View Full Version : Results of tonights tinkering ...
Fallout
17-10-12, 07:33 PM
Thought I'd do my compression testing tonight. As usual with maintenance, didn't go 100% according to plan. Can't be arsed to tell a story, so here are all my observations ...
- Universal compression tester isn't universal. It doesn't fit. What a bunch of scrotum. So no compression testing performed.
- Bike started fine this time. Perhaps low battery last weekend as I hadn't plugged the optimate since Wales because socket was in use.
- 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.
- Oil on the air intake valves. Just a little.
- 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.
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.
Anyway, at least starting issue is resolved so I don't anticipate problems with not making it to rideouts this winter. \\:D/
Thunderace
17-10-12, 07:41 PM
What are you gonna do with the compression tester?
Wideboy
17-10-12, 07:43 PM
they are breathers for the Gearbox and possibly the crank casing, i cant remember why they are linked to the airbox but yes i believe its to do with back pressure.
also when something is amiss (like everything on your bike, your list, nuff said) they can fill the airbox with oil which in turn will get drawn into the pots, may explain your smoking problem.
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.
My 650 had a breather pipe fall off the airbox and this caused oil to drip. You should find a PDF somewhere showing where all the breathers go. Worth checking none are blocked too. Should mostly be 6mm vacuum tube. I've found a local supplier who sell it by the meter for not too much and they do it in lots of colours too if for example you want them in orange to match those funky wheels. If they have been randomly plugged into the wrong place it can lead to weirdness.
Fallout
17-10-12, 07:57 PM
What are you gonna do with the compression tester?
Keep it for cars. Think I might use it on the Mondeo and see if I can diagnose what's going wrong with that piece of shiz. Apart from smoking at start up, it struggles at around 2.5k rpm when cold. Fine after a few minutes, but stutters and loses power when cold while spewing out crap. Stalled once in the middle of a traffic light crossroads too. I wonder if 2.5k rpm is when the turbo starts picking up speed ...
they are breathers for the Gearbox and possibly the crank casing, i cant remember why they are linked to the airbox but yes i believe its to do with back pressure.
also when something is amiss (like everything on your bike, your list, nuff said) they can fill the airbox with oil which in turn will get drawn into the pots, may explain your smoking problem.
Interesting gavster. Perhaps that's where some of my oil is going. It'll be interesting to see if there are any changes next time I ride it.
I think if i found out the things you've found out about your bike mate i'd be rolling around on the floor crying in blind panic/worry
Fallout
17-10-12, 08:00 PM
@Mark - I'll have a look in the Haynes and see if the pipes are mention. May save me a few ml of oil each journey now it's back on.
Fallout
17-10-12, 08:02 PM
I think if i found out the things you've found out about your bike mate i'd be rolling around on the floor crying in blind panic/worry
:smt046 None of it is a big deal. Tyres + brakes are the only thing you should really worry about. If they fail, they'll kill you. Most other things failing will just result in a bad day.
Edit: Tyres and brakes and axles done up properly for staying alive, oil in the engine to avoid expensive damage, everything else is meh!!
Littlepeahead
17-10-12, 08:02 PM
Why don't you just buy a nice BMW. Car, bike, better still both.
Wideboy
17-10-12, 08:04 PM
Interesting gavster. Perhaps that's where some of my oil is going. It'll be interesting to see if there are any changes next time I ride it.
possibly but it shouldn't be burning a noticeable amount that needed topping up, i would say your bikes just an oil burner, or maybe the wrong oil? if the oils to thin it can slip past the rings (teehee ring). My ace had the wrong stuff in it when i bought it, it burnt its entire oil in about 300 miles.
worth checking if all else fails, want me to have a hunt for my compression tester? i can't remember what size it is but im pretty sure i last used it on an old stroker so should fit
Ref the iffy plug threads, if you still want to take the heads off you may be able to get them re-tapped or if fully buggered get them helicoiled. Should not be too expensive either way.
May be worth checking with the bodgers ref some sort of threadlock between now and doing it properly both to provide a better seal and stop them working loose.
Fallout
17-10-12, 08:09 PM
Why don't you just buy a nice BMW. Car, bike, better still both.
Money. :rolleyes: ... and taste.
possibly but it shouldn't be burning a noticeable amount that needed topping up, i would say your bikes just an oil burner, or maybe the wrong oil? if the oils to thin it can slip past the rings (teehee ring). My ace had the wrong stuff in it when i bought it, it burnt its entire oil in about 300 miles.
worth checking if all else fails, want me to have a hunt for my compression tester? i can't remember what size it is but im pretty sure i last used it on an old stroker so should fit
It's possible. I just got 10w/40 as specified in Mr Haynes, semi-synth Castrol. A few people have suggested thicker mineral oil. I could try that at the next oil change, though wouldn't know what to look for. I'll see if Mr Haynes says anything.
As for your comp tester, if you can dig it out mate that would be ace! Save me buying another kit! :rolleyes:
Wideboy
17-10-12, 08:11 PM
cant promise anything, not seen it for about 5 years and didn't see it when we moved last year
Fallout
17-10-12, 08:11 PM
May be worth checking with the bodgers ref some sort of threadlock between now and doing it properly both to provide a better seal and stop them working loose.
I don't think that's necessary mate. I think I was just paranoid about stripping threads so didn't tighten them up enough. I've given them a good tightening this time without going mental. I'll check them again in 500 miles or so and see if they're still in properly. :smt045
Spank86
17-10-12, 08:22 PM
Change your oil for castor oil, if nothing else you'll get to see anyone that rides behind you running for the loo.
Fallout
17-10-12, 08:26 PM
I was thinking about crude oil. That's quite viscous isn't it?
@Gav - no probs mate. If it turns up let me know!
Change your oil for castor oil, if nothing else you'll get to see anyone that rides behind you running for the loo.
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?
Thunderace
17-10-12, 08:28 PM
it struggles at around 2.5k rpm when cold. Fine after a few minutes,
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
i can't remember what size it is but im pretty sure i last used it on an old stroker
Why were you using it on Mark?
Thunderace
17-10-12, 08:29 PM
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?
I very much doubt that Ad's new beasty is in very good condition all over, very envious!:smt078
Wideboy
17-10-12, 08:30 PM
oooowwww
Fallout
17-10-12, 08:32 PM
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! :rolleyes: 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. :)
Spank86
17-10-12, 08:35 PM
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.
Thunderace
17-10-12, 09:04 PM
Good advice. I've been doing that a bit. Pretty flippin tedious I can tell you! :rolleyes: 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
17-10-12, 09:10 PM
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.
Thunderace
17-10-12, 09:14 PM
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!:rolleyes:
Wideboy
17-10-12, 09:21 PM
i'll giva ya a pand
Sid Squid
18-10-12, 09:53 PM
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.
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?
Oil on the air intake valves. Just a little.Where specifically?
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?
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.
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.
Spank86
18-10-12, 10:04 PM
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
18-10-12, 10:19 PM
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.
Spank86
19-10-12, 06:53 AM
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
Fallout
19-10-12, 06:58 AM
Doesn't matter if I have a gsxr 750. That's still a good read Sid and lots of useful nuggets of info in there. It still applies, albeit in slightly different ways. :)
Loose and tight until they bottom out, or just loose and tight forever and ever?
The former, luckily. The threads aren't destroyed, just showing signs of mild over-tightening/cross-threading. Eventually all plugs bottom out. I've just given them an extra bit of torque this time round to keep them in.
Where specifically?
Where the airbox connects onto the throttle body (I assume it is - not sure on names), the 4 valves there have some oil build up. There is also signs of some oil in the airbox and around the general area. The pipe that wasn't connected was the central one to the airbox, which came from low down in the engine. Only had a quick look. Not sure where it was from exactly. My thoughts at the time were down near the gearbox, but could've been low in the crankcase maybe.
If it's the one I asked about above, then no, it doesn't.
Probably started better because my spark plugs are in better now! :)
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