In Search Of...

[dm_gsxr]

The 'busa's been doing some weird surging over the past year. Nothing engine related as near as I can tell. The tach doesn't change as I keep the throttle at a static position.

I've been gradually getting parts and bring the bike back to long trip worthiness (got that trip in August coming). Also to try and identify where the surge is.

One thing was when I was on my way back from Alaska last year, I had to get a new chain. The shop put one one but at 111 links rather than 112 so it was right at the short end of the throw. The guy also said I needed a new sprocket but he didn't have one in stock.

Anyway, I ordered a replacement sprocket and chain and picked up a set of front brakes (four pads). I also bought some rear brakes but in changing the sprocket, I could see the rear pads were still in great shape.

There still seems to be a surge. Most obvious in fourth gear. But I didn't really feel it after getting back from Boulder (I went from Longmont, up to 66, over to 36, down to 119 and back to Longmont).

Still scratching my head over this.

But here's a pic of the new chain and sprocket



Carl

[Doron&Katie]

Maybe the fuel pump screen at the pickup in the tank? You know the '99s had a recall on those. G/L

[dm_gsxr]

Maybe the fuel pump screen at the pickup in the tank? You know the '99s had a recall on those. G/L

I didn't know that (this is an 02). I'll have to check it out. I'll have to pop over to the 'busa forums as well and see if there are any ideas there.

Thanks.

Carl

[TheStig]

Maybe the exhaust is clogged with parts from that dead animal on your seat?

[dm_gsxr]

Maybe the exhaust is clogged with parts from that dead animal on your seat?

With almost 90,000 miles, the seat has given up the ghost. I need to chase down another seat, maybe a stock one since it's worked well for me so far

Carl

[Gregger]

Have you looked at the chain? A loose chain can cause the bike to feel like it surges.

[dm_gsxr]

Have you looked at the chain? A loose chain can cause the bike to feel like it surges.

I replaced the chain yesterday, hence the picture I took it out for a ride afterwards. It seemed ok up until 4th gear and it was really having a problem. Once I got onto 66 and to 5th and 6th it seemed to be good. So it only seems to happen in 4th, or at least it's most obvious in 4th.

Carl

Edit: Oh and on the way back down from 6th to 4th it seemed to be gone. Could just be an artifact from the new chain getting loosened up.

[Devaclis]

Just looking at the picture, I have discovered the problem. It is the 'busa.



I had a similar problem on my Hawk but it was carbed. Turned out to be a stretched return spring on the throttle arm, on the carb. ODD issue for sure.

[MetaLord 9]

Clutch? Possibly loosing then regaining friction?

[dm_gsxr]

Clutch? Possibly loosing then regaining friction?

I replaced the friction plates, I want to say last year, a month or two before going to Alaska. The metal plates and springs were still in spec so I didn't replace them.

Carl

[Nick_Ninja]

My push rod was worn a few mm and caused the clutch to slip. All other parts had been replaced.

[dm_gsxr]

I need to replace the front and rear tire and redo the suspension since I have new pipes (weight change). Just for the last few things to change.

And the engine sound doesn't change while it's surging, same as the tach. I hold it at a constant speed and watch the tach and listen to the engine. No visible/audible change in either. It's the reason I changed the sprocket and chain in the first place.

Carl

[dm_gsxr]

My push rod was worn a few mm and caused the clutch to slip. All other parts had been replaced.

Hmm, why would that cause it to slip? The push rod releases pressure on the clutch plates so you can shift. Having a shorter one would have meant that it would take more pressure at the clutch lever to relieve enough pressure to shift.

I've rebuilt the clutch system from the lever and master cylinder, the hose, and slave cylinder. The push rod was nice and shiny. I use chain wax so it gets a regular coating.

Carl