My EXUP Adventures
Posted: Tue Aug 15, 2006 7:37 pm
I have a 97 YZF1000 with around 14,000 miles on it and I thought I would pass on some recent events related to the EXUP system. I know this is a "well discussed" topic.
I started noticing this rattle and a few reads on this site had me pretty sure it was the EXUP. I was a little baffled since the bike only had about 10,000 miles on it at the time. I recently had the bike in the shop to have some oil seals replaced (front sprocket, shifter, etc - the dreaded kickstand oil footprint) and new chain and sprockets, so I asked the guy if he would look at the EXUP. He told me a few days later the collar and the valve itself needed to be replaced. I was looking at a few hundred dollars in parts that I just wasn't ready to spend.
We decided (on his advice) to remove the valve and see if I noticed a difference. I retained the parts. He fixed it up with a nut and bolt in the hole in the housing and simply removed the valve and related parts.
The first thing I noticed is how much LOUDER the bike was at idle and low rpm. I have a V&H SS2R can on the bike. I didn't notice much of a difference sound wise and higher rpms. Figures since the valve was no longer there closing up the exhaust at lower rpms.
I also noticed a HUGE difference in power at around 3000 rpm, there simply wasn't any. I would be riding around town and roll on the throttle and it would sort of stumble and finally get into some power. It really resulted in a downshift where one wasn't needed before. It was really a BIG difference. The bike also now had a very rough idle.
I decided to replace the EXUP and started looking around to order parts. I was messing with the old parts to see how it all went together and I'll be darned if I could detect any "play" between the collar and the valve, just and snug as could be. I decided to put the old parts back in and adjust everything according to the service book and see what happened. I did that and adjusted the cables and I'll be darned if that thing doesn't work like a champ. I have put a few hundred miles on since then with no rattle and the bike is running better than before.
So, why did I have the rattle? I have two theories. First, the cables were way out of adjustment, althought the mechanic said they were fine. Second, I think perhaps the valve was shaking side to side. There is a little spring in there between the washer and the pulley that is meant to keep it from doing that, but it is not much of a spring. I tool real care to make sure it was installed properly. Either way, the rattle is gone and I did do anything else to it than put it back together the way the book says. Go figure.
By the way, replacing those seal fixed the "oily kickstand footprint".
I started noticing this rattle and a few reads on this site had me pretty sure it was the EXUP. I was a little baffled since the bike only had about 10,000 miles on it at the time. I recently had the bike in the shop to have some oil seals replaced (front sprocket, shifter, etc - the dreaded kickstand oil footprint) and new chain and sprockets, so I asked the guy if he would look at the EXUP. He told me a few days later the collar and the valve itself needed to be replaced. I was looking at a few hundred dollars in parts that I just wasn't ready to spend.
We decided (on his advice) to remove the valve and see if I noticed a difference. I retained the parts. He fixed it up with a nut and bolt in the hole in the housing and simply removed the valve and related parts.
The first thing I noticed is how much LOUDER the bike was at idle and low rpm. I have a V&H SS2R can on the bike. I didn't notice much of a difference sound wise and higher rpms. Figures since the valve was no longer there closing up the exhaust at lower rpms.
I also noticed a HUGE difference in power at around 3000 rpm, there simply wasn't any. I would be riding around town and roll on the throttle and it would sort of stumble and finally get into some power. It really resulted in a downshift where one wasn't needed before. It was really a BIG difference. The bike also now had a very rough idle.
I decided to replace the EXUP and started looking around to order parts. I was messing with the old parts to see how it all went together and I'll be darned if I could detect any "play" between the collar and the valve, just and snug as could be. I decided to put the old parts back in and adjust everything according to the service book and see what happened. I did that and adjusted the cables and I'll be darned if that thing doesn't work like a champ. I have put a few hundred miles on since then with no rattle and the bike is running better than before.
So, why did I have the rattle? I have two theories. First, the cables were way out of adjustment, althought the mechanic said they were fine. Second, I think perhaps the valve was shaking side to side. There is a little spring in there between the washer and the pulley that is meant to keep it from doing that, but it is not much of a spring. I tool real care to make sure it was installed properly. Either way, the rattle is gone and I did do anything else to it than put it back together the way the book says. Go figure.
By the way, replacing those seal fixed the "oily kickstand footprint".