A Transmission Conundrum

So, I posted about the original problem in this thread, but the problem has not yet been fixed.

Here are all the symptoms (related or not, I don't know) that I have seen. The bike is a '98 VFR800 with about 23k miles on it.

The main problem is that the clutch is slipping, badly. If I am stopped, it will eventually get to the point that I have no power whatsoever, and can let the clutch lever out all the way with no response from the bike. This starts to happen when I am riding in traffic, mostly, keeping my speed below 40 kph or so.

The other thing I have noticed is that the bike gets VERY hot while this is going on. I've had oil temps up to 240 F, which actually made the machine uncomfortable to sit on. For this reason, I tried just letting the bike sit and cool down before attempting to go anywhere. This helps, and lets me get moving enough to get to a freeway, where I can pick up some speed, and cool the bike off the rest of the way. After this, the clutch ceases to slip.

The air temp reading when it cut out on me today was also very high, around 140 F. It was not that hot outside, nor was the road even that hot. The ambient temp was maybe 70 F.

Here is what I have done to attempt to fix the problem already:

1) Took it to the Honda Dealer. They flushed the hydraulic clutch system and re-filled it. I assume they bled it correctly, but when it kept happening, I...

2)Bled the clutch hydraulics myself. If there is anything other than fluid in there, I would be very, very surprised. I bled almost a full liter of DOT 4 through the system, so I am convinced it is all set.

3)Added coolant. I thought the problem might be related to not having enough cooling, so I checked the coolant level and added more (mixed at a 50% ratio with distilled water, of course).

Unless one of you brilliant gearheads can come up with something new, my next step is to take it back to the Honda dealer and have them overhaul the transmission. I would do it myself, but I don't really have the space, the tools, or the experience. Please, please come up with something to save me some money and the trouble of explaining in my terrible Italian everything that I just wrote here to some poor mechanic from Honda.

~Jack

 

Why would you have them over haul the trans?? That's not your problem. You burnt the clutch up. Once it starts to slip and you keep driving it that way the more it slips, heats up and glazes/hardens the frictions and warps the steel plate. No matter what the original problem was (bad clutch slave cylinder) you have smoked the clutch. You need new frictions and steels plus possibly springs for the pressure plate.

p.s. If your dealer couldn't figure that out, then run away Forest.......................................

 

I am with Grey on this, clutch sounds like a simple fix. The temps dont sound good but not oot of the norm for the gen 5 bikes I have seen in summer time traffic.

 

You can also check the wire on the temperature sensor on the radiator. Mine became dislodged while waxing my bike, and my temp spiked (as the fan didn't 'know' to come on)...

 

Two things to check.

1. Remove the clutch slave cylinder from the left chain guard cover. Remember to clamp it or the piston will come out. You will find a metal rod that goes through the engine that is the out h actuation rod. It often gets dirty with chain lube & road grit. So pull it all the way out & check it moves freely. Clean the rod & hole if required, then reassemble.

2. The VFR often suffers from clutch slip when the clutch springs exceed there wear limit, i.e. they get to short.
You can access the by removing the right sided airing panel & the right side engine cover. This can be done without dropping the oil by working with the bike on the side stand. You will need a new clutch cover gasket & be aware that there are a couple of locating dowels & gear cog that can fall out. So put some lean paper down to catch them & any oil drips. Put the bike in gear, press the rear brake & undo the 5 clutch spring bolts. You can measure the free length & whilst its apart have a look at the first couple of clutch plates, just put them back in the right order. Fit new &/or heavy duty springs & reassemble.