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Discussion Starter · #1 ·
i got a '71 sl350 k1. i want to add manometer ports to the keihins. has anyone done this? there are many potential plugs i could remove and add brake bleeder nipples.
 

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It is true that some PW 24 carbs on the SL 350 K1/K2 models do have a plug on them.... I'm NOT certain the location would be correct, (pix might be helpful here) but it should be located somewhere between the carb slide and the intake valve (and I can't remember exactly where that plug is located)....
I believe that a "brake-bleeder" screw would hardly be the optimum set-up for mounting on the carb..... They require a sufficient depth of material to machine an appropriate "pocket" and seal on a taper, (unlikely you'd find that much depth in the thin-walled carb body), and they are usually cross drilled in such a manner that they would likely leak the vacuum you are trying to measure even if they could be mounted on the carbs....It is possible that machining the pocket directly into the head would work, however, I personally wouldn't do it.....
Wouldn't just drilling and tapping for a bolt or metering tube, or perhaps using the plug port (if it is in the correct location) be easier?
 

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Discussion Starter · #3 ·
i will have to drill out one of the block off plugs or in the head side flange. the bleeder nipple is the best thing i can think of, as the manometer i plan to make will be 1/4 or 3/16 tubing, and small diameter is key so i can put a bolt in when not in use.
 

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Discussion Starter · #5 ·
that is an interesting location, but like stated, the 350 head is a lot thinner flanged. now to find the cool posts.
 

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Here is a picture of one that was done on a 350.

In this case it's a 5mm screw hole.



Here is the vacuum port I installed on my Suzuki T500 the other night.

Before




After

 

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Your second photo is MIA, Mike - check the code.......

I'm planning to add taps to my 450 this spring, after a couple of timing modes.

I'm going to get these, in 6mm format. I'm more comfortable tapping the larger size - a little LokTite, Bob's yer' Uncle.
Just leave the rubber plugs on for riding, hoses fit right on the nipple, no adapters or screws required.

 

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tbpmusic said:
Your second photo is MIA, Mike - check the code.......

I'm planning to add taps to my 450 this spring, after a couple of timing modes.

I'm going to get these, in 6mm format. I'm more comfortable tapping the larger size - a little LokTite, Bob's yer' Uncle.
Just leave the rubber plugs on for riding, hoses fit right on the nipple, no adapters or screws required.



That's a good idea too Bill. I just hadn't ordered the ports and plug caps yet and I had the screws handy. In the case of the 350, there is not much room so the -5's work the best I think. Although, I did use the -5's on the 450 and T500 as well because that's the screw size I had 5mm x 6
 

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I imagine it's not the most enjoyable tapping experience into that aluminum ??

That was a really convenient place there on that 2-stroker carb !!!!!!
I'll be interested in how your Morgans work with the 2-stroke.
 

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tbpmusic said:
I imagine it's not the most enjoyable tapping experience into that aluminum ??

That was a really convenient place there on that 2-stroker carb !!!!!!
I'll be interested in how your Morgans work with the 2-stroke.

Actually, tapping the aluminum was a problem at all. I did it with just a little squirt of WD 40 as tapping fluid and it went very smoothly.

It's interesting you mention the Morgans. I used them the other day and posted something about the readings being so low it's tough to be accurate. Since then, I've read the Morgan website and they talk about using the guages on a two stroke. Basically, you turn them upside down. I'm going to be playing with them some more tonight.

Morgan Carbtune
Operation
FAQs

.........

The manometer must be used vertically for a scale starting at 8cmHg (centimetres of mercury. 1 inch=2.5cm 1cm=0.4inches) and going to 42cmHg. Most bikes have readings higher than 8cmHg, but some bikes such as R-series BMWs and two strokes can have readings lower than this.

To get a reading below 8cmHg remove the plastic cable clip from the slot at top of gauge and insert it into the slot at the bottom. Push cable clip into slot from front of gauge. Hang the Carbtune Pro upside-down.

Ignore the scale figures. Zero will now be around 16cmHg on the scale but the full width scale graduations will still be 2cmHg. Absolute values are not important. Comparisons are important.

Q. Does the Carbtune work with 2-strokes?
It will work on any engine as long as it has these two points:
1) Somewhere to connect it. The connection will either be a blanked off screw hole or a stub for pushing on a rubber hose. The Carbtune comes with both 5mm and 6mm adapters for screw in fittings and a 5mm id hose for the push on fitting. If you engine has these fittings it should fit. Most two-strokes do not have any connection points although Suzuki triples do.
2) The readings are between 0cmHg to 40cmHG. No problem with 2-strokes.
 

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Discussion Starter · #12 ·
thanks guys for the links and the photos. i will still attempt to tap the top of the flange (aft of the slide) to hide the ports a little better; and not penetrate the head if i don't have to.

now to order some of those TwinMax's and reassemble the SL. anyone want to group buy some, as the shipping is $9.95/order? i could go M5 or m6, doesn't matter.
 

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here's how I did my XS650, short pieces of 3/16 brake line about a inch long drilled the intake track and JB welded them in, balance the carbs with a manometer then interconnect the two sides, a poor man yamaha YICS (Yamaha Induction Control System) don't see why it wouldn't work on these Hondas
 

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jayel said:
......then interconnect the two sides, a poor man yamaha YICS (Yamaha Induction Control System) don't see why it wouldn't work on these Hondas
Hmmm, let's hear more about that.
Would it benefit any twin??
 

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tbpmusic said:
Just leave the rubber plugs on for riding, hoses fit right on the nipple, no adapters or screws required.



Posted: Sat Mar 20, 2010 3:27 am
Those rubber blind plugs that block off the barb when not in use perish quickly and leak air. Best to remove the barb and fit a screw and washer.
 

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tbpmusic said:
jayel said:
......then interconnect the two sides, a poor man yamaha YICS (Yamaha Induction Control System) don't see why it wouldn't work on these Hondas
Hmmm, let's hear more about that.
Would it benefit any twin??
I can notice a difference on my 650, seem to smooth it out a little, best I can tell you is get a piece of hose and try it, the early 650's had port interconnects cast into the head and they made more hp than the later models

YICS stands for "Yamaha Induction Control System" which was designed by Belfast University and involves a long passage across the head just under the inlet manifolds with a bolt closing each end and a hole (small) into each inlet tract to promote "swirl".
 

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tbpmusic said:
jayel said:
......then interconnect the two sides, a poor man yamaha YICS (Yamaha Induction Control System) don't see why it wouldn't work on these Hondas
Hmmm, let's hear more about that.
Would it benefit any twin??
It should. My '70 Norton 750 that I had waaaaaaayyyyyy back had the same tube interconnecting the intake manifolds. As Leethal mentioned, they used to crack and had to be replaced occassionally.

By the way, here is the Morgan Carb Tune guages being used on a 2 stroke. It worked pretty slick.

Here is what the reading were when I started. No, those are not my hands, my wife came out to help out like she frequently does. :)



After fiddling around, here is what I ended up with.

 

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Discussion Starter · #18 ·
MNellis said:
a fellow nail biter i see? but alas, why are the banks different readings?
 

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Yup, what he said.

...and the nail biting comes from trying to get the Honda GL1000 to run right. :)
 
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