Loss of power / stall when bike warms up
Posted: Sat Feb 08, 2014 5:41 pm
I recently rescued a 1992 Seca II from my dad's garage. It had been sitting for a long time (10 years or more). I changed the oil and filter, installed a new battery and had all 4 carbs rebuilt. I also had new fork seals and tires installed, but that's beside the point. I rode it 200 miles from my dad's house to mine without issue. I've been using the bike daily for the last month, no problems. It has less then 20,000 miles.
Yesterday I was riding and downshifted twice instead of once, so when I released the clutch the engine over-revved and the back wheel locked up momentarily (less than 1 second). As far as riding was concerned it was not a big deal; the bike slowed down and the wheel started moving again.
A minute or two later, the bike started running roughly and began losing power. Then it quit on me. I started it back up, but needed the choke to keep an idle. Then I needed two clicks on the choke for it to idle. Then it simply would not idle. The starter turned the motor over, but it wouldn't take.
I let the bike sit overnight. Today I pulled off the tank and airbox, let everything air out, couldn't see anything obviously wrong. I put the bike back together and started it. It idled on the choke for about a minute, then idled normally without choke. Everything seemed fine.
I took the bike out for a test drive and the more it warmed up, the more it lost power. To make a long story short (too late) it eventually quit on me again and would not start. As before, the starter spins the motor just fine but it won't idle. This all happened in the course of about 5 minutes.
I'm thinking something let go inside the motor, maybe a piston ring. Ideas? Any help is greatly appreciated.
Yesterday I was riding and downshifted twice instead of once, so when I released the clutch the engine over-revved and the back wheel locked up momentarily (less than 1 second). As far as riding was concerned it was not a big deal; the bike slowed down and the wheel started moving again.
A minute or two later, the bike started running roughly and began losing power. Then it quit on me. I started it back up, but needed the choke to keep an idle. Then I needed two clicks on the choke for it to idle. Then it simply would not idle. The starter turned the motor over, but it wouldn't take.
I let the bike sit overnight. Today I pulled off the tank and airbox, let everything air out, couldn't see anything obviously wrong. I put the bike back together and started it. It idled on the choke for about a minute, then idled normally without choke. Everything seemed fine.
I took the bike out for a test drive and the more it warmed up, the more it lost power. To make a long story short (too late) it eventually quit on me again and would not start. As before, the starter spins the motor just fine but it won't idle. This all happened in the course of about 5 minutes.
I'm thinking something let go inside the motor, maybe a piston ring. Ideas? Any help is greatly appreciated.