Had to take the carbs off....just to see.

Amazingly enough, they are pretty clean inside. Still going to clean 'em up, but after the last couple of bikes it's refreshing to start with carbs that move freely. Even did the clunk test, and my carbs clunk!

Of course, I also may have found the reason the PO couldn't get it running. Here's a break down of the jets in each:
#1: both 120
#2: both 40
#3: one of each
#4: one of each, but opposite what #3 had.

All the tiny little jets in the float bowls are plugged.
#4 float was bent way outta shape
All floats are bottoming out on the valve seat way before the float valve can come close to actually closing.

I may be new to Yamaha bikes, but I'm gonna go out on a limb and say that maybe, just maybe the last guy in the carbs didn't really know what he was doing. 8O
I took some pics, I'll post em up later.

 

Amazing what some PO's do. It gotcha a good deal, though.

 

so one of them is right, right?

not sure exactly what you are saying here - but it sounds like maybe, possibly, your floats are upside down - with these carbs, it's an even easier mistake to make than screwing up the jets

 

Yup, one carb was correct for jetting, all others where off.

It's possible the floats are upside down, didn't even consider that. But...the little tang that actually pushes the valve up is bent way out. It actually looks like the floats where "adjusted" by just pushing on the actual float, instead of bending the tang like you're supposed to. I'll have to do some creative work with pliers and possibly a drift to get the float frames squared up again.

While I'm working on the floats, what is a good height to set the floats for an initial setting? I'm talking about before you button back up, the height from the carb body to the bottom of the float (with the carbs upside down).

Thanks!

 

Wow. Just wow.........

And this engine ran?

The proper "float height" is whatever float height achieves the proper fuel level in the carb bowl. For most models using the HSC32 carbs, that fuel level (as measured via the clear tube method) is 3mm +/- 1mm.

 

i believe it is 17.5mm - but best to use the clear tube method to be sure.

.

 

Len, I'm told the engine would start, but wouldn't keep running. I'm amazed it did anything!

I'll be using the clear tube to make sure, but as bad as they are I need something to use for a baseline. 17.5mm it is then.

Funny thing about these carbs: A number of years ago I was rather apprehensive about tearing into a single carb, much less 4. My last bike was a Honda Magna. In case you may not know, those are V4 engines with the carbs in the middle. After working on those carbs and all the linkages for throttle and enricher circuit these Hitachis, all in a row, seems downright simple in comparison. And I like the arrangement of the synch screws better on these as well, much easier to get at while on the bike I'm betting!

 

Miracles allowing Bikes to run with messed-up Carbs seem to happen quite often.

I bought a set of "Parts Carbs Off A Running Bike" thinking I could Clean them and have a spare set to sell somebody to get them going if they needed Carbs.

I had to remove the Main Jet and push-out the Emulsion Tube while extracting the Diaphragm Piston Assy., because the Needle was stuck inside the Tube.

 

Amazing what some PO's do. It gotcha a good deal, though.

 

Better check out the arrangement of the air jet up top (under the rubber vac piston diaphram), as most likely they may have some creative placement top-sidem too.

Pilot air jet goes in the forward-most hole (nearest the engine), and is the LARGER air jet (#225).

Main air jet goes in the center hole, and is the SMALLER air jet (#80).

Rear-most hole is for the air jet cover plate hold-down screw, which may or may not be present on your carbs---some used them, some didn't.

 

Sounds like a monkey tried to fix a television. I tore apart a small block Chevy once that had bearings installed like your carb jets, but it didn't run.

 

The air jets up top where correct, but I removed 'em for cleaning anyway. Thankfully the covers where all there too. (I think the covers help stabilize the flow, but that's jmho).

All the brass parts got a good soak in carb dip and came out nice and shiny clean. Have to go to parts store this morning and pick up some more carb cleaner and other supplies.

 

Sure enough, the floats where upside down! Now I'm boiling the float bowls, trying to unstick the drain screws. All four are stuck good.
Did a little searching and found this thread regarding the dry float height:
Setting HSC32 float height dry

I got the little jet in the bottom of the bowls nice and clean already, so once I get the drain screws fixed the bottom end is ready for reassembly.

 

The easiest way to get the stuck Drain Screws out ... is to use a SEARS Craftsman Hand-Held Impact Tool.

You have to "Doctor" the Bit to get it to fit the Drain Screw recess.
Have an assistant hold the Fuel Bowl against a firm object.
Some HEAT and several drops of Vegetable Oil helps.
Wear gloves.

 

for those that don't have assistants - i screwed the bowl to a board that i clamped to my work bench. held the bowl nicely - just gotta be careful not to tighten the screws too much or whack the impact too hard and damage the bowl.

 

3/8 drive cordless impact driver. Works awesome on the stuck screws and bolts on these bikes, and you don't have to have that assistant

 

I went neanderthal: Fire! Propane torch+10 seconds and I was able to get all four out. Cleaned everything up and used antiseize everywhere during reassembly. Not willing to let well enough alone, I had to reinstall and just see if she'd fire up.
Sure enough the old gal fired up! Ran pretty rough, and it'll obviously take some more work to get everything clean and adjusted correctly. I let her run for maybe 45 seconds then shut her down.
Got to thinking with the PO's version of carb work I bet the oil was fairly high on gasoline content. Pulled the drain plug and confirmed that. YIKES!! Definitely going to have to inspect bearing VERY closely when I get to that.
For now though, it's back to work on the forks and front brake system. Knowing she'll fire up though makes it easier to start sinking money into all those little things that add up!

 

Absolutely works great! Along with Kroil, it's almost miraculous.

 

Update for anyone who may search and find this thread:

17.5mm was just a bit too much for the floats on my bike. I set a couple at 17 and a couple at 17.5mm. The ones at 17mm worked out exactly at 3mm using the clear tube method. The ones that were at 17.5 wound up being at 4mm, which is right at the edge of acceptable. I took the float bowls back off and set them all at 17mm dry, which is 3mm using the clear tube.

Hope that may help someone else in the future.