checking and setting carb float hight????

[SiiCHo]

ok, so i know there is about 12983752934857293845712834 threads on tuning carbs, but with a search i had little luck on the topic i need help on. i just put a brand new PJ34 in my 84 250r and when i opened the tank valve, fuel started to drip from the bowl overflow line. i opened the bowl and bent the float tang to alleviate this issue, but i want to make sure i didnt bend it too much. ive read how to do the float check, but it doesnt make sense to me. i get the concept, but where do i attach the clear line? if i put it on the overflow stem, it wont do anything (unless its overfilling), and how would i attach it to the 17mm drain bolt hole? those are the only 2 things on the bowl... help please???

[barnett468]

Hello


If you saw that test on the site it was posted by either me or Tri Again. Unfortunately it only works on carbs that have a float bowl drain screw. If yours doesn't you can drill and tap your drain plug with a temporary fitting then put a screw and gasket in it after wards.

[SiiCHo]

I figured it out. I had to make a plastic piece to thread into the 17 mm hole, then attached the line to that. It worked, im even with the carb body, i got lucky on the first try.

[yamaha225dr]

You have to attach the clear hose to the overflow stem on the carburetor bowl. The problem with that is every Keihin carburetor I have seen does not have a drain screw on the bottom of the carburetor. With carburetors like that what I found to work best is using a piece of clean hose, attach it to the fuel inlet on the carb and with the bowl off, slowly blow into the hose with your mouth and push up on the float until you can't blow through the line anymore. Then check to see where the float is positioned. You want the float to sit level when the needle valve is seated. Your float has a seam running horizontally down the side, I used that seam and adjusted the float height until it was running parallel with the bottom of my carburetor.

[SiiCHo]

I guess that would have worked too, but its good, now on to jetting.... She wont idle.

[fastatc70]

You have to attach the clear hose to the overflow stem on the carburetor bowl. The problem with that is every Keihin carburetor I have seen does not have a drain screw on the bottom of the carburetor. With carburetors like that what I found to work best is using a piece of clean hose, attach it to the fuel inlet on the carb and with the bowl off, slowly blow into the hose with your mouth and push up on the float until you can't blow through the line anymore. Then check to see where the float is positioned. You want the float to sit level when the needle valve is seated. Your float has a seam running horizontally down the side, I used that seam and adjusted the float height until it was running parallel with the bottom of my carburetor.

Putting your mouth to any fuel line is crazy and not recommend!!

Them right way is to find the measurement from your bowl seam to the float.


Or the float has a casting seam and that seam will be parallel with the bowl seam. Note- where the float tang touches the needle there is a spring loaded button. The button and tang should be touching not depressing the button. That is why the pic is showing the carb with the outlet down. If the carb is upside down the weight if the float depresses the button giving the wrong measurement.

[SiiCHo]

Cool, thats good info! Thanks
Update
Stock jetting was
Pilot 55
Main 152
Needle clip top

Wouldnt idle, choke made it worse, lots of smoke when holding the throttle to make it idle. Reved but with hesitation at the top end
Dropping the pilot to 50
Dropping the main to 150
Leaving the clip at the top

Its worth noting that im at about 5200 ft above sea level in my garage and its about 95 degrees outside. Ill update after its back together.

[DasUberKraut]

Is there a link for this method?

I'm tired of dumping gas trying to figure this out.

[barnett468]

Hello siCHo

I figured it out. I had to make a plastic piece to thread into the 17 mm hole, then attached the line to that. It worked, im even with the carb body, i got lucky on the first try.

Very cool, can you post a photo of the plug you made so others [and I] can see what you did as others might want to do the same? You can alson hack o few off and advertise them for $6.00 a piece, lol.

[SiiCHo]

Well, she almost idles, just a little too low to self sustain. Gonna drop the pilot 1 more size. She revs like a beast, no issues there, at least not in neutral, we'll see what happens under load

[SiiCHo]

Hello siCHo






Very cool, can you post a photo of the plug you made so others [and I] can see what you did as others might want to do the same? You can alson hack o few off and advertise them for $6.00 a piece, lol.

Yeah, later i will, its crude, but did the job.

[SiiCHo]

Here some pics of the adapter i made. The kit came from pepboys, just a generic tube adapter kit. I had to sand and heat the end to thread it to the bowl. Leaked like all hell, but did the job

[barnett468]

Hello



If you have sustained tempos of 90 degrees you need to run a 9 plug not an 8.

Ride bike around through all rpm ranges with a new white plug for 30 minutes then do a do a plug chop in 5 th gear [not 6th] while going up a mild grade if possible.

Can you post photo of plug?

Do not use a flash!

You will probably end up around 45 pilot and 145 main with a 9 plug.

If your engine is stock or modified and compression reads less than 170 on a good compression gauge you should mill your head and correct squish band until it is a between 160 and 170 for 93 - 100 octane gas if you plan on continuing to ride it at that elevation. It will ping it's brains out on pump gas if you ride it at sea level, lol.

The compression at sea level should be 170, you loose 5 psi for every 1000 ft in elevation which means if your bike is stock your compression will only be 145 at best and is more likely 130.

[yamaha225dr]

[QUOTE=fastatc70;1238279]Putting your mouth to any fuel line is crazy and not recommend!!

Them right way is to find the measurement from your bowl seam to the float.


Or the float has a casting seam and that seam will be parallel with the bowl seam. Note- where the float tang touches the needle there is a spring loaded button. The button and tang should be touching not depressing the button. That is why the pic is showing the carb with the outlet down. If the carb is upside down the weight if the float depresses the button giving the wrong measurement.[/QUOTE


Next time before posting a reply how about putting your comprehension skills to work! I clearly said a "Clean piece of hose".

[SiiCHo]

The engine has about 6 hrs on it since rebuild, im running a 9 plug, 91 pump gas. It kind of idles on the 48 pilot, im just having trouble getting it stable. Its fine at about 1600 rpm, but when i drop it to spec (1300) it will hang for a second then fall and die. I may have to order a few more jets, 48 is the smallest i have on hand. Ive heard all you guys say to set the air screw 2.5 turns out, but my manual says 1 3/8... Im finding that it needs to be about 1.75 to 2, and the idle set is almost all the way out. Any input?