revtothelimit - motorbike forum

I referred to this earlier, but bike engines are a bit of a special case as they a) rev much higher than car engines and b) have a gearbox integral with the engine. I don't think it can be overstated how much extra load is placed on the oil by being squashed between gear teeth, nor how wet clutches add to the contaminants in the oil. And did I mention that bike engines rev much higher than car engines? All of the above make me sceptical about bike manufacturer's quoted oil change intervals.

And in the case of my KTM 690, quoting a change interval of 10,000 kms for an engine with an oil capacity of 1.7 litres is just plain daft. IMHO, obvs.

mangocrazy wrote: Wed Mar 13, 2024 11:25 am I referred to this earlier, but bike engines are a bit of a special case as they a) rev much higher than car engines and b) have a gearbox integral with the engine. I don't think it can be overstated how much extra load is placed on the oil by being squashed between gear teeth, nor how wet clutches add to the contaminants in the oil. And did I mention that bike engines rev much higher than car engines? All of the above make me sceptical about bike manufacturer's quoted oil change intervals.

Thankfully, none of the above apply to mine.

Revving higher isn't as big a deal as some probably think it is. Revs are higher, but piston speeds and bearing linear speeds are pretty similar for example. Bikes rev higher but have shorter strokes and smaller bearings. Diesel engines put higher radial loads on the bearings for example, so you could just as easily make statements that those are worse.

There's a lot which goes into it, nearly all of which you and I would not be privvy to. The OEM is though

You appeared to have missed my point about the gearbox/clutch being integral with the engine on most bikes (not MrLongbeard's though...)

Nah I got it, I just don't think you have enough info to draw any meaningful conclusion. It's not as though the OEMs aren't also aware of the effects the gears have on the oil. They had to design the gearbox too.

No, I don't have the data to draw any meaningful conclusions. In the absence of that I change the oil more frequently...

https://www.ebay.co.uk/itm/401288338782 ... media=COPY

Dodgy69 wrote: Wed Mar 13, 2024 2:47 pm https://www.ebay.co.uk/itm/401288338782 ... media=COPY

The K&N version had a reputation for the nuts pinging off when you tried to undo them.

I reckon I'd be safe leaving the GSXS 7500 miles between changes, else Suzuki wouldn't have said so. But for less than the cost of a fuel fill up in the car or a couple of tanks of petrol on the bike, plus half hour I feel better doing it annually.

Although I do really find it odd that Suzuki say the bike also needs plugs every 7500 or annually. That's a piss take IMO. I suspect cos changing oil isn't expensive enough come service time. The plugs are iridium too, which in my car have a life cycle of 75k miles according to Mazda. Sure a bike probably needs new plugs sooner than that, but not 10X sooner.

Supermofo wrote: Wed Mar 13, 2024 3:05 pm I reckon I'd be safe leaving the GSXS 7500 miles between changes, else Suzuki wouldn't have said so. But for less than the cost of a fuel fill up in the car or a couple of tanks of petrol on the bike, plus half hour I feel better doing it annually.

Although I do really find it odd that Suzuki say the bike also needs plugs every 7500 or annually. That's a piss take IMO. I suspect cos changing oil isn't expensive enough come service time. The plugs are iridium too, which in my car have a life cycle of 75k miles according to Mazda. Sure a bike probably needs new plugs sooner than that, but not 10X sooner.

I've always changed plugs at about 4,000. On track they lost the edge on initial throttle opening.

KungFooBob wrote: Wed Mar 13, 2024 2:50 pm

Dodgy69 wrote: Wed Mar 13, 2024 2:47 pm https://www.ebay.co.uk/itm/401288338782 ... media=COPY

The K&N version had a reputation for the nuts pinging off when you tried to undo them.

That's something that was reported on the GSXS forum. I was going to go OE or Hiflo before reading that. But defo after.

Yorick wrote: Wed Mar 13, 2024 3:18 pm

Supermofo wrote: Wed Mar 13, 2024 3:05 pm I reckon I'd be safe leaving the GSXS 7500 miles between changes, else Suzuki wouldn't have said so. But for less than the cost of a fuel fill up in the car or a couple of tanks of petrol on the bike, plus half hour I feel better doing it annually.

Although I do really find it odd that Suzuki say the bike also needs plugs every 7500 or annually. That's a piss take IMO. I suspect cos changing oil isn't expensive enough come service time. The plugs are iridium too, which in my car have a life cycle of 75k miles according to Mazda. Sure a bike probably needs new plugs sooner than that, but not 10X sooner.

I've always changed plugs at about 4,000. On track they lost the edge on initial throttle opening.

That makes sense. But doubt I'm giving them anything like the pasting they'd get on track.

Supermofo wrote: Wed Mar 13, 2024 3:34 pm

Yorick wrote: Wed Mar 13, 2024 3:18 pm

Supermofo wrote: Wed Mar 13, 2024 3:05 pm I reckon I'd be safe leaving the GSXS 7500 miles between changes, else Suzuki wouldn't have said so. But for less than the cost of a fuel fill up in the car or a couple of tanks of petrol on the bike, plus half hour I feel better doing it annually.

Although I do really find it odd that Suzuki say the bike also needs plugs every 7500 or annually. That's a piss take IMO. I suspect cos changing oil isn't expensive enough come service time. The plugs are iridium too, which in my car have a life cycle of 75k miles according to Mazda. Sure a bike probably needs new plugs sooner than that, but not 10X sooner.

I've always changed plugs at about 4,000. On track they lost the edge on initial throttle opening.

That makes sense. But doubt I'm giving them anything like the pasting they'd get on track.

Also I found they lasted a bit longer if I used Super Unleaded rather than cheapo shite.

Yorick wrote: Wed Mar 13, 2024 3:40 pm Also I found they lasted a bit longer if I used Super Unleaded rather than cheapo shite.

Always use super in my bike. When it went to over £2 odd a litre after the start of the war I did every other tank but now it's just expensive again rather than farking ridiculous I'm back to every tank. Find I get more miles to a tank as well.

I think at next filter time I would put socket to nut but if it's feeling tight I'd have the straps n chains out.

My theory on plugs is, if the bikes running happy, the plugs are happy.

Dodgy69 wrote: Wed Mar 13, 2024 6:16 pm I'd have the straps n chains out.

Didn't know we were that sort of forum

Dodgy69 wrote: Wed Mar 13, 2024 6:16 pm My theory on plugs is, if the bikes running happy, the plugs are happy.

Reckon I might change mine at 16-18k-ish