Monday, 22 August 2011

Yamaha YZF R1 won't start after resting it overnight on rear wheel stand

So, I was working on my R1 last night, and left the sportbike overnight on the rear wheel stand. This morning the bike wouldn't start. More to the point: the starter did not have the power to crank the engine. I feel that there is so much compression in the R1 engine that scarcity of oil in the usual places make the crankshaft unturnable. I think  from being on the rear wheel stand, somehow the oil got distributed front wise and somewhat leaner to the rear of the engine, since the noise is now pointed down. I tried putting the R1 on 6th gear and push it to start, but I don't know about you, each time I tried that, it proved futile, the rear wheel would always lock after releasing the throttle. After pushing the R1 back in my house, suddenly the engine turned over again and started. Wow!
Maybe it's also time to change the battery. Maybe you are not allowed to just have one wheel stand.

Monday, 8 August 2011

Most probably solved the Yamaha R1 overheating problem

Here you can see the thermostat opening where it should, at 160F (70C)

For the past two weeks my Yamaha R1 was overheating. I was getting frustrated because I didn't know what it could be, and what makes it extra annoying is that the Yamaha R1 is my daily ride and parts are readily available, everything needs to be ordered.
I was pondering and was convinced the culprit was the radiator cap. Luckily for me, I also have a Kawasaki laying around and the cap is the same size and also 1.1 bar (16 psi). I thought that solved my problem (it looked good cause I refilled my radiator) but that didn't last long. My temperature kept rising up to about 210F, then I have to make traffic stops where it goes to 220 then 230, getting scary, but when I drove again, ok it backed off a bit to 210, but still is way to high.
I thought it had something to do with the fresh oil I did earlier on. I could not see a leak anywhere but somehow my radiator always gets empty. I thought I had an issue with the thermostat, you can easily see I was getting frustrated.
Tonight I decided to check the thermostat. First I checked the Yamaha R1 service manual to find where the thermostat is located, funnily enough, it's under the gas tank. I took out the thermostat and tested it in the kitchen with a thermometer in a small pot of water, stirring while it gets warmer. It supposed to open at 70c (158F) which it actually did, slowly. And slightly more at 170F.
The thing is, you see it opening, but you have no idea how much open is good enough. Anyway, I decided not to install the thermostat back in, since I ride in a hot climate with daily temps of 90F. But after doing all this, putting everything nicely together. I found was the overheating issue was....... Can you guess? On the road I filled with tap water, this time home, I put coolant in the expansion tank, and there immediately I could see there was a crack in the reservoir where the green coolant came out. Hard to see with regular water I guess. Earlier I looked at the tank, put thought I was scratches, but no, these where through and through cracks!!!
Okay, it's 12:45 am, how am I gonna solve this? After some cursing trying to get the reservoir out (I didn't want to take the exhaust split pipe out just to get that out) I had the reservoir somehow slanted to access the crack better. I found some JB Weld laying around. I roughned the surface around the cracks of the reservoir, cleaned with paint thinner, mixed the JB Weld, and smeared it all around that surface covering the crack. Now I'm going to sleep, and when I wake up, hopefully the JB Weld did its job, so I can mount everything back, fill the radiator and hopefully this time it solved my problem!!!!
So, it's not the radiator cap, not the thermostat, not the radiator, not the waterpump, but a tiny haircrack in the expansion tank!!!

update: you know..... later on, I also found that my radiator hose on the left front of the bike (near the oil filter had a small leak), this happened from the time I replaced my oil filter and had a hard time with it. I just cut the hose shorter, and now everything is super!