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Valve clearance
03 Sep 2024 21:35 #257421
by facade
If it suddenly breaks, go back to the last thing that you did before it broke and start looking there
Replied by facade on topic Valve clearance
Which Jimny?
A gen 4 is every 40,000 miles.
The problem is that the clearances tend to close up, then the valves don't seat properly and you get compression loss and seat damage.
The gen 3 can be adjusted fairly easily, the G series Have proper adjusters, and the M series have shims on top of the buckets, that can be changed in situ.
The Gen 4 needs the cams removing to adjust the clearances, I believe that the whole bucket has to be changed, there isn't a shim underneath it.
The official service price includes valve check/adjustment, (which is why some of them are so expensive), money for old rope if they are within spec, probably loses money if they need adjusting.
The best idea for a Gen 4 is to get a gasket, and check them yourself just before you book the service. Then if any are out, stick the cover back with the old gasket and book the full service, if they are fine use the new gasket and only book a short service.
A gen 4 is every 40,000 miles.
The problem is that the clearances tend to close up, then the valves don't seat properly and you get compression loss and seat damage.
The gen 3 can be adjusted fairly easily, the G series Have proper adjusters, and the M series have shims on top of the buckets, that can be changed in situ.
The Gen 4 needs the cams removing to adjust the clearances, I believe that the whole bucket has to be changed, there isn't a shim underneath it.
The official service price includes valve check/adjustment, (which is why some of them are so expensive), money for old rope if they are within spec, probably loses money if they need adjusting.
The best idea for a Gen 4 is to get a gasket, and check them yourself just before you book the service. Then if any are out, stick the cover back with the old gasket and book the full service, if they are fine use the new gasket and only book a short service.
If it suddenly breaks, go back to the last thing that you did before it broke and start looking there
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04 Sep 2024 09:37 #257427
by facade
If it suddenly breaks, go back to the last thing that you did before it broke and start looking there
Replied by facade on topic Valve clearance
It won't hurt to check them after 15 years.
Make sure you buy new circular rubber seals for around the spark plug holes, these dry out with the heat and leak oil, filling up the spark plug hole and causing a missfire.
(I guess it is carbon in the oil, as oil is a good insulator)
If they need adjusting yours is shims on top of the buckets, there are expensive special tools, but you can contrive something to push the bucket down by the rim while you flick the shim out. If they are too tight, you can polish a bit off the valve side of the shim and not have to buy any.
Make sure you buy new circular rubber seals for around the spark plug holes, these dry out with the heat and leak oil, filling up the spark plug hole and causing a missfire.
(I guess it is carbon in the oil, as oil is a good insulator)
If they need adjusting yours is shims on top of the buckets, there are expensive special tools, but you can contrive something to push the bucket down by the rim while you flick the shim out. If they are too tight, you can polish a bit off the valve side of the shim and not have to buy any.
If it suddenly breaks, go back to the last thing that you did before it broke and start looking there
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