Starter motor improvement
- Thread starter RCruiser
- Start date
I'm a little late to the party with this. It looks very much like a few of us have gone down the same route.
I'd been having problems with compression lock ever since swapping over to the HT-b and had to rock the piston over TDC on many occasions, so I anticipated worse problems once I went to 477.
My relay is the same as fitted to my Yamaha MT01 but looks to be fairly generic across several marques/models.
I figured if it's man enough to crank a 1700cc V-twin, it'll handle my recently fitted 477 kit.
I also used 8awg cable as per the MT01, pure copper terminals and soldered them rather than crimped. I re-routed them to keep the cables as short as possible and found it possible to halve the length of the cable from the solenoid to the starter motor. As I had enough cable, I also swapped out the battery earth for 8awg at the same time.
The started motor is definitely happier and hasn't failed to turn over the bigger piston so far, it's also nice to have the fused auxiliary power feeds to aid tidying up the wiring.
I'd been having problems with compression lock ever since swapping over to the HT-b and had to rock the piston over TDC on many occasions, so I anticipated worse problems once I went to 477.
My relay is the same as fitted to my Yamaha MT01 but looks to be fairly generic across several marques/models.
I figured if it's man enough to crank a 1700cc V-twin, it'll handle my recently fitted 477 kit.
I also used 8awg cable as per the MT01, pure copper terminals and soldered them rather than crimped. I re-routed them to keep the cables as short as possible and found it possible to halve the length of the cable from the solenoid to the starter motor. As I had enough cable, I also swapped out the battery earth for 8awg at the same time.
The started motor is definitely happier and hasn't failed to turn over the bigger piston so far, it's also nice to have the fused auxiliary power feeds to aid tidying up the wiring.
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The 477 alone only adds about 5-10% to the compression over the 411 as repeated measurements have shown. The missing decompressor alone is the culprit here, however we had a cam made similar to the HT-b but with decomp and the power gain was considerably less (thats why we do not offer it). I still run one test version in one of our 477 and this bike always starts on first push.
My "main" bike, a BS6 with ht-b and 477 hardly ever starts on first push of the button, but I also hardly ever need to push it in gear, for some reason the first futile starting attempt usually repositions the piston enough so the second pressing of the start button gets the job done.
btw: yours is a BS4?
My "main" bike, a BS6 with ht-b and 477 hardly ever starts on first push of the button, but I also hardly ever need to push it in gear, for some reason the first futile starting attempt usually repositions the piston enough so the second pressing of the start button gets the job done.
btw: yours is a BS4?
Yes it's a BS4.
Another thing I noticed on my original solenoid was that the insulation on switching wires for connecting to the start button and clutch wires had cracked all round at the resin base. It would only have been a matter of time before they eventually corroded and broke.
Going with the Yamaha relay has been a pretty cheap fix, and fingers crossed, it seems to be an improvement over the original.
Would you mind describing how to do these?
For the clutch switch jumper the gray and black wires together at the clutch switch connector.
To bypass the side stand circuit the best way is to do it at the relay by jumping the black wire and the white/blue wire. This will allow you to eliminate the need for the relay. Do this at your own risk as the bike will start in any gear without the clutch being engaged. I grew up without any of these safety features and feel I don’t need them on this bike.
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