Street fighter/ Bobber build 2.0

[motoman]

With floats installed, would check that each one is parallel with carb boby as there is minimal clearance room. This causes many a float to hang up a bit dragging on float bowl.

[Schming]

Valve Adjustment ?

Fearthepack, have you checked the valve shim to cam lobe clearances ?

IMHO this should be the first step in the tuning process, 'cause it affects how well the carbs will work.

I just reread the whole thread and maybe I missed it but no mention of a valve adjustment.

BTW your bike is a looker and hats off to ya for your attention to detail, really nice.

JAT, the forced air by mouth into the bowls may be too much pressure that may be displacing the fuel, also the 2hr. interval may have let the fuel evaporate a little letting the floats drop some.

[Fearthepack]

yep valves in spec...
Ok after letting the carbs full of fuel on the bike overnight i removed and dropped the bowls as fast as i could and 2 of the floats had minute amount of fuel in them after shaking them. For observation I followed DiverRay recommendation marked the 2 bad ones and put all in a pot on the stove. One known bad one bubbled fairly well the others did nothing even the other known bad one never bubbled....at this point i can't trust any of them. I have some extras hiding somewhere i will try, then may order plastic ones.

[Schming]

Seems like you found the culprit.

Checking the threads, looks like the XV920 float seats and viton tipped needles with the plastic floats are the way to go in the early carbs.

[DiverRay]

If you marked the spot that the bubble came from, you can fix that float! Just use a solder iron and a bit of solder to seal it. DO NOT try to use a torch!! You will have the float in bits if you try. DAMHIKIJK....

[donebysunday]

yep valves in spec...
Ok after letting the carbs full of fuel on the bike overnight i removed and dropped the bowls as fast as i could and 2 of the floats had minute amount of fuel in them after shaking them. For observation I followed DiverRay recommendation marked the 2 bad ones and put all in a pot on the stove. One known bad one bubbled fairly well the others did nothing even the other known bad one never bubbled....at this point i can't trust any of them. I have some extras hiding somewhere i will try, then may order plastic ones.

Will the plastic floats work in carbs designed for the brass ?

If you decide to get the plastic floats there is a really low price on some good plastic floats, eBay auction # 113336776088 # 113336776067 # 113336776086 and # 113336776049

[Schming]

Will the plastic floats work in carbs designed for the brass ?

If you decide to get the plastic floats there is a really low price on some good plastic floats, eBay auction # 113336776088 # 113336776067 # 113336776086 and # 113336776049

Lots of threads that answer your question here:

http://www.xs11.com/forum/search.php?searchid=2858700

Bottom line is that, yes they will work and seems like folks have the best results with matched sets of needle/seats, viton tipped or brass, but there is a small clearance issue mentioned between the plastic float and the early carb innards, in this thread:

http://www.xs11.com/forum/showthread...ts+early+carbs

[donebysunday]

Very interesting, thanks for that. Think I tried this years ago on a XS650 and did not work out. Now I'm thinking I just did not have the technical knowledge at the time.

[Fearthepack]

OK, the extra floats I have are the 1980 plastic ones. Read through your posts on adjustments needed for the plastic floats did what I thought was needed to use them. Set height at 26mm and getting a good seat. Tried blowing into the gas inlet and couldn't get the seats to fail.....this is good.

Start caranking and gas shooting out the enricher (10 oclock hole on bell) on 1 and 4 carbs...BTW I have never had flooding out the back of carb this whole time except only when cranking.

Reset height to 27.5mm just to omit fuel height as a problem. Shoot the bowl should be only have full by now.

Same results except 2,3 carbs decided to randomly jump into the action.

Side note plugs are bone dry I would expect them to be wet. Going to see if anything crawled into the carb boots.

Just seems like the carbs are not delivering fuel into the motor but instead throwing it out the back. This bike maybe possessed.

Not sure how I go from last jet change and a great running bike to no mans zone....

[skids]

I don't know, but you might need to explore the need for a different float valve needle to work with those plastic floats.

[bikerphil]

Are you 100% sure the fuel supply lines are going to the LOWER carb T's and not the upper venting T's? What about the fiber washers for the seats, are they torn and not sealing? When you initially fill the carbs after installing, are you tapping the float bowls with a screwdriver handle to prevent the floats from sticking on the bottom and causing flooding?

[xs11lover]

Are you 100% sure the fuel supply lines are going to the LOWER carb T's and not the upper venting T's?

Ha! I’ve done that......twice!

[Fearthepack]

Fuel to lower carb T is correct..
Tapping float BOWLS while filling yes every time...


Houston we have a problem!!!!

This sentence got me thinking...."Just seems like the carbs are not delivering fuel into the motor but instead throwing it out the back."
If spark plugs are dry why is the fuel not making into the cylinder?
Lets check for compression pulled #1 plug put finger over the hole cranked it over nothing, nothing WTF checked 2,3,4 and nothing. I have no compression at all. Could explain the fuel getting blown out the carb no suction to draw it into the cylinder. IMO
Lets All shed a tear about now.

I removed the carb boots and exhaust looking for foreign stuff (rags, paper towels ect but nothing. Removed the valve cover, timing chain still on and turning as well as cams rotating and lifters moving BUT when turning by hand the motor gets hung and won't rotate, a slight bump with the starter and can rotate more.

At this point the damage is done.
What i believe has happened is the timing chain has skipped a few teeth and now the timing is off. When turning the motor by hand at some point I believe the piston is bumping into the open valves and it takes the starter to compress the springs to rotate further. I'm sure some bent valves are going to be present.

Trying to figure if timing is off... so when I line up the cam dots to the cam arrow caps the timing wheel is pointing to 60* while #1 piston is all the way to the top of it's stroke. Other way is #1 piston is all the up and timing wheel pointing to the"T" symbol the Dots are past the cam arrows and the dots are at 2 o'clock....I'm getting a little punchy but shouldn't the "T" on the timing wheel be pointed to while the dots are lined up with cam arrows.

[bikerphil]

Yes, the crank pointer should be at 'T' when the cam dots line up with the arrows on the caps.

[DiverRay]

If you still have the "factory" cam adjustment on the engine, that is probably what bit you! Make sure you get a ratchet type adjuster for the cam when you put things back together! The 6mm bolt just does not hold the plunger when you do a quick de-acceleration. This has caused a few engines to need valves.