Yamaha R1 starting trouble: How I found the cause & its fix!

Have to now find a starter motor assembly, until which time my superbike is out of commission.

BHPian krishnaprasadgg recently shared this with other enthusiasts.

All is not well with the R1.

Riding has been less, only a few 20kms round trip runs on Sundays just for the sake of keeping the bike running have happened since the last longer ride. And of this a couple of weeks back during one such day while trying to take the bike out it refused to crank up properly, almost like the battery wasn't charged up. The meter would switch off while cranking and the starter motor would go dead without getting juice. But this was not possible because the bike has been hooked on a battery tender the previous day and was fully topped up.

This started to give me signs that probably the battery is not able to handle load but it is still retaining charge.

Here is a video of what was happening

As you can see the meter goes off, and the starter motor does not have enough juice to crank the engine.

I wanted to check the volt readings but my multimeter was packed away somewhere and me being lazy I put it off and 2 weeks had passed, and yesterday I finally fished it out. Mind you the bike has not been on a battery charger for these 2 weeks. I didn't hook it up to a charger before the test yesterday because I wanted to test the resting volt before and after fully charging the battery

So, I got out the multimeter and checked the battery volt and it sat at a healthy 12.6 V. And then hooked up the battery charger and the battery was fully charged in about 1-2 hours. So I am assuming it has not lost too much charge over the 2 weeks.

Then I began the test, I checked the voltage and it was again 12.6V and then I proceeded to check the volts while cranking to see how far it dropped, the first time I checked it dropped to less than 6V but I could not manage to get it on video, I assumed I had hit record but hadn't. So I try again and here is the result.

As you can see it goes to 8.xx V as the lowest value.

Now since I have a Battery Jump Pack I hook it up to the battery, which btw is a bit of a bother, the rider seat and the plastic panel on the subframe need to come off and the battery needs to be taken out of its resting cavity so that I can hook up the alligator clamps onto the terminals.

When I hooked the jumper pack up and cranked the bike cranked right up, no resetting of the meter happened, and a very normal voltage drop too. Here is the video.

Now the next step I just wanted to check the condition of the charging system to see how much the volts read when revving the bike and to rule out overcharging and any potential damage to the stator coil or RR unit.

Here is the output with short blips

Later I left the bike idling for about 20 minutes and returned back and checked the readouts while revving it past 3k rpm since that's the rpms above which the battery actually gets charged(I think, correct me if I am wrong here)

And this was the output

Don't mind the sudden drop that was because the probes on the multimeter got a bit loose, it was tough to handle recording holding the probes, and revving with just me trying to do all of them.

Anyway, to sum it up, I think a new battery is in order, the Varta I have been using is almost 2 years old since fitment and now it's starting to let go. I have ordered its replacement, and this time I chose the BS BTZ10S SLA. This has a higher CCA of 190A as opposed to the 150 of the Varta TTZ10S I was running.

In between all these tests, I also noticed that one side of the battery had started to bulge. Which was alarming. Good that I actually noticed it.

Won't be risking using this battery anymore, I should be getting the replacement battery in a day or two and will repeat all these tests again post-installation and will report the findings here.

The reason I am checking this again is because of the readouts the battery gave when the bike was revved above 3k rpms, Ideally, it should have been 13.8 or slightly higher, that's the optimum reading for a healthy charging system I have been told. which was not seen, so that leads me to think maybe the charging system is also being strained because of the battery and. could be on its way out. After all, it is an 11-year-old bike at this point. So need to do some more detailed voltmeter checks at the pinouts of the Stator coil and RR unit. But no point in checking that with a bust battery, so will wait until I have the new battery in place and fully functional. There is also a possibility that I am overthinking this and the readout was slightly low because of the battery being bust alone. That doubt also can be cleared once the new battery is here anyway. So the bike will be out of commission up until that point.

P.S: The lack of Li batteries availability in the country right now is very very infuriating, alas not much that can be done from the looks of it.

BHPian krishnaprasadgg updated:

So let me pick up from where I left off. The new battery arrives. And I get to fixing it up and post-fitting I try to do a startup and much to my dismay the bike more or less behaved the same.

Yup, so it was not just the battery after all. I say not "just" the battery because now the battery can take the load much better and the meter console is not switching off on load. Anyways. Took a few videos replicating the tests that were done before with the old battery as well. And the results were different for sure but the root cause remained the same.

Voltage shown with the BS battery before start-up

Here is the video

The bike refuses to start, but the bike does crank without much load issues, it is only after a couple of attempts the starter seems to be having an issue of not getting enough juice.

Once I do get the bike to start the charging volts all seem to be satisfactory and no issues at all in that.

Volts while checking for the charging volts

Then on the advice of Karthick, I take the bike out for a short 14-20 km ride and check the voltages again. The voltages seem to be just fine on idle it has 12.6 v

Here is a video of how the root problem still remains with the new battery

P.S Don't mind the video orientation going upside down mid-way.

But during all this I notice something. Once I get the bike going from a cold start then all subsequent starts happen easily without any issues at almost half crank itself. But I wasn't sure if this was a fluke or if it is repeating like this. So I decided to do a series of tests again.

So I repeat the test for a short ride and it behaves the same. On the first cold start of the bike, it takes multiple attempts before the bike finally cranks up, on average 3-4 attempts, and once the bike gets going and is ridden for some km, I can safely switch off the bike and switch it on again and it starts in half a crank no problems whatsoever.

By this time I had also a Bangalore ride coming up and I was debating whether to ride the bike to Bangalore in this condition or not. Considering there is a possibility of me getting stuck with the bike not being able to crank at all. So on the council of a few experts, I decided to make the ride to Bangalore anyway, I kept my jump pack with me as insurance just in case I was not able to get the bike started or by jump-starting the bike in gear this could save me. But I decided I won't be testing my luck too much and for the entire 500kms journey, I'll only stop twice for fueling once at Coimbatore and once at Salem, so that the stop will be only in proper fuel bunks where in case I do get stuck help will be easier to find. And I can work on the bike in a safer environment too, as opposed to somewhere in the side of the road along the highway which could prove dangerous.

So I plan on starting my ride early in the morning and yes, you guessed it, the bike doesn't want to start, but as expected by around the 3rd or 4th attempt I get the bike to start. And I set on with my trip, I stopped for fuel at Coimbatore, and post fueling I toggle the key and press the starter button with my fingers crossed and the bike starts up with just half a crank itself. I proceed to gear up and continue my ride, the ride is going absolutely fine and I stop at Salem again to refuel(This is just a precautionary fuel up because finding an XP95 bunk post Krishnagiri till Hosur or Bangalore is a bit of a pain without having to navigate those long blocked off service road situation) and the bike behaves the same at Salem too. Starts up back at half a crank.

Finally, I reach my flat without any drama and I park the bike in my parking. initially, the plan was to take the bike to Highlander once I was a bit rested but later on, after talking to another friend who suggested checking if it's a fuel pressure issue the first startup isn't happening without a struggle. So I thought I'd do one more test and I toggle the fuel pump on a few times before attempting a crank just to test this theory. So I leave the bike in my parking till around 9 pm, that's about 12 hours of cool time so the engine is dead cold. And the same behavior, the bike cranks but can't get the bike to start.

Not having enough I try to test this theory once more but this time by riding around in Bangalore city for a change with a bit more testing. So the next day early morning I went to start and the bike didn't start, Finally got the bike to start on 4th attempt or so and it finally started, and I rode around a bit with @Xaos636 and putter around, and stopped for a cup of coffee within the city and give the bike about 30 minutes break and tried starting it up again and as expected the bike starts up in half a crank, then we repeat the test again but this time leave the bike off for 4 hours or so and tried again and yet again the bike starts up with half a crank.

Puttering around Bangalore with Xaos636 for some city testing

So finally I think now one pattern is clear, it's not just the battery, because between the old Varta (with a bulge on the battery case) and the brand new BS battery, the bike is getting more steady juice and we have ruled out the battery charging system because the bike ran approx 550 km and the volt on a cold battery is still 12.6 and has plenty of charge left. So that's also cleared up, so no need to change the RR or Stator coil just yet. But yeah the pattern has finally emerged, that is, cold start is an issue, takes about 3-4 attempts to get it going and once the bike is properly running temps the bike has no problem starting up till the engine is dead cold again which takes a good 7-8 hours(at the minimum) or so after being parked up.

So finally with all this clear info at hand, I rode the bike to Highlander.

Briefed Karthick on all the points and he also seemed to agree, that the starter motor is the first place to check, and possibly the one-way clutch too, since it is also very much part of the starting system of the bike. So I already had the rebuild kit for the starter motor with me which I gave him and I also had the clutch side case gasket which will need to be replaced in case he wanted to check the health of the one-way clutch.

Carbon brush kit (Part no: 4C8-81801-01-00)

Clutch side gasket (Part no: 14B-15461-00-00)

So I gave Karthick both these parts and I returned to Kerala. Oh btw, All this is from last week.

So finally yesterday night I got a set of photos from Karthick, and the problem is pretty much clear, the start motor armature is pretty burnt up and the carbon brush is partially stuck in place.

I'll try and take some better-quality pics once I have the old starter with me in person. These photos very just sent to me for situation update purposes.

This puts me in a tricky situation the starter right now is not refurbishable in this state since the armature is pretty burnt up so the rebuild kit I have in hand right now is of no use currently. Now I have to go and try to find a brand new Starter motor assembly for the bike. Hopefully, I'll be able to get one soon because until then the bike is very much out of commission. That's the latest on the R1, will keep this space updated as and when the news turns up.

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