Firestorm struggling to start

[shammi]

I have a '99 Honda VTR Firestorm (SuperHawk996) which has been suffering from starting issues for the past month. Sometimes it would start without any issue over and over. Sometimes it would start once but if we turn it off and try again, the issue would come back even if we let the engine warm up by running the bike for several minutes. So from what I can say, heating it up wont make the issue go away. I have recorded the issue when it came and uploaded it here on YouTube for your reference:



Our first thought by the flashing instrument lights was poor battery. So we bought one brand new, hooked it up and the issue was still present. We tested this new battery by putting it up on a charger and it charges and holds up very well. So the new battery cant be at fault. We even borrowed a second battery and tried starting and this issue would still come. Put our new battery again and tried jump starting with the help of a car battery and still had no change.

Next we went through the wiring towards the starter and noticed it had slight damages. We replaced it with a new one. Along with it we replaced the ground wire of the bike. Even after all of this the bike still would not start. We then took apart the starter motor, cleaned it up and replaced the brushes. Put it back in and still no improvement.

We then had a look into the spark plugs and they were good as well. We then decided to see if the engine would turn over if we hit start while the plugs were out and when we did this the engine turns over effortlessly. However if we even put back at least 1 plug, the bike would struggle to turn over as shown in the video.

We removed the crankshaft cap and tried turning the crankshaft with a spanner wrench and noticed it was very difficult to turn when u have turned around 180°. We have a suspicion if this is putting a huge strain on the starter motor and it is struggling to turn the engine. However we are unsure if this is how it normally is or if something is causing it.
(The starter motor I believe is OEM, its a Mitsuba SM-13 12v starter motor.)

If anybody can provide us some guidance we would greatly appreciate it. Thank you.

P.S: We have used 20W 40 engine oil in our bike. The manual says to use 10W 40. We thought this is ok as we live in quite a hot country and have no winter here. Could this be an issue too?

[tony.mon]

Starter motor transfer gears.
There's a thread in the workshop knowledge base about this and how to replace them.
Macv2 has spares if you need them.

[MacV2]

Starter motor transfer gears.
There's a thread in the workshop knowledge base about this and how to replace them.
Macv2 has spares if you need them.

A spare being stored in the 'just in case I need it pile'...NFS

[shammi]

Starter motor transfer gears.

Could it be though as it is able to turn the engine when the plugs are removed?

[shammi]

There's a thread in the workshop knowledge base about this and how to replace them.

BTW is this the guide you were referring to?
https://www.vtr1000.org/phpBB3/viewtopic.php?t=20849

[tony.mon]

Starter motor transfer gears.

Could it be though as it is able to turn the engine when the plugs are removed?

Yes. One gear turns against the other under a torque load. Without plugs there's no compression, so there's a considerably lower torque load.

[shammi]

Starter motor transfer gears.

Could it be though as it is able to turn the engine when the plugs are removed?

Yes. One gear turns against the other under a torque load. Without plugs there's no compression, so there's a considerably lower torque load.

Hi, so today after running around for finding the proper tools to remove the flywheel we got upto this point shown in the image with the flywheel removed. We didn't have the time today to get the gear wheels that go towards the starter motor removed. So was wondering if the usual fail point is at the small gear wheel shown from the red arrow in the image.

[tony.mon]

Yes. There are two gears, one is pressed onto a shaft fixed to the other. They should stay fixed together but one can rotate instead of staying fixed together under a high torque load. You won't be able to replicate it happening outside the engine.
Simply remove and replace the pair of gears.

[shammi]

Yes. There are two gears, one is pressed onto a shaft fixed to the other. They should stay fixed together but one can rotate instead of staying fixed together under a high torque load. You won't be able to replicate it happening outside the engine.
Simply remove and replace the pair of gears.

We got them welded and the bike starts first round. I have recorded how we did it, will post a video of the process hopefully by this weekend.

Thanks for the support guys

[tony.mon]

I bought a perfectly good storm from a so-called mechanic a few years ago for £400, and had it running perfectly an hour and a half later with this fix. He'd spent days on it, replaced the sprag clutch, all sorts.
I called him afterwards and told him was it was, he didn't seem grateful.

[shammi]

Here are the videos on how we fixed the issue
Part 1:
Part 2: