Carb Issue

I'm having a issue with the Hatichi's on my new XJ 650H. I replaced the needles in the float valves because the oil level would rise in the engine and it smelled of fuel. I set the float levels at the recommended 17.5 mm and checked them using the clear tube method. The levels are dead nuts to the spec. After checking all of the float levels I let the carbs sit in the test rack. After about 3 to 5 minutes # 3 starts overflowing. I've changed the float itself with a spare, checked the float valve gasket, and looked at everything I could think of. Anyone have any ideas? I've ordered a new valve assembly but can't see anything wrong with this one. What could cause the valve to seat that start to leak other than a float filling and sinking? Could a bad enricher seal cause this issue?

 

Take an unpainted golf tee. Cut the head off and chuck that into a drill. Take the drill and stick the end of the golf tee in your seats. Give it a nice drill just enough to polish the brass in there . That should dress the seat a little bit and get your new pins a chance to seat.

 

Float needle is not seating properly, when that bowl stars to overfill, tap the bowl with the handle of a screwdriver, it should stop the flow.

 

i don't golf so i use 0000 steel wool on a q-tip with my fingers, just enough to make it a little shinny

 

anyone think its the choke?
or did i just say something really stupid because this is a fi bike

 

Sticky float or valve not seating. Does your petcock need addressing too, does it shut off OK when the bike isn't running?

 

The petcock seems to be fine. The tank sat for 3 days with fuel in it and the petcock on main with no leaks. I took it for a 20 mile ride today after changing the oil. I put 3 quarts in the crankcase. That put the oil level right in the middle of the window with the bike on the center stand. Just went out and checked it. I can just see the air bubble in the top of the window so its still leaking. I'm thinking its only putting a couple of oz of fuel into the cylinder which is draining into the crankcase. But that's enough to thin out the oil after a couple of runs. So the consensus is that the new needle is not sealing in the old seat? OK I'll remove the carb rack and wait for the new needle set to arrive.

 

turtlemann14
these guys will spank ya if you call it a choke
it's a enrichment circuit
it opens up a air passage that lets the carb suck more fuel than normal
it doesn't do anything till air starts going through the carb
i still call it a choke too

 

No you get choked for calling it a choke :lol:

Back to the issue - It should be impossible for the valve to leak unless it has a fuel supply (that is your petcock leaking or set on Prime). It could be leaking some when you are running. Others have indicated this can happen but I don't see how.

Do you have a clear inline fuel filter? Dos it empty if you let the bike sit a bit?

 

Bill no inline filter. Inside of the tank is pristene. This bike had been very well kept by the PO. I had to look for rust to polish when I got it. OK if the enricher curcuit is only functional when there is airflow that should rule that out. While I'm waiting for the new valve set I removed the old seats and polished the ID's with simechrome. Replaced all of the seat gaskets and reset the float levels to 17.5 mm dry. The blow thru test while the rack is upside down showed that #3 was still leaking. At this point I'm just going to wait and replace the seat assy.

 

Personal experience: I rebuilt the carbs on my wife's bike right after I got it as the carbs came from a bike recycler. I picked up four kits from the same recycler (he sold new parts, too). I wasn't impressed with the kits, but went ahead and used them anyway. That was a decision I soon regretted. On the way home from work a few days later, I experienced the dreaded swamping of the engine. Fuel was literally pouring out onto the ground; the crankcase was so full. I'm amazed I didn't blow up in a huge ball of fire!

I immediately ordered kits from Chacal and haven't had a problem since!

 

all good info, I learn a lot from you guys. Is there a stick on 'how to set float level'? Thanks

 

You can have a crack in the carb body letting fuel in too.

Remove the float and needle and seal the float seat with your finger. Blow and make sure there is no leakage.

 

I found a float level chat, sorry and thanks...

 

Removed the seat and did the blow test. If that carb body has a crack I can't detect it. Thanks for the idea, I han't considered that

 

That's very good news.

 

I'm still waiting on the new float so that has given me time to think. I know that's a dangerous thing in my case. I pulled the plugs just to check. This is after a 40 mile around the town ride at about 50 degrees outside air temp. # 4 was scary white! So, crabs are leaking when static and running lean during operation. Is there a test that the collective knows of for throttle shaft seals? They are a PITA to replace but it might fix the lean problem. I also pulled the intake boots. All had gaskets but where just over finger tight for torque. Do you guys use gasket sealer on those surfaces? When I had the sync sticks on this engine there seemed to be plenty of vacuum as the mercury was half way up the columns. This bike only has 13K miles on it and other than some hanger rash is in excellent condition. Maybe that's distracting me from what I would normally do to a new to me machine which is replace everything with new if I can find it. See I told you thinking was dangerous.

 

Quick simple vacuum leak test is. Get a propane tourch. Start the bike up and turn the propane on and place the (unlit) tourch around the carbs and see if the idle picks up. If it does you can narrow the leak down. Hope that helps

 

Well I think I figured out the plug color and solved the rising oil level issues. Closer inspection of the plugs revealed that they were 2 heat ranges hotter that stock! In addition I pulled the boots and resealed the boots to the head. The gaskets were intact but there was no sealer. Installed the correct heat range of NGKs. While I was waiting for parts I checked the valve clearances which were well within spec. Thanks to chacal for the fast delivery of the 4 deluxe lower carb kits. Installed those and set the levels to .750. The 11/16 settings resulted in high fuel levels in all of the bowls. Let the rack sit in the test fixture with head pressure on it for about an hour. No leaks, no overflow. Remounted the rack and the test ride around the block showed everything running well. It was in the upper 50s for a while here today so a 40 mile test ride resulted. This thing is running sweet. Thanks to all for the help.

Dave