Fixing a weird issue with my Yamaha R1: Coolant gushing out
This is a first, I have never seen this happen ever in my bike.
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The total ODO reading for the trip was around 342 km or so. Decided to take some rest as I had to ride back to Palakkad the very next day. The total ODO meter reading was around 39,920kms so I was beyond excited to start the ride back so the bike would have run 40,000kms by the time I hit Krishnagiri, but that’s where things took a turn for the worse. Worse? Why did I say worse? What was wrong in the first place? Well, let me take you back to the ride I took the week before, the ride to Kerala. While the ride from Bangalore to Walayar took me 4 hours flat to cover 400 km, the last 40 km was pure traffic and bad roads, but this is not new, it’s always been like that, but this time, when I finally rolled up to my house and switch the bike off, what do I see when I get off? Coolant is gushing out and spilling all over the engine cover and the origin of the leak from what I can only make out is behind the coolant overflow tank/reservoir, I quickly get my toolkit and open up the cover to get a better look and by that time the gushing has reduced to a slight drip and by the time I get enough clearance the leak/overflow has stopped.
This was weird, I have never had this happen before apart from once when I had a few drops of coolant drop through the overflow hose when the bike was just warmed up and switched off from a cold start, it never happened again though. Anyways, this was unusual and once the bike cooled down I realized the top rubber cap that seals the reservoir was not sealed and was loose, I know that the last time coolant was topped up the cap was sealed on properly, so something was causing the rubber cap to unseal itself and it’s pretty obvious it’s because of the pressure. Had a chat with Kartick and I just topped up the coolant after deciding that it was probably a clogged overflow drain that caused a lot of built-up pressure in the overflow container and finally it popped. I had decided that I’ll do a simple DIY fix at some point when I get time, but then Friday rolled over and plans were made for the ride, so I thought that I’d just ride back to Bangalore and take the bike to Kartick and we can just inspect to see if it’s a clogged drain hose or something else is the matter.
So this time I removed the overflow container plastic cover so that I could inspect the coolant level while riding safely rather than having to stop and check every time, the location of the container was very convenient for this being just above the shifter where your knee rests. So I start my ride to Bangalore early morning Saturday and have a quick break at Coimbatore bypass and the same thing happens, the rubber cap has been slightly raised and the container is physically full of coolant to the brim(this was such a big indicator of what was wrong, but I overlooked this that day, amateur hour).
I pressed the cap in place and carried on with my journey and had no other issues for the rest of the journey, then I reached the E-city flyover toll and I am waiting in line and the guy beside me pointed out that I was leaking coolant, I look down and sure enough the coolant is just flowing out of the reservoir, by this I was sure that I had lost quite a bit of coolant from the radiator as well because the reservoir only holds only a limited amount and over the 2 times I stopped where it was leaking I have lost more than that. So I quickly called Karthick and told him to be ready and outside the shop in 15 minutes as I would be reaching there so that he could see what was exactly happening irl. And sure enough, I pull up to Highlander after a few minutes of riding in traffic, and this time we see it happen in front of us the rubber cap pops up and a coolant is flowing out in a few glugs.
We discussed possible reasons and first and foremost is a clogged drain hose that was causing a build-up of pressure, other possibilities are huge air in the system or a thermostat or radiator cap issue.
Left the bike there for a couple of hours for it to cool down and let Kartick do his magic while I went to rest up for a few hours before the early morning ride tomorrow around evening time I got a call from Karthick and sure enough, it was a clogged overflow hose and now whenever the bike reached higher temps the coolant is being let out through the drain hose as intended and also do not now its just a few drops of coolant.
Now fast forward to the next day I am enjoying the ride to the core, we had quite a few breaks along the way and no leaks no drips everything was going well and then we reached our destination which after a couple of hairpins which were all taken in 1st and 2nd gear and the temps were above 108 degrees when I stopped at the top, this time too I just glance over at the reservoir to be sure what I saw had me stressed almost immediately, I can see again that the reservoir is filled up to the brim again but at the same time I can see the level dropping and this time the rubber cap is staying put and hasn’t popped but there is a steady flow of coolant being dumped to the ground through the overflow hose.
So clearly that means the issue has not been fixed, the clogged overflow hose was a separate issue that presented itself only because this other issue was happening, anyways I waited for the leak to die out and after about a minute it settled down and now the coolant level in the reservoir is well below the low level.
And I did not keep some spare coolant with me even when I had it ready because I thought that the issue was sorted. Anyway, there was no need to panic yet, I had ridden with an even lesser amount of coolant and the engine temps were very well within operating temps the radiator fans worked perfectly fine and the Samco hoses could withstand pressures well above what the stock rubber hoses can so now I just had to get the bike back home and I’d have time to check it out.
So we started the journey back and this time I was on the Blade, the ride to city limits went uneventful we stopped 2 times and noticed no coolant leak at all, but then while we were stuck in traffic moving at crawling speeds I could see that a few drops of coolant is falling out from the drain hose, this made me a bit worried because I did not want to lose anymore coolant and cause any damage to the engine, talked to Xaos636 as he was riding the R1, the temps were good and fans were working and no change in how the bike was behaving was noted so we pushed on.
But then towards the end of the ride is when I started to notice something new, I just made a quick stop to glance at the reservoir and I saw there were no leaks but the coolant was boiling over inside the container, this is a first, I have never seen this happen ever in my bike, all the previous episodes of coolant leaking was just simple plain overflow, there was no bubbling or boiling over happening, the only difference was this was when the ambient temp was also hot and coolant temp as showed in the guage was b/w 108-112 (the fan was running so it kept dropping).
I rode it straight to Highlander and we discussed options as I had to ride back to Kerala the next day no matter what. Karthick said not to worry just keep some spare coolant in hand and since my ride will be an early morning for the majority of the parts the ambient temps will be in check and at highway speeds the coolant temps will also be well within 70-80 degrees and only at the home stretch I’ll face higher temps and for that, I have enough spare coolant with me, and I can diagnose the issue from Cochin with Sanju or bring it back to Karthick when both of us have free time and find the actual issue. By now we had narrowed it down to a faulty thermostat or the radiator cap not sealing right.
So necessary preps were made and I fueled up the bike and was ready to make the trip back to Kerala, kept my spirits high as I was excited to hit the 40k milestone with the R1. And around 3.15 AM I started my ride back. There I am on the E-city flyover with ambient temps around 17 degrees and at cruising speeds in 6th gear I look at the console and I see something that just doesn’t feel right, the coolant temp is at 98 degrees, I immediately realized that this is not good, because, from all the years of riding the R1 in all possible conditions, I know that the temp given the current condition should not be more than 75 degrees, so I thought let me just glace at the reservoir and sure enough the coolant is bubbling/boiling over inside. This was frustrating because the 2 times I took the bike to Highlander and we did bench testing by making the bike temps go up it never boiled over it only dripped a few drops of coolant, and only the last couple of times on the road this had happened, and that too once when the outside conditions were too hot, but right now in the current condition there was no way this should have happened, so as I approached the end of the e-city flyover and pay the toll the boiling is still going on, right then and there I took the decision to cancel my ride home and took a U-turn and headed back to my flat, during this short ride back I experimented to see the severity of the problem, I get it to cruising speed in 6th gear and let go of the throttle and shift down and the temp starts to rise till 104 and stays put then I speed up a bit and it drops below 100 but it’s still high 90s when it should not be anything over 80. So I pulled back into my apartment parking and the coolant was still boiling over but no leaks.
I sent a voice note to Karthick about what happened and told him I am going to leave the bike with him and he can take his time and find the issue and sort it out because I am not willing to risk any internal damage to the engine, even though the bike never ran hot or had any power loss or even overheated once during all this, it was just the coolant pressure build up in the reservoir and then the bubbling over thing started, but I had enough and wanted to find and fix the issue.
Meanwhile, I had to be in Kerala the same day and Karthick was super busy as he was planning on taking a few days off and he had a huge number of bikes he had to finish so that his customers wouldn’t be affected (I have huge respect for his work ethics, part of why he is so famous in the South Indian biking community), so I did not pressure him to look into my bike rather I just decided to leave it with him and let him check it at his convenience because I was not planning on riding the bike anyways until the issue is sorted and next couple of weeks I would be super busy anyways.
But wait the bad day had just started, so now that I had a plan in place for what needed to be done with the R1 I still had to be in Kerala the same day anyway, while I was weighing my options I had pinged a few friends abt what happened and one of my friend offered me his spare bike to made the ride home, for some added context, my car was in Kerala so I did not have that option with me. After pondering about it for a while I took him up on the offer and went to pick up the bike, but by then I was already late, its a weekday, Monday for that matter and I was stuck in traffic to go get the bike, I finally reach and get the bike and start my journey around 9 am and as expected traffic is at its peak, somehow took me over an hour and 30 mins to cover 20 kms and I reach Silk board, my left hand is killing me after operating the clutch so much and I get a call from home saying not to come because it’s by the time I will reach it will be raining with heavy tunderstorms, I still wanted to go but realistically by the time I reach I would not be able to make it to the meeting that I had to have anyways, and I was already dead tired so considering eveything I called it quits, and had to reschedule my meeting to the next day which I didn’t want to do, but it had to be done. I reach back home and park the bike thinking I’ll just relax for a while and that’s when I realize I forgot to take my apartment keys while I stepped out to pick up my friend’s bike so now I am locked out of my apartment too, perfect! Back I go into traffic to my brother’s office to pick up his key and another hour and a half later I am finally inside my flat and just collapsed onto my bed and slept off for a good few hours.
But wait the silver lining is finally here, Fast forward 2 days and I get a call from Karthick that the issue has been found, and it was as we had discussed the radiator cap that caused all this drama, post the bubbling incident the radiator cap was so close to the brink of failure Karthick was able to replicate the issue easily on the bike lift itself which helped a lot in diagnosis. He managed to arrange a used spare radiator cap which is slightly off spec but in good condition and tested it on the bench and there was no coolant overflow or boiling over anymore. But we did not stop it at that time, Xaos636 came to the rescue again and he took on the task of doing actual road/traffic tests in both peak traffic hours and regular conditions and the bike passed with flying colors. There was no drop in coolant even after all the stress test and neither was there any boiling over of the coolant.
Now all I need to do is place an order for a brand new radiator cap and I can be at peace, but above all else I am just thankful that Karthick made time to work on my bike in between all his busy schedule with pre-Diwali rush (lots of bikes in for health check and ride preparedness works) and that the bike did not give up on me in any of these rides, I strongly bielieve that changing the radiator hoses in time was also a huge factor as to why I was not stranded on the road with a busted hose/radiator cap because if you consider the amount of pressure that was in the coolant system that got dumped into the reservoir the 9 year old hoses would have ruptured for sure, the Samco hoses are rated for much much higher pressure so it saved the bike so it speak. Anyway, I’ll have another post in the future in detail on what the repair work done was and what the stop-gap arrangement is. Since I am in Kerala now and the R1 is still in Bangalore, I don’t have enough photos or full info to give a proper explanation. Till then enjoy the next post where I show what my interim bike was for the ride back home.
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