<VV> Carb Problem

[Tony Underwood]

At 10:48 hours 05/21/2006, BBRT wrote:
>How about something simple like the outer end of the tight balance 
>tube rubber piece-where maybe your flammable mixture did not get to, 
>when you sprayed it?


My next trick here would be to remove the balance tube and plug both 
spigots on the carb bosses to make sure that both sides of the engine 
are segregated, so as to make sure that each bank is running *solely* 
on its own carb.   It should make troubleshooting easier, without the 
balance tube affecting the results.


>>Smitty says:  I had some input from a couple of people that requirs 
>>answers even if they mean nothing to me.  First of all, I swapped 
>>carbs and the problem stayed on the right side.  So, it is not a 
>>carb problem. I ran the compression check again and I have 122 to 
>>125 on all cyls.  I measured vacuum and at the lowest speed I could 
>>get the engine to run I was reading 10-12 on both sides with the 
>>right side being the lower. Using my little squeeze spritz bottle 
>>that shoots a needle jet of gas I spritzed both sides while holding 
>>the throttle at the minimum speed it would run.  It picks up speed 
>>on both sides equally.


That raises the alarm flags.   Why would the addition of fuel 
spritzed into both banks cause an equal speedup unless there's a 
mixture problem?

I'd block that balance tube off and do the spritz test again to make sure.


>>  So the carb swap says "engine problem".  My question to that is, 
>> if there is air flow and vacuum why isn't a "good carb" giving up 
>> its fuel ?  This is more puzzling in view of the engines response 
>> to spritzing fuel in that side.  THIS AIN'T NO FUN ANY MORE.  Yeah 
>> I know I was hollering.  gg




This isn't making much sense.   The only time I ever saw something 
like this before was with an engine that had a couple of intake ports 
on one head almost blocked completely by deposits...  how they got 
there I don't know but two intake ports right behind each of the two 
intake valves in question were almost completely clogged...  you 
could possibly get a soda straw past the clog in each port.   There 
was even crud caked up on the back of the intake valves.

It would idle OK but any throttleup after that produced a dead miss 
in each of the aforementioned cylinders.    A static compression 
check also showed no problems.

Now:  Considering the engine in this instance, I doubt that a clogged 
port would be even a remote a possibility.

I'd really like to see this engine in front of me, running.   ;)   I 
like a challenge...


tony..