vfr nc21 only firing on three

[arsey30]

Erm.

I dont' think that much fuel in the oil would be becuase it's standing.

The petrol tap is vaccumn operated so only works when the engine running even if tap is set to on no fuel will flow.

3.2 litres of oil is over half a litre too much.

Check the carbs for leaking!

The fault seems to have occurred after standing for a while
The vacuum side of the tap [diaphragm] may be leaking/faulty or modified for full flow [HRC] and the fact the engine ran with the vacuum hose split does suggest that.
I said both the vacuum diaphragm and 1 fuel valve is leaking.

If the fault came on after the bike had been ridden for a while, then a serious carb fuel needle valve leak is the culprit.
If the 2 tests outlined earlier [tap flow and carb contents] are carried out, all will be revealed.

Dave.

[deno98]

ok update firing 4 still but vacuum pipe working fuel coming out of over flow on tap when vacuum off bike wont run at all so it must be carbs but noticed crack in oil sump leaking oil drip so found replacment for 45 pound but just thinking might just throw a 100 or 150 and get a full engine to replace still blowing even if i get engine will still have saved money on bike any sujestions on were to get an nc24 engine looking on ebay about 100 to 150 thank for your help again

[deno98]

just seen a cheep sump on ebay will an nc30 1989 fit my nc24 1987 thanks again

[arsey30]

If your engine looks and goes OK, stick with the known one, what is the mileage.?
You will still need to sort out the flooding, [unless new engine comes with good carbs]

If it is still flooding in use, then it looks like a carb needle valve is leaking, is the 4th cylinder still firing/running now?

Replacing sump and needle valve is better than replacing the engine.

[deno98]

its got 34000km on clock mot backs up all cylinders are firing but petrol coming out of overflow on tap also was blowing a bit of white smoke but no new oil on down pipes yet oil is leaking tho so need sump will the nc30 oil sump fit a nc24 looks the same also there are carbs on ebay for 32 quid should i just get them or attempt the carb needle

[deno98]

also there is complete nc24 engine with carbs on ebay at 110 now 26000km

[arsey30]

Your choice, but I would not replace an engine because of a possible carb fault.
Do you suspect engine damage from running with contaminated oil [viscosity will have been well down]

How far was it ridden with fuel in the oil. Does it rattle, cams may be the first to show signs of wear.

I might buy a set of carbs, as they come in handy for spares.

[Neosophist]

Your choice, but I would not replace an engine because of a possible carb fault.
Do you suspect engine damage from running with contaminated oil [viscosity will have been well down]

How far was it ridden with fuel in the oil. Does it rattle, cams may be the first to show signs of wear.

I might buy a set of carbs, as they come in handy for spares.

Becuase of the quirkyness of the NC24 you'll have to remove the engine to replace the sump as it means removing the exhaust collectorbox.

Yes the NC30 part will fit, there the same part number.

It sounds like your petrol tap is busted it fuel is leaking from it, inside is a rubber diaphram that operates by vaccum.. the tap does disassemble so it might be worth checking if there is a hole in it.

I'm with arsey30 on not replacing a running engine becuase of a carb probelem..

[deno98]

right sealed crack on oil sump with gasket seal and liquid metal for now
going to get carbs off next and fuel tap but think tap is ok as will not run witout vacuum pipe connected
and when conected fuel pisses out of over flow pipe but will check anyway fuel got in coz vacuum pipe was conected to overflow would this cause that much fuel in oil ?
asrey not sure how much riding was done with fuel in i rode to my house from were i got it say 10 minute ride then work once 5 minute then uncles 5 min he said he hadent rode it because of firing fault but dont know from condition of oil filter last oil chang was way back when so he could of been talkin out his arse

[deno98]

right carbs off were is the carb needle valve