post carb cleaning, trouble

[TurboFarviknugn]

I have not taken any XS carbs apart yet so i do not know what the float valves look like BUT, if they are anything like the ones the 9 year old chinese girls make for VW's heres a trick we have to do all the time to get NEW float valves to shut off properly. Hold the body portion in one hand and the pin valve with a pair of pliars apply SLIGHT inward pressure while rotating in opposite directions. Basically causing the two peices to shape each other, kinda like laping in valves WITHOUT the compound.

NOT SURE this will even work with these float valves but just an idea.

 

[bbillington]

Not for nothing, but if you'd like a fresh set of eyes and another set of hands to wrench, I'd be more than happy to swing by next weekend as I recall you're somewhere in the DMV.

 

[emzdogz]

Do you have vacuum petcocks on this?

no, tank has 2 manual petcocks. It's not coated, but fairly clean, and I also have an inline filter.

I was wondering about the tiny plunger on the end of the float needle, which the "tang" on the floats touches when they float full up. That plunger doesn't seem to do anything besides provide a bit of spring action, that I can tell. Or?

I think I'm going to order new floats.

 

[emzdogz]

Not for nothing, but if you'd like a fresh set of eyes and another set of hands to wrench, I'd be more than happy to swing by next weekend as I recall you're somewhere in the DMV.

actually, I'm in Florida...so, it's a ways. thx for the offer though.

 

[emzdogz]

I have not taken any XS carbs apart yet so i do not know what the float valves look like BUT, if they are anything like the ones the 9 year old chinese girls make for VW's heres a trick we have to do all the time to get NEW float valves to shut off properly. Hold the body portion in one hand and the pin valve with a pair of pliars apply SLIGHT inward pressure while rotating in opposite directions. Basically causing the two peices to shape each other, kinda like laping in valves WITHOUT the compound.

NOT SURE this will even work with these float valves but just an idea.

huh. Interesting. I could try it. I have an extra set of the float valves....
thx

 

[bbillington]

actually, I'm in Florida...so, it's a ways. thx for the offer though.

hahahahahah

I have no idea why I thought you were local. Best of luck regardless.

 

[ReycleBill]

Yesterday I saw on Youtube a video which I think was by someone on here - so whoever that is, thanks for the videos! that's wonderful.

I see from that video, one thing I was not paying attention to in setting float height.

I was taking the measurement with the carbs upside down but with floats just loose - not paying attention to whether the tang was contacting the tiny plunger on float needle. To be honest, I didn't even know that was a "moving part" - the plunger.
So I re-did the adjustment (with my third hand, and wearing 2 pair of reading glasses, lol) so that I'm taking the measurement with floats touched a bit so the tang is just beginning to contact the plunger.

Let' see what that does for me.

Another thing: I re-checked the pilot jet, just to be double-sure it's not plugged. It is the stock 42.5 jet as spec'ed for the BS34's. I also see in the listings of pilot jets that could be used for that carb, that 42.5 is one of the richer ones available - i.e. there are much smaller ones of the same type available.

Question: why would anyone ever need to put a SMALLER size pilot jet? Normally any mods involve opening up exhaust, as well as using supposedly freer flowing air filters (pods or unifilters). So it just makes me wonder under what circumstances you'd want to use a smaller size than stock pilot jet. (I always read that the bikes came jetted really lean from the factory).

Thanks again to whoever took the trouble to make those videos.

Much appreciated!

Jetting also changes with altitude so it might be that bikes operated at different altitudes might need the smaller jets. My bike always runs rich when I go to the mountains. If I were there all the time I'd go smaller. My cousin who lives in the mountains always complains that his bike leans out when he rides down my way.

 

[littlebill31]

It is very important to be careful when bending the tang to adjust float height. It's best to remove the float and hold it by the axle housing with a pair of pliers and gently bend the tang with another pair, or something that will not damage them. If you hold the floats themselves and start prying, I guarantee you will twist them and bend one, causing them to become uneven. This will make them float incorrectly. You should always measure both sides of the floats to make sure. I had one side 4mms off from the other.

And yes, the float needle pin/plunger just acts as a spring, but it needs to move freely.

This is my video on adjusting them. Hope it helps a little.

 

[emzdogz]

yes that's the video I saw! Great job!

Anyway, I have ordered new floats, and just for the heck of it, new pilot jets, just up one size (running unifilters). The pilot circuit is pretty obviously the one that's not working for me, so maybe my old pilot jets are still plugged. They don't look plugged. I've cleaned them over and over and can see light through all the holes and the ends.

But let's see what happens with new floats. I have been measuring both sides, but I suppose maybe they're not straight any longer.

Today I'll look more carefully at the air jet, too. I mean I've blown carb spray through, but maybe there's something still in there. It's not helpful that right now we've got all kinds of pollen flying around. Little pieces of crud all over.

Also, I'm really curious what the compression test will tell me. Got to go over to my Dad's today and pick the tester up. Will be doing that with carbs off.

thanks again, everyone, for helping me muddle through and just lending an ear.
I guess now I'm thinking in terms of working on the valves at least, if they need it. I know there's lots of good valve info on here, too. The valves look kind of greenish blue as I see them through plug holes. Like the statue of Liberty. Not the ends you see through valve covers, but the big end (that you hope doesn't ever hit the piston). Maybe that's from the Seafoam. LOL!!!!!!!! that's funny, right? I didn't "get it" til I re-read. Tried Seafoam in my fuel a few weeks back, and now valves appear "seafoam blue", sort of..... I mean not solid blue color, just like dusty.

ah well, happy Monday.

It is very important to be careful when bending the tang to adjust float height. It's best to remove the float and hold it by the axle housing with a pair of pliers and gently bend the tang with another pair, or something that will not damage them. If you hold the floats themselves and start prying, I guarantee you will twist them and bend one, causing them to become uneven. This will make them float incorrectly. You should always measure both sides of the floats to make sure. I had one side 4mms off from the other.

And yes, the float needle pin/plunger just acts as a spring, but it needs to move freely.

This is my video on adjusting them. Hope it helps a little.

 

[emzdogz]

While I'm waiting on my new floats, I've been reading and reading - now I'm wondering if the rubber lip of the Unifilters I've been using are possibly impeding air flow to the pilot air jet on my right side carb. These Uni's are gray foam fairly long ones that I bought just by "fit" (diameter) from the Unifilter site.

If I hold the filter onto the carb to try and visualize, it doesn't seem like it's actually blocking the air jet like the old kind of pods that you could actually SEE where the lip of filter would cover that hole.

Used to have these bright blueish green Uni "sock" type foam filters on before, which didn't even have a rubber lip at all. The foam just clamped directly to the carb. Those filters got burned in a welding-related small fire. But now that I think about it, the bike ran decently well when I used those filters.

So now I'm thinking of trying to see how it starts and runs with no filters...just to see if that makes the difference.
I was always told not to run an engine without the air filters, but I see people on the forum here referring to spraying stuff in carb throat (which would require filter to be off) and otherwise just running with no filters while trouble shooting.

In general, if run without any filters, will it be leaner, over-all?

Last time I went to start the bike after carb re-install, I cranked it 1 time without filters on, because I'd just forgotten to put them on, and I got a backfire out the carb on that bad side (right side that stays cold). Put the filters back on and it didn't backfire as much, but it didn't run long, either.

So, running for brief periods without filters is ok?

thx

 

[bbillington]

You should be able to see if there's a lip inside the filter itself that would disrupt/block flow to the air jet.

Running without filters for testing purposes is no big deal.

 

[5twins]

The UNIs should be fine and not block anything. Many of us run those same filters with no problems. You still have something amiss in that carb. Is sync at least close? If it's way off, that carb could be effectively shut off at idle.

 

[emzdogz]

Visually, and with popsicle stick test, they are synched. But I guess if one cylinder has lower compression and "sucks" less, that, in effect, that would affect the balance, right?

 

[ReycleBill]

I have a plastic gas can with a fuel line, fuel filter and cheap lawnmower petcock running out of the bottom that I use for testing and tuning. I simply hang the can from the rafters with an old coat hanger.

I found everything I needed to build it at the hardware store and it really makes solving carb problems a lot easier.

 

[emzdogz]

Good news. New plastic floats work great - no gas over-flow, even with a little gas left in (clear) line. Had to bend the tangs quite a bit to attain the 21 mm height.

Just for the heck of it, today I started it up with no choke at all. Fired up right away. I mean yes, it is warm here - high 70's. But I've never known one of these bikes to fire up and run with no choke when engine is cold. So that makes me wonder.

Seemed to run better overall - I believe I was getting more heat from right cyl. after the valve adjustment I did the other day. Pulled that pipe today too, to "see" the exhaust valve on that side. Seems to move ok. I'd put seafoam in it awhile back and then more recently some Marvels Mystery oil. Maybe the rings are freeing up and valve seats getting a little cleaner, but in between it's blowing funky smoke out. I don't know.

While it was running today I messed with balance screw, so now it's probably out of balance, if it wasn't before. Right side still doesn't respond much to mixture screw being turned in or out.

Pissed neighbors and housemate off.

By the end, the right pipe wasn't spewing oily gas out as before. Before it totally greased/oiled up the brake rotor, tire, rim, etc.

Looked at plugs, right side slightly gassy but not like flooded, not oily black though - left side (which I've been thinking of as the good side) had fluffy black deposit.

This was all just sitting on the stand at idle or revving off idle with short bursts of higher revving. Smoke comes out right pipe when revved....but only at first - when the higher RPM is held steady it doesn't continue to emit smoke. Comes back down to idle right away.

My guess is the intake valve on the bad side isn't seating correctly all the time.

But I'm baffled as to why it would start right up from cold with no choke.

Need to either buy or make a carb balancing tool. Can balancing with tubes attached to barbs be done at idle? or is that only intended for non pilot circuit balancing (higher RPM running)?

oh one more thing, a couple of times I sprayed the intake boot area with carb spray and it SLOWED the idle way down. It's not making sense to me.

Still need to buy or borrow a compression tester.

My feeling is that something is working itself out, just by running the engine, with regard to either partially stuck rings and/or non-seating valve. Like it's trying to free up.

But the starting up from cold with no choke has me baffled.

 

[gggGary]

Do the compression test already, the suspense is killing me!

 

[5twins]

You sync the carbs at idle. They are joined and operated in unison by a linkage so sync at idle will also be sync at higher speeds. Not synced at idle will also be not synced at higher speeds.

 

[emzdogz]

thanks, 5twins.
And gggGary, one way or the other I'll end up with a compression tester today.
Carbs still didn't overflow during the night, so that's great news.

 

[emzdogz]

here's how it ran as of yesterday (no air filters/started without any choke at all):

 

[gggGary]

From here it's looking like she needs either rings or valve seals at a minimum.