[Zac Agee]

So everyone thinks what....? That bits of the magnets did what? - bend or seize the intake valves.. is that the assumption? No one has actually come out and said what they think is really wrong here unless I missed it. I'm not 100% solid on whats wrong - I'm thinking it could be electrical because even with 2 weak cylinders the bike should start. We are all assuming that the readings are correct at this point. If that's the case then I would have someone manually turn the motor and look down into the head on the intake side while your valves are opening and closing and see if you can see anything fishy. If it is so bad that it won't run it should be obvious if its an intake valve you would likely see it not move at all / missing / or bent. If you took the intake valves out of one of the cylinders the bike would still run... poorly but it could be 'rideable' with two dead cylinders (And I mean completely dead - no compressor) it would sound like it wants to try to start but will only do so with a fair amount of throttle... Since two of the 4 cylinders aren't making compression if they are completely dead, usually the motor can or will try to idle since its got 2 less cylinder's worth of compression to work against. At any time when you tried to start this thing after it went south did it backfire at all??

I don't want to ad confusion - but I'd like to get my head around whats going on with this motor.

Yep your lost.. Lol
After showing him proper procedure results are to much leakage at the intake valves..
And no way in hell a stator magnet coming apart is gonna bend a valve lol and no its not gonna run if you remove and intake valve! Be shooting a fireball out the intake side! On an inline 4 you can drop 1 cylinder it will run drop 2 cylinders you just killed half of the combustion cycle and depending on what 2 you don't have enough rotational force to even keep the crankshaft in motion.
Simply he's got a loss of compression in 2 cylinders on the intake valve side be it bad seat or bent valve and at about 50% loss each it's not going to want to run
#1 was 45% leakage intake side #4 was 58% leakage intake side..
This all comes from a machinist background an engines an engine Simple
you'd be amazed the stresses valve train parts take at higher rpms.

And it's very hard to diagnose something without being hands on or seeing the procedure done to know it was done right.. That's why I had him watch a video of a cylinder leak down on an r1 for confirmation.. Now maybe I shoulda second guessed him sooner but we're all human ?





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[quick kurt]

intake valve bent
you'd be amazed the stresses valve train parts take at higher rpms.






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Most likely the reason for the entire thread there...I'm guessing the OP hit the rev limiter and tagged a few pistons (at least 2) when the valves 'floated'....and also the reason I had ALL of my valve springs replaced while my '06's head was off, that and the fact it already had 42k miles...:icon_wink:

 

[avj3]

Alright, so the motor is out. Took a little longer than a half hour to get all the hoses and electrical connections loose. I have not taken the head off. I see there is some question on how the leak test was done. I made the below video to show how I did the leak down check. Please take a look and let me know if you think I did something wrong. Not sure how to embed the video so links provided.

I plan on pulling the head tomorrow if everyone still believes this is the problem. Off to paint the babies room now.

Cast of the video includes myself and my little helper Maya (she is the black fury one). Videography is complements of my 6 month pregnant wife.

 

[Zac Agee]

Avj3 that confirms it the intake valves are the culprit!
Wasn't doubting you after I sent you the first video of a cylinder leakdown?

Also when you do change the head buy a new timing chain and tensioner weather you go manual or oem and if needed the guide also

Anyways once the heads off let's see the damage


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[quick kurt]

You can pull the intake cam out and retest leakdown on cyl. 1&4, before removing the head. If anything broke in the bucket area under the cam, it could hold the intake valves open, that is the reason I suggest to retest before pulling the head. A valve shim possibly could've dislodged, or retainer broke or another part. With the engine at TDC on 1& then 4, look into the intake ports, and look for any wear on the valve stem(s) in the area the stem is protruding from the valve guide. If the valves are fully closed, there should be no visible wear on the valve stem where it travels through the guide. If wear is visible on the valve stem, that valve isn't closing 100%. Spraying WD40 or similar around the valve seat area(with valves closed) will show which valves are leaking, and you'll know exactly where the problem valves are. Great wife you got there, Good Luck with the job.

 

[ChR1z]

I'm with you guys now..I didn't watch the video. FYI - When I said you can remove the intake valves and the engine will still run I meant that in a less than literal way, what I should have said was that a valve can seize wide open and the engine will still run. I have seen many inline 4s run with two dead cylinders. Most did actually but I don't recall which cylinders where down and what the firing order was. I'd say more but I don't want to derail OPs thread.

Bouncing off the limiter w/ no load and smacking a valve makes good sense and that was my original thought although at the same time I didn't think based on his description that he rev'd it THAT much. With all the stunt guys constantly free revving their motors I'm surprised they don't float, seize and bend more valves than they do.

Good luck.

P.S.
Have I mentioned how much I hate the charging and starting config of that motor? First year grad student design I swear.

 

[SPanega SS]

Any word???

 

[avj3]

Pulled the head today. Prior to doing so I checked out each valve shaft in the closed positions and saw no visible wear on the stems. I repeated the leak down check with the cams removed. I put WD-40 in the intake valve seats as recommended. All three intake valves on #1 and #4 were spitting the WD-40. The two worst were the outside most valves on both #1 and #4.

So I continued with the pulling the head. There was no visible damage to either the valves or the pistons other than gross carbon deposits on the valves and head near the valves. I pulled the intake valves on both #1 and #4 and did some cleaning, have the valves sitting in sea foam overnight. I will post pictures tomorrow.

My plan is to put the head back together and see if my cleaning caused a significant change in the compression and leak down check. If so I will put the motor back in and see what happens, of not I will look at a new head.

 

[avj3]

So they are not bent?

Nope. No damage at all. Still no smoking gun...

 

[ChR1z]

Nope. No damage at all. Still no smoking gun...

I was afraid of that. I don't want to ruffle any feathers so I'm biting my tongue until I feel I've got something useful to say but let me ask did the motor ever back fire since it went south? I was editing my post when you quoted lol. Sorry about that. Can you see down into the cylinders and see if there is any scoring on the walls?

Let me ask you another question... When the bike was dying on you did you leave the clutch out at any point and throttle it? If so did the engine respond at all and if so what did it do? Also if you did engage the clutch and the rear wheel wasn't locked, did you hear any odd sounds coming from the motor at that point?

If the cylinder walls are clean, then I think there is no need to go any further. Maybe the chain stretched or it hopped a tooth as speculated. Timing on those bikes is a bit ambiguous if you have not done it before (came timing of course). Usually if you just jump one tooth retarded or advanced it will still run.. just fall on its face somewhere in the rev range depending on valve overlap... But I digress... If the cylinder walls aren't scored put it back together. I would. You're gonna need a head gasket set of course and you can adjust the valves while you are here. Might as well. More minds are always better so lets see what the resident experts think...

 

[avj3]

I was afraid of that. I don't want to ruffle any feathers so I'm biting my tongue until I feel I've got something useful to say but let me ask did the motor ever back fire since it went south? I was editing my post when you quoted lol. Sorry about that.

The bike never backfired. Didn't here it when it stalled and it certainly never did it while I was trying to start it afterwards. What are you thinking?

 

[ChR1z]

The bike never backfired. Didn't here it when it stalled and it certainly never did it while I was trying to start it afterwards. What are you thinking?

Backfires can hint at valve timing problems or excess fuel sitting around not getting burnt how or when it should. When the bike was dying did you have the clutch in or out?

If it was out did it try to pull AT ALL even intermittently...? Did you try WOT at any point during the rolling death?

 

[avj3]

Backfires can hint at valve timing problems or excess fuel sitting around not getting burnt how or when it should. When the bike was dying did you have the clutch in or out?

If it was out did it try to pull AT ALL even intermittently...? Did you try WOT at any point during the rolling death?

Clutch was in I believe. The bike ended up in neutral somehow and the motor had stalled, so no WOT. It just coasted to a stop with motor no longer running.

 

[ChR1z]

If it was me at this point, I would check the walls for scoring and if you don't see any gently use the cam chain to spin the bottom end and watch the pistons move up and down. It might take a tug to get it moving but once you do if anything is wrong it obvious between scoring or nasty movement. If you see no scoring than I don't think you have a problem that requires case splitting. I am assuming the neutral light is on? Not just feeling like neutral. Correct?

 

[Zac Agee]

Pulled the head today. Prior to doing so I checked out each valve shaft in the closed positions and saw no visible wear on the stems. I repeated the leak down check with the cams removed. I put WD-40 in the intake valve seats as recommended. All three intake valves on #1 and #4 were spitting the WD-40. The two worst were the outside most valves on both #1 and #4.



So I continued with the pulling the head. There was no visible damage to either the valves or the pistons other than gross carbon deposits on the valves and head near the valves. I pulled the intake valves on both #1 and #4 and did some cleaning, have the valves sitting in sea foam overnight. I will post pictures tomorrow.



My plan is to put the head back together and see if my cleaning caused a significant change in the compression and leak down check. If so I will put the motor back in and see what happens, of not I will look at a new head.

You can't always see damage on the valve face and face of the valve seat with the naked eye sometimes you need magnification and or dye to see the dips and scares that cause leakage.. What I mean by this is you have 2 mating halfs that have to match that's where the dye comes in to see contact pattern.. You could lap them in and help but a true cure is take the head and valves to a machine shop and have them regrind them.

One of my favorite things back at the machine shop was grinding titanium valves the bright white sparks are something of there own?


Oh ps each valve have to go back in there respected place of removal or you have to lap/ regrind them or they will leak


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[ChR1z]

You can't always see damage on the valve face and face of the valve seat with the naked eye sometimes you need magnification and or dye to see the dips and scares that cause leakage.. You could lap them in and help but a true cure is take the head and valves to a machine shop and have them regrind them.

One of my favorite things back at the machine shop was grinding titanium valves the bright white sparks are something of there own��


Oh ps each valve have to go back in there respected place of removal or you have to lap/ regrind them or they will leak


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That's true but do you believe that the valves are stopping the engine from running at this point? I'm just asking. Like he said... I don't see a smoking gun either...

Please don't think I am trying to discredit anyone - you or any one else. While I feel I know quite a bit, til the day I die I'm always learning. I don't wrench on bikes professionally. I have built a few of my own motors top to bottom and I have worked on many different models. I used to buy, rebuild and sell bikes but that is too much of a gamble so now I paint bikes for a living. Less people specializing in plastics.

I see a bunch of magnet bits in the rotor and if any of them managed to whack the stator and cook any one of the 3 phase windings all bets are off. I am just saying I can't seem to get by that in my mind.

My father - the genius electronics engineer that he is (tongue and cheek) - used to say to me, "I didn't go to school to learn to use my eyes". I think it was his way of saying to me, troubleshoot what you can see as a problem first - then go chasing the ones you can't see. So I tend to come at things from that angle any more.

 

[Zac Agee]

That's true but do you believe that the valves are stopping the engine from running at this point? I'm just asking. Like he said... I don't see a smoking gun either...

I see a bunch of magnet bits in the rotor and if any of them managed to whack the stator and cook any one of the 3 phase windings all bets are off. I just saying I can't seem to get by that in my mind.

Ok first off you can run the bike without any of the stator working and or being busted purely off a charged battery! In fact the manuals have you unplugs them and test the ac output while it's running..
Ok now onto what makes an engine run simple as this all an engine needs is air, fuel, compression, and spark.. Higher your compression the bigger explosion you wind up with due to the compressed air and fuel plus the heat that is created all set off by the spark! You lose compression you have no energy from a cylinder.. No compression no explosion you wind up with a small slow burn that does nothing..
Ok now we already know the OP has spark he's tested that we know the motor has air beings there is nothing wrong with his cams and obviously his throttle bodies are gonna let air by that leaves fuel and that's the only questionable thing I still have but even then I'll prove my point shortly.. But he's lost 50% compression on 2 cylinders! Worst of all the 2 cylinders on the same plane or "throw" of the crankshaft so essentially hes got 2 cylinders for an entire combustion cycle! That's 2 complete revolutions of the crankshaft!
Now add in the factor high performance engines with high compression suffer even more when you do lose compression because they have so much more valve overlap that technically your rotational compression is lower then static compression numbers from this factor you lose even more compression and said energy! Another factor here this isn't some Toyota or Honda car engine that idles around 850rpms these bikes idle 1100-1200 for a reason they get really unhappy and choke out under 1k rpms now your starter don't turn the engine that fast to begin with they require the extra fuel on fire up along with your compression to make enough energy to fire off at first!


Not to derail this but this is real life proof without compression you have nothing in an internal combustion engine! This just happens to be something I finished today and make good example
Ok to prove my theory here this is a 2 stroke chain saw engine meaning the cylinder builds compression and fires every 1 rotation instead of 2. in the pictures below is a slightly scored cylinder right above the exhaust port obviously droping compression now this engine only lost approximate no more than 1/3rd of its compression was running then just bogged to a stop literally all that killed it was lack of compression.. Swaped a new cylinder on fired first pull.. My point here is you may think oh it's only 50% leakage out a valve but it's so much more energy lost as a whole!

Hope that all makes sense but Anyways not trying to be a dick but one thing at a time none of us are there besides the OP but on a mechanical standpoint stators not gonna keep it from running if the batterys charged and it has fuel, air, spark, and compression!


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[ChR1z]

Ok man - I'm with you. Thank you for taking the time to let me know where you were coming from on this. Firing order on this motor is 1 3 2 4 correct? I know he's got spark but is it on all for cylinders? I've gotta go back and recheck that. I will admit, I've seen some pretty torn up engines that were still running BUT none of them had an obvious damage to valves / valves seats, rings etc..

So at this point you think the seat got hammered somehow when it was REVd?


Pics of the back of each of the valves and the underside of the head so we can see the seats would be groovy!

I'll back off and let you do your thing man.. I just wanted to get my head around this action - that's all.

Props for taking the time and always having good references like the info you linked for LD testing and photos like this last one. It helps folks out quite a bit.

 

[Zac Agee]

Firing order is 1 2 4 3 as per the manual


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[Zac Agee]

Firing order is 1 2 4 3 as per the manual

You've seen tore up engines... I've had my sprint car engines come back missing half a cylinder head from droping a cylinder! Had an nhra car come back with 6 of 8 intake valves snaped off due to over revving across the line.. High performance is a fine line it all has to work together or you got nothing.. Not like an average engine.


P.S. Nothing better then methonal fuel burning your eyes and skin and that sweet smell lol

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