[Dan4809]

We have a 840 Honda that we are still running carbs on. It has always ran great on our carbs until this past saturday at Shelbyville. The problem is it responds good when u first nail the throttle, but about half way down the straight aways it would quit pulling and sounds like it's sputtering. It has always had fuel in the bowls. Could it be flooding to much fuel, I'm leaning towards running out of fuel. I'm going to test the fuel pump tommorrow, should it pump a gallon of fuel in one minute. I also checked the engine for ground issues and it was good, it was 0.1 ohms resistance to the battery ground. Any suggestions would be appreciated.

[badcoupe]

def running out of fuel under load what pump are you using? Also the battery can show good voltage but when under a load the voltage can drop off and cause ign and fuel pump issues, Id lean towards a pump issue though.

[Dan4809]

It's a red pump. Is a good rule of thumb that if it will pump a gallon in one minute, it should be good. The battery was showing 13.2 volts in the pits, I would think it would not fall that far under race conditions. I checked my floats again, set at 26mm or 1 1/32 inch. We were running 105 main jet, thought about trying 115, what do you think. Thanks Dan.

[TQ29m]

.105 main jets are larger then the dump tubes, so you are already over on jet size. .086 is a good combo, with a red Holley, and a bypass, not a regulator, set at 3/4 gal per minute, floats at 3/16 from the top of the bowl. 13.2 v at no load isn't a test, it's a sample, hook your VOM between the battery ground, and the pump grd, and see what you have, anything below 9.5v and everything starts to retire, especially with a Dyna. The 3/16 number is done by setting the floats, till you get that much fuel in the bowls, by running the pump, and removing the bowls, that's real close to running over, but you need it. Bob!

[badcoupe]

Those jets are wayy big. I never had much luck with the holley pumps on a tq.A bypass certainly works better than a regulator on these cars. These carbs are pretty reliable and simple getting the supply system working properly is typically the issue for most people.

[TQ29m]

Only problem I had with the Red Holley, was the danged magnets would come loose, and stop things, so I finally took the can, and cleaned it real good, and siliconed them in place, and stopped that problem. Lot of guys used that little "pecker" pump, Facette, or Fawcette, it ran at max all the time, but it worked for some, but even it would dunk the floats at low speeds, I know Ambrose will not agree, but if you can find a set of the brass floats, put them in, those later foam jobs don't really like alcohol, and over time, will get "heavy"! And, by the way, if you haven't converted your jet holders to be able to use Holley jets, I can do that for you, makes it easier to find a range. Bob

[Dan4809]

I guess I don't know what size the jets are then, they are printed on the bottom of the jet. I have a set that have .120, .115, and .105. That is the only way I can ID them. I don't have a regulator, I have the return on it. Believe it or not, we use a hose clamp on the line and that is how the pressure is set. We have not had any issues until now. I did find an issue today that two of the four air screws were completely closed, we always set them at 1 and 1/2 out. Dan

[TQ29m]

The hose clamp is nothing new, it's been used for years. The numbers on the jets, are they stamped or etched? Best thing to do is get hold of a number drill set, and use the drills to compare the hole size, they could be re-drilled, and be way off! Bob

[Dan4809]

They are stamped. The odd thing is the car ran great until last saturday with this setup. The jets have never been changed. I don't know if you received my PM but I did notice that the 2 outside air screws were tightened all the way down and the 2 inside carbs were a 1 1/2 turns out. I have always ran them 1 1/2 turns out. I do know with a little research today that they are honda jets, not holley and they only offer a 105 110 115 and 120. Thanks again for all your help.

[TQ29m]

Those numbers refer to a part number, not a size, ck them with a number drill set, I'm bettin they've been drilled out, you need to get a handle on it, ck them, so you'll know for sure, and, if you have a Dyna, you could have a module going, or gone bad. Go to cb750supply.com, and you'll see what I mean, they are just a reference number. They also have a very nice ignition system available there, and a lot cheaper than a Dyna! Bob