raw fuel from #6 exhaust

[vincenzo]

97 Valkyrie has raw fuel coming out of #6 exhaust.  Carbs just overhauled, but was doing this before overhaul.  Still leaking but only when running or cranking.  Does NOT leak when not running or cranking even when petcock vacuum is applied with manual suction.  Compression on #6 consistent (150 psi) with all others (except that 1,3, and 5 are 90,110,90 and 2,4,6 are 140, 150 250).  When running, engine seems smooth.  Good spark on all 6.

What else might be the cause?

Stumped in Massachusetts.

[da prez]

  You have a couple different issues. Leaking carb is possibly a bad or incorrect float needle seating issue.
 The float setting could be to high. 
  The low compression is separate from the fuel.  May need to check the valve settings. If you do one , do them all.  If unsure of doing the work , call out for help.

                                da prez

[vincenzo]

Thanks for the reply.  I forgot to mention that #6 is not firing either, despite having good compression and spark.  Swapping/replacing plugs made no difference.  I wasn't aware that there is an adjustment for float height since these don't have an adjustment tang.  The float valve has been replaced, but since the seat is pressed in, that's original.  All of the plastic floats were checked to make sure they don't leak too.  I'll have to investigate the float situation next.  So to recap, I believe that the fuel leak coming from the exhaust is due to the cylinder not firing. The raw fuel is just getting pushed out the exhaust port

Thanks again.

[vincenzo]

Problem solved.  I just fired my carb rebuilder(me).  Pulled the float bowl off to find the slow jet sitting in the bottom of the bowl. Put it back and all is right once again!

Finally, though, why does one bank have so much lower compression than the other?  Problem for another day.

Thanks for being there.

[WintrSol]

Finally, though, why does one bank have so much lower compression than the other?  Problem for another day.

Thanks for being there.

What do the spark plugs look like, especially left vs. right side?
Any smoke on the left side for a short while after starting?
When was the last time the valve tappet clearances were checked?

[vincenzo]

All the plugs looked the same (except for #6 , of course).  Will check the smoke once all the excess fuel has burned off and I start from cold.  Tappets not adjusted for a long time, so will wait on that .  Suppose the timing gear on the right side had slipped a tooth.  Would that account for different compression between the banks, and if so, I would think the bike would not run as smoothly as it does.  Anyway, another day, and thanks again for your help. 

[luftkoph]

Check your valve lash, see if that improves your compression readings

[Jims99]

Now that the fuel is burning out of the cylinders, recheck your compression. May be closer not having raw fuel in there.

[Mooskee]

Now that the fuel is burning out of the cylinders, recheck your compression. May be closer not having raw fuel in there.

Also check your oil and make sure gas didn't get past the rings into the oil. For the price of an oil and filter change versus having gas changing the properties of your oil, you probably need to just change the oil and filter.. Glad you figured it out and it was an easy fix.

[da prez]

If you jumped a tooth (cog) on timing belt , or even had the slightest thought , I would check the belts. A destroyed engine is next if belts are bad.  Rock Auto has the gates cross belts .

                                                 da prez

                                         

                                                 

[rug_burn]

       THat's kind of a weird one, the low speed jet must have been on only hand tight.
       Every once in a while I miss something like that, too.   
       The problem is even though you fired your mechanic (you) he's still stuck with the job 'cause like all old stuff, it's hard to find anyone to work on it...