US1 carb question

[Burke Kilgour]

Putting a set of WH29 carbs on the 330 ported motor and noticed the impact tubes are of the smaller variety. From your experience with these steel bore ported motors with carbs, will this be a problem leaning out in the top end?
I have a set of WH31's which apparently work well with a cross drilled intake, but the WH29's are brand new and the WH31's are in rough condition. The only difference I saw between the 2 carbs was the impact tube size and more holes in the butterflys on the WH29's.
:confused: :confused:

[us1]

I haven't run 29s on one but its really all about the venturi size. A smaller venturi can suck more fuel through a small tube than a larger venturi with a larger tube. I would run 96 mains and give it a try checking piston tops closely. PS the 29s are off of a 150 HP so they probably wont make as much power as the 31s. The fuel curve will be off on the 29s.

[Burke Kilgour]

Here's the difference in size of the impact tubes.
I remember reading on here somewhere that the smaller tubes could cause leaning out on the top end.
I'm going to do a search for that.........
Bore sizes are the same.

[us1]

Like was saying they are 150 carbs so they are not really the right choice. Although you can probably tune them to work. I had a set of 150 carbs I tried to use on a Mod-U motor once and they were 20 HP down on the dyno no matter what I did.

[Burke Kilgour]

What WH # were the best carbs on the dyno?
I have a set of WH46 carbs on my Mod VP motor, they are listed as BP carbs but came off my 89 200. I'd prefer to not take them off because that motor is running good now.
The WH31's don't show up in my books, what motor are they from?
I didn't notice that you had added the 150 part...........

[us1]

The 31s are good. they come from a 200. As long as you run slosh plates and breather tubes any 200 carb is good. Here is a list of 200 carbs. WH-3, 14, 15, 18, 20, 22, 26, 28, 31, 39, 46.

[Burke Kilgour]

I don't have slosh plates or breather tubes. Where would be a good place to get those? Are they a mod or available from Merc? I've seen the breather tubes in pics on here.............

[bits&pieces]

Hey not to be a buttinsky I couldn't find a wmh 29 in my service manuel? is shows a wmh 28 being a 135hp carb1993,and a a 30 1994-95135hp. skips over a 29? I run carbs on my 2.5 and always looking for somthing better? 20 and 22 work:cool:

[us1]

Hey not to be a buttinsky I couldn't find a wmh 29 in my service manuel? is shows a wmh 28 being a 135hp carb1993,and a a 30 1994-95135hp. skips over a 29? I run carbs on my 2.5 and always looking for somthing better? 20 and 22 work:cool:
All the carbs we are talking about are WH carbs.

[us1]

I don't have slosh plates or breather tubes. Where would be a good place to get those? Are they a mod or available from Merc? I've seen the breather tubes in pics on here.............
You can get the off of other old carbs. You can run without them but choppy water and turns will cause the motor to cut out. The BP carbs have them.

[Burke Kilgour]

John (or anybody else) do you have a set of slosh plates and top plates with the breather tubes kicking around you'd sell?
I also noticed while rummaging around through my carbs that all the lower HP carbs all seem to have the smaller impact tubes. Probably a good way to tell the "good" carbs from the "bad".

[popslavaz]

Burke Here are part numbers for Hi-Perf. carbs
Float baffle--#88368 six required
Rivet for baffle--# 17-88457 six required
Slosh (vent) tube fittings # 22-94090 four required per carb.
( Mercury part numbers)
POPS

[Burke Kilgour]

Thanks POPS, I was just looking at my BP manual and it looks like the lower elbow goes into the top of the float bowl and the upper elbow goes into the top plate near the middle.
Could you, or someone, take some measurements with calipers for the exact locations of the holes?
I may make the baffles myself, there's a pretty good shot of them in the BP maintenance manual. Probably a drive rivet to hold them in.
These are the carbs I have to choose from:
WH23
WH29
WH31
WH41
WH46 (on another motor though)
I'm leaning toward the WH31's because of what John has said.

[us1]

29 and 23 are both 150 HP.

[Burke Kilgour]

How about the 41's? They have the small impact tubes and small jets.

[Burke Kilgour]

Holy crap POPS !!!
$332.43 for all those parts from Merc !!!!!!!!!!! :eek: :eek:
WOW, I think I'm going to make all the stuff myself and buy some brass elbows at the hardware store. :rolleyes:
P.S. the P.N. for the baffles is 88369, not 88368

[Capt.Insane-o]

Holy crap POPS !!!
$332.43 for all those parts from Merc !!!!!!!!!!! :eek: :eek:
WOW, I think I'm going to make all the stuff myself and buy some brass elbows at the hardware store. :rolleyes:
P.S. the P.N. for the baffles is 88369, not 88368



HAHAHA! Cripes why does'nt that surprise me at all. There is about five bucks in materials there. it's not hard to make your own baffles and the rest of the stuff can be purchased at any good hardware store.

[us1]

How about the 41's? They have the small impact tubes and small jets.
I cant find anything on the 41s

[T-REX]

41'S are Mag II carbs...150hp, but actually made around 165-70HP...Tha venturi are a lil smaller...Go with tha 31's...they are 1988 200, 2.4's, and they work well on a 2.5...The better carbs bein a 15, 22, and best allround big CI carb tha 20's...22'z have better off bank punch, but 20's have lil better top end...U kan work with tha 20's and make them leeve( dragg'in), but it messes up tha cruise/midrange....JMO

[Burke Kilgour]

Anybody got any leads on where to find some 5/32" ID elbows? Press-in type with a hose nipple.
I looked around Ebay and the net in general and didn't see anything.
Probably used on some small engines and such.

[us1]

Anybody got any leads on where to find some 5/32" ID elbows? Press-in type with a hose nipple.
I looked around Ebay and the net in general and didn't see anything.
Probably used on some small engines and such.
You can pull them out of some old blocks.

[Burke Kilgour]

Looks to me that the fittings are bigger than the bleed lines (just from the pictures I have)
I think they're the same size as the feed to the enrichment solenoid on the bottom of the upper carb bowl. I have 3 of those, only 9 more to go...... LOL
That would keep the bowl vent on the outside the same as the drilled passage on the inside.
Could you take a look at the size of the elbows and let me know?

[T-REX]

I do az John said...Take them outta old blocks.....They work juss fine!!!

[us1]

Looks to me that the fittings are bigger than the bleed lines (just from the pictures I have)
I think they're the same size as the feed to the enrichment solenoid on the bottom of the upper carb bowl. I have 3 of those, only 9 more to go...... LOL
That would keep the bowl vent on the outside the same as the drilled passage on the inside.
Could you take a look at the size of the elbows and let me know?
I'll look today but I think they are the same size. The hose is the same size for sure.

[Burke Kilgour]

OK, that's all the convincing I need :D :D
I have some new 90 degree bleed fittings kicking around here somewhere too.
Thanks !! :)

[YELLOWSS]

us1 know his ****. he advised me when i went to carbs and hit the jetts on the money. Just listen, and do what he says. lol

roy

[YELLOWSS]

us1 know his s*&%. he advised me when i went to carbs on my bp, and hit the jetts on the money. Just listen, and do what he says. lol

roy