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BEWARE--Must read for ALL Boss Hoss Owners!!

5464 Views 12 Replies 8 Participants Last post by  HogV8
Hey Guys and Gals this is my first post but it is big one--#7 cylinder filled with gas and caused my 502 to bend a rod while starting! The bike sat for 12 days and I did not turn the gas off :evil: :evil: :evil: so it is costing me dearly! Thought it would be a better idea after we started adding up the cost of upgrading the "plane ole whimpy 502 :wink: " to go ahead and get a big boy built!

The lesson here is DO NOT FORGET TO TURN OFF THE GAS AT THE TANK!! Faliure to do so will set you back a bunch of money! I have pictures of the damage but I do not know how to post them here.

Take Care!
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Flooding the Engine


Were you running the #1910 Edelbrock Q-Jet carburetor?

If so and if you had the recommended gas filter installed in the carburetor inlet, it has a spring loaded safety valve that takes fuel pump pressure to open. Gravity alone won't open the valve.

Did you have this filter in the carb?

Thanks for letting us all know.
Yup , have heard happen to a couple of people both big and small block also other makes and models of bikes.
Riding for 35 years I always was in the habit of shutting the fuel off when stopped, even just to run into a 7/11 for a cup of coffeee. I've heard of bikes dripping fuel and people coming out seeing they're bikes on fire also. A good habit to get into regardless. Some people get used to a vaccuum controlled petcock and forget shutting the fuel down.

My information is that it was removed per the Boss Hoss Tech Bulletin, which states to remove it. If you do not it restricts fuel flow at high RPM but I do not remember if this was done. I would go look at it but I sent the Carb, Intake, Distributor, Flex Plate, Harmonic Balancer (to remove the inside weight as the new Shafiroff engine is internally balanced) and new Mountain BH Headers to Bohemia NY for the dyno runs and tuning. The transmission is at Nesco having the HD Torque Converter along with new clutches and planetary installed.

Should be a bad boy as Scott is known for his engines—should dyno about 700-725 but with the carb mods may make it closer to the 750. The engine will have a very flat TQ curve—Scott sent me a fax of an engine built last week that was a 540 like mine that made 623 ft of TQ at 3000 and was still 598 at 5900! Anyone have suggestions on the tire—the Avons suck with the small contact patch and I am leaning toward the “I” type MT’s. My bike is an 02 with the good 03 brakes (they are sweet I can haul it down with 1 finger!) retrofitted and stock wheels.
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Hi Guys.....It's not always the filter!!...At the BH Rally at Tan-Tar-A,when I tried to crank mine I noticed alot of gas coming out of the exhaust pipes (About a Gallon!!)..I didn't know what the Hell was going on,But at least I didn't try to turn it over anymore.
With the Help of Carb Mike,Geezer,Mark from the factory and a couple other people we took the plugs out and turned it over and it squirted gas about 15 feet....
They took the top of the carb off and cleaned inside and when we tried to crank it it did the same thing....Gas everywhere!!!.
They checked the Holley red fuel pump I was running and the internal fuel pressure switch had gone bad was pumping to much fuel.
I put the stock pump back on (I carry as a spare) and it ran perfect.
I now use the Carter electric pump and everything is fine..

Badger...Dave :? :lol: :(
Man that sucks . Seems like there is always someting new to worry about. I thought the days of turning off the petcock ended when I bought the Boss.
Re: Flooding the Engine

hossbuilder said:
Gas filter installed in the carburetor inlet/ safety valve that takes fuel pump pressure to open. Gravity alone won't open the valve.

That also means all owners with the small filter/valve in the carb
can leave their emergency long fuel hose for gravity feeding the carb
at home because it will not work on their bikes.

I'm glad to have a proper ventilated main tank now. I can remember
the pressure in my 99' tank in summer when I had no gas tank
ventilation "Weber-style" :)
Without this ventilation it was enough pressure to flood two engines at one time.

Now that I know what can happen (thanks Dave) I'll prefer to turn the
petcock off in the future when I park the bike- just for safety reason's.
Even if I already know I' ll forget to open it every second time I depart somewhere :oops:

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I took the vacuum operated shut off petcock off my Harley , threw it away and replaced it with a Pingel manual petcock. Now the vacuum petcock doesn't sound like a bad idea for any bike as long as it flows enough gas. Turning the petcock off every time you stop can be a pain in the ass especially when you got CRS like me .

<<Turning the petcock off every time you stop can be a pain in the ass especially when you got CRS like me .>>

That is the truth. I'm the same way and everytime I've set my alarm on the bike, I've forgotten to disarm the thing. CRS at work as you say! I guess I will tape the old acronym "FINE" (Fuel, Ignition, Neutral, Engine Cutoff) on my tank or something to remember the petcock.:) Just got to get in the habit or make a checklist!

I always thought that I was immune to this problem because my bike uses a mechanical fuel pump. When I tried to leave the Steel Pony's rally today I thought my starter was locking, so I rocked the bike back and forth with the clutch engage trying to dislodge the starter, but no luck.
After trying this a few times the motor finally started turning over and gasoline started coming out of both exhaust.
Luckily it didn't start the first time or I may have bent a rod also.


Which carburetor are you running? If Edelbrock, have you removed the paper filter on the input line in the housing of the carburetor that has the integral valve to prevent flooding?
For what it's worth I found that my small carb. inlet filter did not have the rubber valve in it . Must have been removed by either the factory or the dealer I bought the bike from new because I have never replaced this filter. Supriseingly the filter was very clean . I replaced it with the proper filter with the valve in it . I guess I'm just lucky that I never had a problem because I never have shut my petcock off unless I was working on it .

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