-448-9374
Kinda late to call now Jim. Took the youngen up to the carnival for a bit tonight. I'll give you a shout tomorrow?
Dan
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