Last run out on the NSR, I really thought I'd cured the occasional lack of go after about 1/2 hour running, with the corroded TPS terminal's.

NOPE.

Currently got all the electric's exposed, giving them all a thorough cleaning, waggle (wiggle?) and continuity check.

As yet nothing obvious.

With the 2 PGM connectors disconnected, and ignition on, some wire's show 12v, some show 5.5v and the one from the rev counter show's 6.5v does this sound right?

Yep I'm clutching at straw's again.

Help!

As previously mentioned, the bike generally run's fine, ocasionally , on a longer run out, the bike feel's really "draggy" and "sluggish", often getting worse the longer it's ridden, this is particularly so in the 5500 to 8500 rpm range.

Any Ideas

Thanx regard's Phil

Did you do a compression test before? What was the outcome? Refresh our collective memory please!

Andy.
NSR-WORLD.COM

Yup, Carried out a compression test.

Both cylinder's were within a couple of psi of 130, a check was made hot (when sluggish) and also when cold with little difference.

No knock's, rattles or misfires etc motor seem's sweet.

Seem's stock jetting, stock exhaust, some porting has been carried out, plug's a good colour, power valves working.

Good battery, charging system 13.5 to 14.9 (only at tickover)

I believe the PGM may have been recon'd at some point, took the base off for a peek, like new visually.....

Like I say this only happen's some time's, tend's to get worse the longer it's run, and tend's to be ok for quite a while after the temp gauge is up to temp @ 65' ish.

I'm baffled, still working on the idea of an intermittent electrical problem, problem seem's most exaggerated between 5500 and 8500 rpm.

Any idea's.

thanx, Regard's Phil

Hmm, so it runs strong for the most part, and powe seems good all around.

Have you checked fuel delivery? Drain the tank, take the petcock out, and check out the filter. replace, or remove (add an inline one if removed). Check that the breather whole in the top of the tank isn't plugged, etc...

Might have nothing to do with compression, or electronics.

Thanks,
_________________
Charles Gallant

Fuel delivery was my first port of call!!!

All the above have been checked and are good....

Did notice the other night tho that there appear's to be some "verdigri", bulid up on the fuel pipe. Perhaps flake's are coming off and partially blocking float valve.

Ok, I doubt it too but, hey I'm gettin' desperate!!!

Regard's Phil

I think this is a power valve problem. That's the rev range it works in, and if it's coked up it's struggling and dragging the power down.

When was your last de-coke? If it was ages ago, don't run the bike until you've done it - you may well ruin your PGM!
_________________
MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

Dave, Thanx for the reply.

The power valves are correctly adjusted, I have removed the cable's, lubed them (they werent too bad), the valve spindle turned smoothly and freely so at the time didn't bother removing/cleaning the components.

I have since had the exhaust's removed, there is (obviously) some carbon deposits visible on the valves and both part's of the valve (on each cylinder) have a slight sideway's movement with no 'stiction', so I am assuming that they are ok.

Piston deposit's look minimal from what I can see.

As yet I don't want to take the barrel's off, as this will invariably lead to more expense (piston's, ring's bore's...despite showing good compression).

Next step is to remove and inspect the carb's again but also give them a good blow out with the airline(just in case).

Then reassemble everything and try again (hoping I've disturbed something, for the better!!!).

The TPS was still giving inconsistant reading's, so I removed it soaked in WD40, removed the 3way connector, terminals were a bit grubby still, so soldered some new ones on for good measure.
The reading's seem more accurate!
The TPS wires are directly linked to the P/valve servo, so who know's.

(Not Me )

Here's hoping.

It's a good job I'm not counting the hour's I've spent working on this "hobby"......

Regard's Phil

Hey, look on the bright side... it's kept you out of the pub!
_________________
MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

A pub is warm, has a social atmosphere and I can get pi**ed, for much less than than the bike's are costing me!!!

Phil

'93 NSR MC21 (loses power)
'76 400/4 (bog's off throttle & 1 coil is knackered)
'01 TRX 850 (cough's and fart's when started cold - valve clearances need doing AGAIN....)

Oh.
_________________
MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

These niggly faults really piss me off! Phil, where are you? In the UK?

Maybe you are near enough to me or someone with a PGM and some other bits that could be swapped out to try and pin-point he fault.

Andy.
NSR-WORLD.COM

Andy,

I'm in Cleveland (N.York's),

Swapping part's is probably the next step, problem is it can take up to an hour or more for the problem to develop. If at all.

It's not like a misfire, where a prod on the kickstart and the problem either is or isn't cured...

I'll try and get a good run on it this w/end and see what it's like (kinda hoping the TPS may have been at fault, but I thought that once before!

Maybe I should strip the p/valves like Dave say's just to eliminate them. Do they need lubing before reassembly, if so with what?

Thanx regard's Phil

I even put a bid on ebay for that SP motor (in a moment of madness), must've been something in that lot to cure it!

Hmm... couldn't be much further away from me, I'm afraid!

Here's something you could try:

1. Disconnect the RC Valve servo motor from the wiring harness, and turn the pulley (by hand) so that the holes in the Valve pulleys align with the holes in the backplates. This will leave the bike rideable - not with full power, and not 100% flexible, but still rideable.

2. See how you get on with that. Then, if you still experience problems, remove the T.P.S. from the end of the spindle (being careful not to loose the little white adaptor between the T.P.S. and spindle!). Leave the T.P.S. attached to the wiring harness, but set it to approx 1/2, otherwise it can be a bitch to start!

Finally, try step 2 but with the RC Valve servo plugged back in to the harness.

Just a shot in the dark, but maybe the T.P.S. isn't working well, and is sending "spikes" to the PGM. Leaving the T.P.S. at a constant setting may show up something.

Andy.
NSR-WORLD.COM

Thanx for the tip's Andy.

I was thinking along the same line's of trying to Isolate it (something, anything )!

Also would it be possible to bypass the GPS by permenantly grounding the 3rd gear wire, while leaving the neutral wire connected, thereby allowing the neutral light to still operate, but once taken out of neutral the PGM will 'think' it's in third gear all of the time?

Just trying to build up an armoury of temporary "bodges" (hey I'm a farmer), just incase the p/valve and TPS trick's don't reveal anything.

To be continued.....

Regard's Phil

'If in doubt, Bodge It'

That's basically what our G.P.S. part of the wiresplice (or some of the delimiter boxes - Posh's box springs to mind, oo-er! - UK joke... nearly!!) does anyway!

Having the PGM "think" you are in 3rd when you are in 4th, 5th, and 6th is a good thing for performance if you don't use an HRC delimiter. (It may make the bike feel a little "different" in 1st and 2nd if the G.P.S. is permanently wired to 3rd.)

Andy.
NSR-WORLD.COM