Funkmans '91 XRV Odyssey

[funkman]

Rather then posting different subjects related to my XRV I've decided to set up a single post and update it. I think it's more convenient and will keep the forum tidy.
Anyway, now I had the bike for a few days and gathered a bunch of immediate problems which are a priority to sort.
1) Fuel consumption - 25mpg!
2) Slight popping on the downshift and when winding down the throttle, also throttle action is very jerky, winding down the throttle too quickly could send you flying over the bars.
Hopefully both of these problems are carb related so I shall investigate for any leaks, balance the carbs and clean the filter.
3) Neutral switch does not always come on when in neutral
4) Looks like the chain has seen far better days so will definitely have to change that
5) During my trip back I noticed some streaks of coolant on the aluminium sump guard so will have to investigate that.
6) Fit new tyres before "Deathwings" will send me to my doom.

So here I go my first mechanical experience with modern bikes.
Any suggestions, comments, advice appreciated.

[DaveS]

1) Fuel consumption - 25mpg!

Choke! Probably sticking on.

[funkman]

Balanced the carbs, checked the air boxes, sparkplugs, looked for any sign of leaks (none found), checked the choke cable, then took the bike for a 250 mile run. It's even worse - I'm getting just over 100 miles on a full tank and I keep it under 5000rpm.

It starts on the button and runs well, the only thing there are a few flat spots one at 5000rpm and one at 7000rpm and it doesn't want to idle evenly, jumps from 1000 to 1200 rpm constantly. But I can't think what else could it be?

The only thing I could think of was the Laser Pro Duro aftermarket exhaust, perhaps someone forgot to put richer needles or put too rich?
But could it realy reduce the mpg so dramaticaly?

[robelst]

Again what DaveS said: choke. You said you checked the cable, but did you check / cleaned the cable-splitter as well (sits somewhere half-way, usually filled with a mixture of rain-water, winter-salt and rust), the two individual cables that go from there to the carbs, and did you take the choke cables off from the carbs to check/clean/lubricate the plungers and springs in there?

If the exhaust would lean down the mixture, your bike would potentially run more economical, not less

BTW: Your exhaust fumes will probably eclipse the sun by now by being sort of.... black-BLACK - B L A C K: Put me in the cellar and feed me pins


There is a chance your spark plugs are being fouled beyond recovery. They are not expensive, just a bit of a pain to replace. Try a healthy blow-out first by giving it a mercyless ride.

[Dilbert]

The only thing I could think of was the Laser Pro Duro aftermarket exhaust, perhaps someone forgot to put richer needles or put too rich?
But could it realy reduce the mpg so dramaticaly?

Mine came with a MIG exhaust and looks like it had also been re-jetted (a bit rich).
sounds like you need to check the throttle action anyway and strip out the carbs to check for anything gummed up, shouldn't really affect the mpg as drastically as you say though and if the throttle butterfly was sticking then your revs would be high?
Dumb I know but have you checked to make sure the brakes aren't siezed on partialy? I found out when I took mine for it's MOT (thought it was a bit slow cornering!).
Has the bike been stood, like Robelst suggests if it has, lube everything up, squirt some Redex in the carbs and find a motorway, mine ran much better after I'd run it for a while, the last guy had it stood for about six months.

[funkman]

I'm quite sure that choke has nothing to do with it, I checked all the parts of it and lubricated them, it nice and free.

Yes I see what you mean about the exhaust. Oddly I have no smoke of any kind coming out of exhaust, which is a good thing but at least it would indicate the problem.

One other thing, when I reset the pilot screws they didn't seem to make much difference at all (if any).

[robelst]

One other thing, when I reset the pilot screws they didn't seem to make much difference at all (if any).

Pilot screws mainly affect idle and low rev fuelling.

If exhaust fumes and sparks plugs are normal (in other words, do not expose the signs of overly rich mixture) then either part of the fuel never reaches the combustion chamber (leak, for example rubbers between carb and cilinderheads?), leaking valves (fresh fuel pushed out through exhaust: do you smell petrol?: check compression!), or you're constantly riding at 110 mph so the bikes simply needs all the fuel it can get

If settings are too rich and you are sure choke is fine, it can be needle / jet wear or -size, or too high level in carb's float chamber.
Have fun!

[paultheold]

You do not need to rejet with the road legal can.

[funkman]

Is there an XRV parts book?
If so where can I get it?

[DaveS]

Is there an XRV parts book?
If so where can I get it?

Not strictly speaking. The closest we can get is the fiches in the tech data section of this site. You need to be logged on to see them. Still trying to get hold of the parts fiches.

Free unconditional love to anyone that can get hold of them.