Results of tonights tinkering ...

[Fallout]

Originally Posted by Thunderace

When you start the engine let it run for a minute or two before driving and when you stop let it run for a minute or so, it Sounds like your turbo is struggling but doing the above will make sure it's not still spinning with no oil in it, probly just full of crap so new oil and airfilter should solve it as long as you stick with letting it run for a bit before driving or turning off

Good advice. I've been doing that a bit. Pretty flippin tedious I can tell you! The problem is probably made worse by lots of short journeys to get the mutt to the woods. I think I might just drive under 2k on short journeys so the turbo can stay asleep.

Originally Posted by Mark_h

May I suggest keeping quiet for a bit as of yet we don't know if your new toy is an oil munching frame shredder too. Could you take El Presidento chucking it all back at you?

Yes.


Besides which it'll be an oil munching frame shredder that cost half as much as his oil munching frame shredder and I'll have a fallback plan.

Originally Posted by Fallout

Good advice. I've been doing that a bit. Pretty flippin tedious I can tell you! The problem is probably made worse by lots of short journeys to get the mutt to the woods. I think I might just drive under 2k on short journeys so the turbo can stay asleep.

If it don't help see about getting a replacement cat from a scrappy, too much crap and soot in the cat can make a turbo lag badly!

Does your engine rev then pick up speed after?

[Fallout]

Yeah, perfectly fine after a few minutes. I'd say it's only the first 3 or 4 times you try to get it over 2k when stone cold it struggles. Last for less than a minute really. After that it's fine. Not really a problem at the moment, just one to keep an eye on me thinks.

Originally Posted by Fallout

Yeah, perfectly fine after a few minutes. I'd say it's only the first 3 or 4 times you try to get it over 2k when stone cold it struggles. Last for less than a minute really. After that it's fine. Not really a problem at the moment, just one to keep an eye on me thinks.

If it starts to do it all the time could be your clutch! Iknow a guy who'll give you a cheap quote!

[Wideboy]

i'll giva ya a pand

[Sid Squid]

Originally Posted by Fallout

Universal compression tester isn't universal. It doesn't fit. What a bunch of scrotum. So no compression testing performed.

They rarely are bike 'universal', unless you get one specifically intended for modern bikes, it's unlikely they'll have the 8 & 10mm connectors most newer bikes need.

Originally Posted by Fallout

All spark plugs were loose! Must not have tightened them properly when I put them in because the threads are all a bit knackered in the block, so go tight then loose then tight then loose as you screw them in. I could undo them all with my fingers! Sorted that out hopefully. Plugs looked fine.

Loose and tight until they bottom out, or just loose and tight forever and ever?

Originally Posted by Fallout

Oil on the air intake valves. Just a little.

Where specifically?

Originally Posted by Fallout

There are 6 separate pipes and connectors that go into my airbox. Feck knows what they do. One of them possibly wasn't connected and was quite oily. Weirdness. Connected now.

Depending on your exact model two of them don't, there's a hose and a connector going to it, but it's only mounted on the airbox, not connected to it.

Was the oily one about 3/4" in diameter?

Originally Posted by Fallout

Bike seemed to start a bit better after fannying about. No throttle required. I wonder if that pipe performs some sort of back pressure function. It goes from the air box, just above the throttle body down somewhere into the engine/gearbox area. Weirdness x2.

If it's the one I asked about above, then no, it doesn't.

Originally Posted by Mark_h

I think the general idea is pressure that either builds up in the crank cases and gearbox or bypasses piston rings gets fed back into the airbox. Quite why that's a good idea I am not too sure.

Two reasons, one of which is very important to an SV due to the way it's constructed.
1) Pistons/rings and cylinder bores never make a perfect seal, there will always be some blow-by that makes its way into the crankcase, in times past this was vented to atmosphere, but recently it's not been considered cool 'n groovy to chuck various hydrocarbons and fractions of incomplete combustion into the air, so it goes into the airbox where it's drawn into the motor and burnt. Also if the crankcases were unvented, blow-by would increase the pressure in the cases and oil leaks would be likely amongst other problems.
2) Crankcase pumping - when the piston goes downwards the space above it expands, unsurprisingly the space below it does the opposite. If you have a multicylinder engine where the pistons move opposingly, like an inline four - two at the top, two at the bottom, as each falls and reduces the volume of the crankcase, another rises and expands it, thus the overall volume of the crankcase is unchanged.
With a V twin like an SV; common crankpin, 90ᴼ between the cylinders, when one piston is at the top of its travel the other is at midstroke, turn the engine one revolution and one piston is back at midstroke but the other is now at the bottom of its travel - thus the crankcase volume expands and contracts by the swept capacity of one cylinder every time the engine turns, in the case of an SV650 nominally 325cc. That's quite a sizeable pump, and when the engine is spinning at a reasonable rate, (6000rpm is 100 revs a second), inside the cases is far from calm and serene, and there's loads of oil mist being thrown around which that handy pump would want to chuck out of the way, hence my SV1000 having two big fat crankcase breathers and an oil separator to get that oil back into the motor, (the box into which the breathers go on the base of the airbox is baffled so oil won't pass through it*), instead of blown all over the scenery, whereas my ZX-6 has one weeny little breather pipe as there's much less crankcase pumping to bother it.

*Yeah, right.

Originally Posted by Sid Squid

Two reasons, one of which is very important to an SV due to the way it's constructed.
.

I'm not entirely sure this is relevant but fallout now rides a gsxr 750 not an SV.

[Sid Squid]

Originally Posted by Spank86

I'm not entirely sure this is relevant but fallout now rides a gsxr 750 not an SV.

I wasn't sure what bike was being discussed, but quite fair to point that out - I didn't know what the bike in question is.
I thought it relevant on an SV forum, whatever's being discussed, and as the above is written in reply to question as to the function of the breather, it seemed entirely worthwhile making it plain what and why what does what.

Tbh your explanation went over my head after that line, I thought I'd point it out as I wasn't sure how much of your explanation was transferable between bikes