Front Sprocket play on vfr700fII

Well... This is where I am at. I have an 87' vfr700fII with 56,000 miles in what I would call good condition for the year. Near the start of this season, I decided it was time to replace my chain as it was making quite a bit of noise. For whatever reason I decided to not replace the sprockets as well (stupid, I know). I quickly noticed a whirring noise under load that seemed to be coming from the front sprocket area, I then replaced both sprockets within 100 miles of the new chain. The noise persisted. I read a few forums of similar noises and it seemed that it could just be normal chain noise that I was being sensitive about, but it just got worse and worse. About 800 - 1000 miles later I decided to pull it all apart and figure out what the issue was. I noticed quite a bit of play in my properly torqued front sprocket. Upon further investigation the splines of my output shaft seem to have notches on them where the sprocket would stop mating with the shaft. This leads me to believe that my output shaft is worn. I am hoping to have any input whether this notch is normal, if the output shaft is easy (relatively) to replace, or if its just easiest to source a new engine. I can post photos/videos of the play if that helps anyone understand what I am dealing with. Any input helps is greatly appreciated.

 

Notch is not normal.

That is a split-the-cases scenario.

Good news: Gear Driven Cams makes the job easier

Bad news: It's still a hard (more tedious) job that will undoubtedly bring to light other issues. Aka: Snowball effect. While-you're-there syndrome. Can-o-worms.

Depending on how bad, you can likely live with it while you decide if it's worth it and what path to possibly take.

 

What does the job entail? I am fairly confident in my mechanic skills, but would like to avoid getting too far into the transmission if possible. I am willing to sink a few hundred bucks into the project but am a student so I don't have unlimited funds or time. The play is pretty bad. I have play up and down, in and out, and rotationally.

 

The job entails splitting the cases. Which does not necessarily mean removing the heads on some bikes. I was able to split the cases on one of my VF500F without removing the heads.

That IS the transmission. It is made up of the Main Shaft and the Counter Shaft, and the associated gears. The shift forks move the gears on the shafts.

A good shaft and sprocket will have some play, but no notches obviously. That's why it might not be as critical as it seems for now.

 

Okay, How much play would you define as too much to continue running the bike?

 

just a crazy suggestion, a wobbly front sprockets might get welded to the shaft as a temporary fix

 

NOTHING temporary about that. Run it or fix it. The next owner will put a curse on you and your family if you weld it.

Or I will... Double Double Toil and Trouble...

 

consider that a new sprocket welded in place would likely be good for 15k miles with no worries. see what happens. the shaft can be replaced later.

 

Or can be replaced now. OR can be replaced in 15k miles when this chain and sprockets is used up. And somebody doesn't have to FUCKING grind off a sprocket from the shaft to just disassemble a crankcase.

 

wait a sec, r u sure the shaft coudnt be removed with sprocket in place ?

 

I don't need to be sure. Any real mechanic would never do it. But the breaker might find out after buying one of these/your machines.

And then put a curse on you and your family.

 

Cap, keep up the good fight. 100% on the mark. The last thing this threads needs, is my $0.02

 

I will not be welding the sprocket on. That would destroy the hardness of the shaft and likely cause issues greater than some play on the sprocket. I read on another forum that I could put an additional washer on the sprocket bolt to reduce the play. Would love to hear what you guys think about that idea. As I don't have a space I can comfortably split the case.

 

Installing a washer isn't going to help against the lateral wear you report. People that install washers likely think they are helping a problem that doesn't exist. A good sprocket and shaft has some "play" when they are restrained by a singular bolt and stock washer on the shaft end.



I never liked it and prefer the 2 bolt plate that is clocked in a groove. But I accepted that it was how it was designed for that application and have never had a problem because of inspection and maintenance.

Run it or fix it. Personally I would consider my options over the life of the current parts. You wear ear plugs, right?

And post some pics of the notch you are reporting maybe.

 

Here is the photo of that notch.

I added anti-seize to the splines to reduce corrosion and add lubrication and put the bike back together.

Let me know if this is an aggressive amount of wear that would lead to the bike being unsafe. I really appreciate the help.

 

Photo no worky

 

The forum doesn't seem to like any photo-sharing programs. Never seem to have a problem with uploading a photo directly from my desktop/ laptop/ tablet using the "Upload a File" button.