Rude (1981)35 hp twin carb with Picture

[Lubosleftboot]

I have sorted out all the wiring and ignition issues with my engine so I have now turned my attention to the fuel system.I have found new o-rings and seals fitted by previous owner perhaps but the carb was badly varnished.I have also noticed that the main jet appears to be bent so that it touches the inner ring of the outer jet as in this photo<br /><br />

<br /><br />Is this normal or has the jet been damaged somehow?Would this effect engine running?Can I replace just the jet assembly or do I need a new carb.

 

[OBJ]

Re: Rude (1981)35 hp twin carb with Picture

That's normal Lubos...it's the idle pick up tube.<br /><br />Make sure you soak the carb out in carb cleaner to get the varnish out. Follow up with compressed air.

 

[Lubosleftboot]

Re: Rude (1981)35 hp twin carb with Picture

Thanks OBJ just making sure mate

 

[Lubosleftboot]

Re: Rude (1981)35 hp twin carb with Picture

I have got the engine up and running today and she is pumping water charging and running ace as long as the choke is on??<br /><br />The plugs have a light tinge of black on but are not fouled as in a flooded engine.My question therefore is what can be causing this?The engine runs fine when the choke is on, idles perfectly and runs through the rev range no problem.I have fitted a new carb kit and perhaps the float height is wrong?<br /><br />Could this be caused by a blockage in the carb even although I followed OBJs advice and cleaned it properly with carb cleaner and fitted a new carb kit?<br /><br />Could it be the main needle setting I have this at 1 3/4 turns out is this wrong??<br /><br />All advice is gratefully received guys

 

[Lubosleftboot]

Re: Rude (1981)35 hp twin carb with Picture

Hallo guys any ideas as to what is wrong here??

 

[dwest]

Re: Rude (1981)35 hp twin carb with Picture

I had the exact same problem with my 1977 35 hp after a cleaning and rebuild. I ended up taking the carburetor off again and drilled out the welch plugs (the little aluminum things) and made sure everything was clean. I also replaced the fuel supply lines in the engine compartment. I think a small peice of the old line dislodged when I hooked things back up (just a hypothesis).<br /><br />It has run great ever since.<br /><br />The masters of this site warn of running with the choke pulled. It is a sign of running the engine too lean, which is not a good thing.<br /><br />Hope this helps.

 

[Lubosleftboot]

Re: Rude (1981)35 hp twin carb with Picture

Hi Clear Horizons<br /><br />Thanks for replying but I have done most of the thinks you have suggested.There is a new carb kit, fuel filter and fuel lines fitted to this motor.I know that if the choke is on that the motor is running lean I just need to determine why it is running lean...

 

[rodbolt]

Re: Rude (1981)35 hp twin carb with Picture

if it runs with the choke on you still have trash in the carb, you really really need to learn what and how the carb circuits do. it has no main adjustments and all the fuel the engine burns comes through the main jet,located in the fuel bowl, before entering the idle circuits.<br /> when you remove the 7/16ths headed bowl drain screw the main jet is behind it and takes a special removal tool. most screwdrivers simply chew off the jet slot.<br />looking at that carb pic it was severly varnished.<br /> will usually require a lot of soaking and running strands of copper wire through the passages.<br />by applying the choke your forcing fuel to bypass all idle and main circuits.

 

[Lubosleftboot]

Re: Rude (1981)35 hp twin carb with Picture

I stripped the carb again and cleaned out all the air ways with carb cleaner and compressed air but these were not my problem.When I stripped the carb I put the carb bowl on a piece of glass and it was slightly warped.I changed the bowl for another I had in my shed and the engine runs fine now with the choke off.<br /><br />Link:-http://media.putfile.com/rude-boy-80

 

[Lubosleftboot]

Re: Rude (1981)35 hp twin carb with Picture

The motor must have been drawing air between the carb bowl and the carb body yet there was no apparent fuel leakage there..