Carb 3 & 4 mixture screws do nothing

[NHVmaxpower]

Oops!:biglaugh:

Sorry man, I think I contributed to that:biglaugh:

I think it's just collective ADD and the forum following a normal "flow" of conversation.....

Then again we do have a Thread Hijacker Award:rofl_200:

I want that award: )

 

[NHVmaxpower]

Wow rusty you have 2 hijacked awards wtg lol

 

[infinity999]

Haha... I'll definitely post back and let everyone know how I mangled these things.

 

[infinity999]

I did a wet level check on carbs 3&4. They are way below the 16mm line. In fact, carb 3 is about 50mm below where it is supposed to be. I assume this would indicate a lean condition which is why the exhaust is not very hot coming out of this cylinder..

I am going to pull the carbs tomorrow and set the levels using some calipers I just purchased. Seems that the desirable level is 1.115 in. Any advice on this level? Looks like the casting marks proved to be very unreliable in my instance.

Thank you.

 

[dannymax]

I did a wet level check on carbs 3&4. They are way below the 16mm line. In fact, carb 3 is about 50mm below where it is supposed to be. I assume this would indicate a lean condition which is why the exhaust is not very hot coming out of this cylinder..

I am going to pull the carbs tomorrow and set the levels using some calipers I just purchased. Seems that the desirable level is 1.115 in. Any advice on this level? Looks like the casting marks proved to be very unreliable in my instance.

Thank you.

It's all in the wet level....try the 1.115" and verify with wet level, if it gives you 16mm - 17mm then use it for the others but check them too.

 

[infinity999]

Well the 1.115 didn't really seem to work at all for me.

What did seem to work was measuring .840 from the top of the tang on the float to the bottom of the float per Damon's video. With that adjustment at .840 the casting marks definitely don't line up. Worked on all but one of the carbs that is at .832 on the measurment. Apparently this is a very fine adjustment. The carbs all seem to be about on the money. I got lazy and hooked them up to the fuel line and cycled the ignition. I would hate to have to rack these back together only to have to take them apart again. I am going to double check and maybe make some fine adjustments tomorrow but I think I am about there.

 

[Rusty McNeil]

Well the 1.115 didn't really seem to work at all for me.

What did seem to work was measuring .840 from the top of the tang on the float to the bottom of the float per Damon's video. With that adjustment at .840 the casting marks definitely don't line up. Worked on all but one of the carbs that is at .832 on the measurment. Apparently this is a very fine adjustment. The carbs all seem to be about on the money. I got lazy and hooked them up to the fuel line and cycled the ignition. I would hate to have to rack these back together only to have to take them apart again. I am going to double check and maybe make some fine adjustments tomorrow but I think I am about there.

Didn't work because the wet check follow up didn't come out at MM's you're aiming for? What MM's did it give you?

Good news overall tho', keep us posted..

 

[infinity999]

To be perfectly honest I don't really remember what 1.115 was giving me, but it was way off. I believe it was way too lean..

.840 from the top of the tang (adjuster) to the bottom of the float was the closest. I connected each carb to the fuel line, did a wet check and they seemed good.

Put the carbs back together, and then back on the bike. Closing the mixture screw on carb 3 will make the bike stumble now. Carb 4 still does nothing adjusting the mixture screw so I did another wet check and it is too lean! Can't believe it.. Also, I checked carb 2 and it is a a few mm's too rich. I guess the only way to do a real wet check is to have the carbs on the bike. Is it common to have to remove the carbs 10 times to get this right? It is becoming not worth my time to screw with this anymore.. I imagine paying someone to set the floats shouldn't cost me too much..

 

[Rusty McNeil]

Man, I'd triple check that its definitely firing on all cylinders at idle, proper synch and all that. Then just let it go.

Theoretically they should all respond but sometimes they just don't.

If them doesn't respond so well just set it like the rest.

If its got no other nasty habits, the mileage is good, and the plugs look good I wouldn't over analyze it.

I'm not saying it can't be corrected eventually, but the "not responding" a/f screws aren't that unusual and you've done your due diligence.
I don't believe the float level would effect the a/f screw not responding issue?

Confession, one I could be crucified for!

I talk about wet checks but have never done one, once I know the seats are in good shape, the floats are all set the same, and the float needles are seating by knowing the bowl is full, the pump quits, and doesn't run again when I wait a bit and turn the key back on, I don't care what the wet check mm is as long as the mileage is good, the plugs look good and its running properly where the float level has an impact.
I have checked the floats to make sure they all float the same in a cup of gasoline before just to make sure I didn't have a bad one.

Another confession. I'm guilty of ONLY mechanically synching the carbs as well. My motion pro sucks as the mercury separates before I can finish the job.
My test once again is that if the idle is as low as I can get it and its running on all cylinders then synch is good enough.

Once its off idle synch becomes less and less critical as the difference in butterflys becomes such a smaller and smaller percentage of the overall opening angle of the butterfly.

All of the above is just my opinion and experience, some of it is unconventional wisdom for sure.

 

[infinity999]

I see what you're saying, but I would think screwing the mixture screw all the way in should do something..

 

[Rusty McNeil]

I see what you're saying, but I would think screwing the mixture screw all the way in should do something..

I agree. Back to synch, it could be that that cylinders butterfly is open just enough to be fueling itself off not just the idle circuit.

 

[dannymax]

To be perfectly honest I don't really remember what 1.115 was giving me, but it was way off. I believe it was way too lean..

.840 from the top of the tang (adjuster) to the bottom of the float was the closest. I connected each carb to the fuel line, did a wet check and they seemed good.

Put the carbs back together, and then back on the bike. Closing the mixture screw on carb 3 will make the bike stumble now. Carb 4 still does nothing adjusting the mixture screw so I did another wet check and it is too lean! Can't believe it.. Also, I checked carb 2 and it is a a few mm's too rich. I guess the only way to do a real wet check is to have the carbs on the bike. Is it common to have to remove the carbs 10 times to get this right? It is becoming not worth my time to screw with this anymore.. I imagine paying someone to set the floats shouldn't cost me too much..

Not really, almost sounds like something is binding a little. Do the floats bounce freely, maybe the posts are slightly bent? After setting by measurement do you bounce the float up a couple times and recheck the measurement before buttoning it back up?

 

[infinity999]

Float seems to move freely. Pin doesn't look bent..

I would adjust the tab on the float, close it up.. Fill it with gas and do a wet check on the bench.. Not sure why the are measuring out so much differently on the bike. I didn't tap them this time, maybe something is sticking.. I'll go check that..

 

[dannymax]

I rotate them upside down and back slowly to make sure the float & needle are working nice and smoothly.

If your bench top wet level test is good they should be good on the bike.

-Make sure the carbs are level for the wet level test
-Add pressure to the fuel going in the float chamber to approximate the fuel pump pressure

 

[NHVmaxpower]

That's so weird that we are all getting different results using the casting circle on the jet block why is that?
I Hope I don't have to go through what infinity is going through. Although I bench wet set n checked them 3 times till they were all the same.

 

[infinity999]

The way I added fuel to the carbs was connecting them to the bike, pull the line off, go the the bench and check. Maybe I need a constant supply of fuel?

 

[NHVmaxpower]

You can do it on a bench I used a bottle filled w gas so the bowls never emptied. I ad my wife hold the bottle up w the gas while I checked them. I found that you get different readings unless the bowls are constantly full.

 

[infinity999]

Good idea, but I think I'll just get 6 feet of hose and run it from the bike to the carbs on the bench . They will be constantly full for sure.

 

[NHVmaxpower]

Good idea, but I think I'll just get 6 feet of hose and run it from the bike to the carbs on the bench . They will be constantly full for sure.

Good idea but my bikes in my living room (would need 60ft of fuel line)I did my carbs in the cellar.

 

[infinity999]

I have definitely learned my lesson.. Next time I will not mix up the floats and hopefully they won't need any adjustment..