Kochan

The bike starts with the side stand down when in neutral, but does not rev over 5k (the cam shafts are currently on the new chains, aligned with the cylinder head position). When in the other position (look at the drawing above) there is no spark.

I haven't looked at the cams position when rotating the camshaft yet. Thanks for the tip Terry. And it's not a problem with VTEC, at least not mechanical... It does not rev above 5k.

I talked to my mechanic friend. There was no spark - because computer blocked the normal start sequence. When pushed, the computer omits those blockades apparently. This is how he explained this.

Just to visualise the position of the rear camshafts.

Yeah, right.

Yes, there was no spark. Maybe I'm wrong but It kinda does makes some sense to me... It looks like in this position of the cam shafts, the computer does not allow the bike to start by not sparking. That's the question. I think the computer is not initiating the start when cam shafts are in bad position = bad timing from the computer perspective? Not sure, we can check. We just replaced the battery so it's new. No, I asked if at every turn of the crankshaft the pistons are in the same position, but it was stupid question... As in the manual, when setting the timing, you set the crankshaft to 3T, set the rear, move the crankshaft clockwise by 450 degrees and set the front. It's hard to mess up... But something is wrong anyways.

Hi Terry, I have an idea... What would happen if after removing the cam chains, the crankshaft would be rotated 360 degrees and then set as in the manual? Would it start? How would it behave? Any idea?

No, the crankshaft was in the correct positions 3T/4T during replacement and was not moved... The only thing that affects this position is chains. The old chains are slightly more loose, the new ones are bit more tight. On the old chains (the bike starting and working properly) On the new chains (the bike starts, but does not rev over 5k): WhatsApp Video 2024-04-19 at 08.56.56.mp4 When we move the cam shafts slightly forward, then the bike does not start but when push-started, revs over 5k... Loosing my mind here... 🙈

Hi @Grum, thank you for the quick answer. The valves adjustment was just done so they are all in spec. I'm not sure about the other things... Because the behaviour depends purely on the position of the cam shafts. If they're aligned correctly, by the book - the bike starts but does not rev over 5k - which indicates wrong timing. When the position is adjusted by one sprocket tooth forward, as on the old chains (when the bike was starting and operating fully) the bike does not start by itself but when push-started, it revs fully indicating the correct timing... Indicating the problem with start sequence Is it possible that the computer somehow "learns" the position of the cam shafts vs crankshaft?

Hi guys, This thread is a continuation of the archived thread After months of a bike staying in a garage, and me collecting mental energy to deal with the issue once again, I decided to give it another try. After trying to test many different components and confirming the connections to all sensors and trying all suggested solutions by all the great members of the community I gave it to a friend, who is a professional mechanic. The first thing he tried was to push-start the bike and... it worked! The bike started and worked as normal but it can't start on its own. The next thing he checked was cam chains timing and here he found that the timing was a little bit off - the cam shafts were one sprocket tooth forward comparing to what's in the manual. So he adjusted the position of the cam shafts and... the bike started. But this time it won't rev over 6k. The new chains were DID chains so we suspected that maybe the DID chains do not fit perfectly, and decided to order original MORSE chains. The differences between DID and MORSE chains were: - the DID chains seemed very tight - the cam chain tensioner did not have too much room to unfold but the bike did not rev over 6k when cam shafts were aligned perfectly by the book - the MORSE chains seemed a little more loose (as expected) - the cam chain tensioner had a little more room to unfold but the bike did not rev over 5k when the cam shafts were aligned perfectly by the book So here is the situation. On the old cam chains, it's impossible to align the cam shafts marks perfectly with the cylinder head as it says in the manual. The position is slightly forward (clockwise) and then the bike operates normally. On the new cam chains, when the marks on the cam shafts are perfectly aligned with the cylinder head, the bike start's but won't rev over 5k - MORSE, 6k - DID. When the position is adjusted by one sprocket tooth forward, the bike won't start by itself but when push-started it operates normally. Both me and my mechanic friend are out of ideas and are going crazy over this issue... Do you guys have any ideas? @Grum my dear friend? 🙂 Thank you all in advance!!

Right? I found a diagram for my model. There should be bolts holding the chassis together. I have to manage this first, to get full access to the ECM. I will measure the suggested wirings, and get back to you with the results.

Thanks @Grum I will definitely check those connections as soon as I figure out a way to get to the black ECM connector. As I mentioned, the ECM is fixed in a metal chassis that prevents the black connector from being unplugged and the bolts connecting the front ant back part of the chassis are broken. I don’t see other way to access the ECM than to unscrew the broken bolts and separate the chassis.

Regarding the green wire in the blue connector mentioned before - resistance to the negative battery terminal: 0.4 - 0.5 Ω from both sides of the connection - voltage measured to the positive battery terminal shows battery voltage

The thing is that it does not look like it... This metal "chasis" is made of 2 elements that seem to be permamently fixed together. There are no bolts and It looks like it's fixed or there were bolts and they're broken. Very strange. I'll try to figure this out... In the meantime I've measured the light-grey ECM connector against the battery positive and negative terminals. Here are the results.

Thanks for the photo @Grum I have the Service Manual. I thought that maybe there was some other pin diagram available. Regarding the ECM removal, there is nothing about removing the metal plate, that locks the ECM in place, in the manual. I can see no screws so I'm wondering how do I remove that.