400 diesel

[Anonymous-0]

Howdee all.
Just one question.
is there any way to increase the idle rpm on the gas side of this diesel?

I havent checked the rpm, but this one seems to be a bit low. and i dont know what the idle rpm should be.

thanks in advance
J in Pa

 

[Janicholson]

Generally the fact that is is running is enough. There is no real "idle, as the engine is not activly throttled. The size of the carb determines the start running speed. If the speed is low, there may be a "tuneup" issue in terms of plug condition, wire condition, cap/rotor, spark advance, or point gap. There is no centrifugal advance, so timing of a mag impulse trip is at TDC, as is the static timing of the points and coil system (whichever).
There is no throttle plate, there is an air valve, but I do not think it is adjustable.
I would go to the tuneup issue and timing first.
Mi 48 MD ran at about 850 on gas. Jim

 

[TedinNE]

As Janicholson said, tune it up & check all the adjustments first. You can speed up the RPM on the gas side. Remove the carburator, not a fun project. Take the disc off that you see on top of the carb. Put a small washer under the disc. This will raise the engine speed on gas. Will not take very much thickness.

 

[M Diesel]

They can be shimmed to adjust but it isn't usually necessary and as we know that carb is a pain to remove. Tweaking the advance is more useful for the most part.

 

[cushman]

On a 400, there is cetrifugal advance,but there is not very many degrees.My 400 runs about 1100 rpm on gas in warmer tempuratures.Like others said do a tuneup,including ignition timing.

 

[Wardner]

For what it is worth, the 650D carbs have a knob in the operator's position that can be turned to increase the speed. It's possible that a 450D carb is similar.