Wet Setting Floats - Seriously?

Been reading up on wet setting the float levels on my newly rebuilt Hitachis... Not a very elegant process. Anyway, saw that another forum member (tabaka) had made a gage of sorts out of aluminum to do a dry setting of the float heights to get them close before going thru the TEDIOUS wet set process.

Tabaka stated the spec for his gage was .63 inches (16mm). This was the float height from edge of carb body to top of float (with carb inverted). I had read somewhere else that the spec was 17.5mm (I wrote it down, but now I can't recall where I found it?)

Question: Is there a bonafide spec for measurement? And yes (Fitz), I understand that dry setting is not a substitute for wet setting, and that XJs and their carbs are NOT temperamental...

 

Yamaha never specified a dry float measurment, at least not in any service manual I have ever seen. Only a wet fuel level , they stress that one the most since final fuel level is critical for a proper running engine.

 

Thanks for the response. I'm really just seeking to minimize the number of times I have to repeat the wet set process to get them right.

Yesterday, after assembling the carbs, I put them on my "make sure they're level" jig, and filled the bowls with fuel. On the third "tang adjustment" they finally stopped leaking fuel all over my garage (new parts from rebuild?). Now the level in my reference carb is about 10mm below the edge.

Hopefully this afternoon I can get them right and get the bike started. Any bets on how many random tang adjustments it'll take me?

 

A couple of tips:

"Dry-operate" the floats and ensure nothing is binding or hanging up; this isn't the most precise mechanism, everything kind of flops about.

Before taking a "reading" drain/fill/drain/fill the float bowls a few times; "work" the float valves through a few shutoff cycles. If you're adjusting to the first reading you get, it will be frustrating.

Your adjustments don't need to be random if you're careful about what you're doing. The biggest mistake most people make initially is over-adjusting. If you bend the tang enough to know you bent it, you probably went too far.

Patience, ensure the rack is level in all directions when checking, and take your time.

 

Wet seting floats does not take many attempts if you measure carefully.
First time after carb assembly run a piece to blue painters tape across each bowl and mark where the proper level should be. With clear tubes installed fill the carbs up and mark the level on each bowl. The difference in the actual level and the required level is the ammount the float needs to be adjusted. A simple float measuring tool can be made with a ruller and a piece of card stock folded around it with a tab to measure float height. I have a inexpensive set of calipers that does the job. I can usually get them exact within 2 to 3 tries.

 

RickB,

What they ^ said especially the part about dry testing everything to ensure nothing is hanging. I bought a Aftermarket rebuild kit for my carbs and had one float continuously hanging until I read in a thread that if I turned the open part of the clip on the top of float valves (the OEM valves are completely closed) towards the airbox the valves would not hang...It worked.
Also, the Aftermarket valves I bought are longer than the OEM valves. I wet set each one individually. Thing is...on-off, on-off, on...DONE! Once you get them correctly set you shouldn't have to fool with them again...Well, until next time (LOL). Hope this helps.

Gary

 

Yamaha manual LIT-11616-04-85 Page 104, float height 16.0mm +/- 1mm.
Page 109 gives details and 110 shows the wet method.

I set mine at 16mm and never checked by wet method. I will get around to it one day but the bike runs fine.

 

I found that I was able to cheat when wet setting my float bowls by only screwing two opposing bolts into the float bowls just enough to be snug. I hooked up fuel, checked float levels with the clear tube, turned off fuel and drained the fuel line (lower it below the fuel rail) and I could quickly unscrew the two bolts and removed the now full float bowl. Set it on a surface where it won't dump, pull the pin for the float you are setting and adjust the tang then put it all back together.

 

In my experience I would fit new needle valves & seats before attempting the wet setting process.

 

The easiest way I have found to Dial-in the Float Heights is:

Conduct an initial Wet Test.
Select the Carb which provides the CORRECT Height level of is needing the LEAST Correction.
Using the Correct Level from one of the four: Measure ... Dry.

Duplicate the Dry measurement among the other three.
Wet Test.
Make minor adjustments as necessary.

 

Thank to all; great dialogue. Got the carbs dialed in and back on the bike this afternoon. I had also hoped to get the bike started (for the first time in over 20 years) this afternoon, but not so fast...