Clean Carbs Today - needle/seat question

So, today I cleaned the carbs on my 82 750 Seca. Everything went exceptionally well. Got them all back in and bottoned down wihtout a hitch. They look FANTASTIC!! However, I tried to start it and no-dice (bike was running before the cleaning). I opened the float drain screws one at a time and found out the carb 2 and 4 were totally dry. I was able to get the float off of carb 4 wihtout removing the whole she-bang to find out that the needle was sticking in the seat. Pulled the floats, needle, and seat - cleaned them again, and now #4 is flowing fuel pretty well.

I don't think I have ever seen a needle refuse to OPEN - usually, it's the other way around.

I will have to pull the whole carb bank off to get at the number 2 needle and seat, which I will probably do tomorrow (if I have time).

Question - what should I be looking for to ensure that all needles/seats are operable BEFORE I go through the trouble of stuffing the carbs back onto the bike? What's the trick?

 

There isn't any "trick" to this .. you have to ensure your float valves are both sealing ... and ... sealing with the fuel level within the design limits of the system.

If you fill the carbs and they don't overflow you can be sure the needle valves are sealing. If they seal but the level is wrong .. as guaged by a clear tube connected to the drain and held up to the side (a la manual) then you know that the tang needs adjusting. This is really important .. don't skip this step ... just stay with it, painful as it may be, unitl you have them all very close (+/- 1mm) within the limit.

That way when you move to the next phase of tuning you can just cross off float levels as a potential source of trouble.

Stay with it and get it right.

 

The trouble was that needle #2 was not opening at all. However, I check this morning and the bowl had fuel in it, when the hose was used, the float level seemed to be spot on (for now). I hope this is the end of the carb trouble.

 

One extra step I take is to polish the float pins with 1k to 2k wet/dry, or, even the scotch bright pad you would use on the throttle slide bores.

It only takes a tiny bit of corrosion to cause a hang up.

 

additionally, roll a bit (1X1) of some 1500 grit REAL tight, and put it inside the "pin-bore" of the float, polish away.

Sharpen a wooden golf "TEE" and ream the seat lightly, for a good polish.
Some spin a "Q-Tip" with polishing compound in there, with a Dremel, but then you'd have to clean-up all that residue. . .

+1 on wet-setting the floats - ESPECIALLY if you mixed up all the floats and pins (like my buddy did to my Venture carbs :evil: ) You kept them segregated, right??

 

Kept them separated - did one carb at a time. I think something just got hung up because it was so clean and dry, but things seem OK now. I ran the bike for a while this morning before work. It seems to run well and revs just fine, very responsive and returns to idle just as expected. I may have detected an oil leak, but I'll track that down later.

Time to look at the front tire/forks/bearings/brakes/etc. so that I can finally take this baby out for a ride!

Then time to get it inspected/licensed - She'll be on the road soon.