Z482 fuel pump adjustment?

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Mouse
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Z482 fuel pump adjustment?

Post by Mouse »

After test riding the new build bike I am noticing the engine is overloaded ie smoking when accelerating. There really is a comedy level of smoke and cars back right off. Today the sun was bright and I could see the smoke silhouetted in the shadow :oops:

I notice that if I ease off and increase throttle as I speed up and keep it just off smoking there is a fraction more power then when it smoking at full throttle, the engine tone also changes a bit so I can do this without looking over my shoulder but this is far from ideal. It also smokes when revving up the engine in neutral.
I've had a look all over the pump / governor and have only identified two adjustment screws. One for minimum running rpm the other for maximum running rpm. (both capped and sealed, but now tinkered with). Both these are internal adjustments and separate from the two screws that limit the throttle arm.

I've done a quick search and cant find any reference to making this adjustment to the engine other than the odd idiot exploding into a rant about how the engine will explode in your face if you so much as think about adjusting the governor / pump. There is also no mention in the engine manual of adjusting the fuel pump other than setting the injection timing angle.

Anybody have experience with tweaking diesel pumps. I'd to make it less obviously smoky (reduced max fuel?) and cant help think that this does not help fuel consumption as well as smell bad for the traffic behind.
Kubota Z482 which is plodding on with unnerving reliability. Three years so far.
1900 Diesel Bike being rebuilt with better clutch control.
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coachgeo
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Re: Z482 fuel pump adjustment?

Post by coachgeo »

the folk who tweak IP's on these things the most are almost allway's competitors in some sport. For example the 3cyl diesels are used in small tractors.... well these little things are also competed in tractor pulls just like their big brothers.

What all kinda products is your type engine used in? With that list in hand; do a search and see what wacky group of people modify these things for some obscure sport.
IgorVigor
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Re: Z482 fuel pump adjustment?

Post by IgorVigor »

I've tweaked quite a few diesel injection pumps (usually car/van engines though)

usually the 'max fuel' screw adjusts the injection pump rack fully open position.
but on some small diesels its coupled with the max rpm.....

can you post a pic of the injection pump?


to reduce the smoke without touching the injection pump, you could run some 2 stroke oil in the tank.....a lot reckon a 150~200:1 mix will reduce smoke considerably.....
or run a bit of veg oil (~25% mixture)....I've run diesels on a veg oil mix and always notice a reduced smoke output.....
Mouse
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Re: Z482 fuel pump adjustment?

Post by Mouse »

Someone has pointed out that the air filter is pathetically small so I've going to remove it to see if that has reduced the air flow sufficiently to give equivalent over fuelling and smoke.
Kubota Z482 which is plodding on with unnerving reliability. Three years so far.
1900 Diesel Bike being rebuilt with better clutch control.
arnaud
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Re: Z482 fuel pump adjustment?

Post by arnaud »

can you please tell us more about how it runs??
Mouse
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Re: Z482 fuel pump adjustment?

Post by Mouse »

It runs OK, but at max throttle / demand it smokes a lot. Thick black smoke appears just as it maxes out and also the power reduces just a tiny bit. If I ease off on the throttle it stops smoking and there is a tad more power which could just be smoother running.
I know the whole engine is probably tired as I got it from a rubbish tip and guess rings are probably very worn and not regret not checking them when I had the engine apart.

Its a little bit embarrassing.
Kubota Z482 which is plodding on with unnerving reliability. Three years so far.
1900 Diesel Bike being rebuilt with better clutch control.
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