Temp gauge starts to rise........ unless

LotusSevenMan · Post by **LotusSevenMan** » Sun Jun 29, 2008 12:57 pm

you give it a handful then the needle drops like a stone. Back off the revs and it starts to rise again. Dodgy gauge/sender/loom??????
Battery is fully charged off bike BTW.

Ta in advance
LSM

alanw · Post by **alanw** » Sun Jun 29, 2008 1:11 pm

Thermostat stuck open / not there

Alan.

ScottaKR · Post by **ScottaKR** » Sun Jun 29, 2008 1:51 pm

Faulty water pump (corroded impeller), or a blockage/restriction in the water passages perhaps.

LotusSevenMan · Post by **LotusSevenMan** » Sun Jun 29, 2008 1:59 pm

Thanks guys! Neither sounds particularly inviting to work on. Hey ho. Let's have a look at the stat first then!!!
Cheers LSM

LotusSevenMan · Post by **LotusSevenMan** » Mon Jun 30, 2008 11:11 pm

Spoke with a TZR racer mate who said if the water appears to bubble from the rad cap when warm and removed then impellor pump likely to be working. It does.
More likely I feel that the stat has been removed for track day bike; pointers to the useage of this bike are:- all socket cap screws fitted all over the bike; wire locking holes for water drain at impellor and gearbox drain plug.
The lack of stat would explain the quick throttle blip creating a surge of water thereby cooling the sender unit immediately with the consequential drop at the gauge. I tried the simple fix of another gauge but identical readings.

the-elf · Post by **the-elf** » Mon Jun 30, 2008 11:26 pm

sounds like its been raced at some point. I run without a thermostate and I don't get a drop in temperature when bliping the throttle while warming the engine. I just get a nice steady rise in temp. Dose this only happen when you are warming the engine up or does it happen when your up to running temp?

LotusSevenMan · Post by **LotusSevenMan** » Mon Jun 30, 2008 11:36 pm

Raced? Maybe. Track days? More likely.

After ten/fifteen minutes of running with a mixture of idling and a few quick spins around my road/close (bike not taxed or MOT'd yet so not too far from home with it yet!!!!!!!!!!!).

the-elf · Post by **the-elf** » Mon Jun 30, 2008 11:58 pm

Drilled for lock wire sounds like being raced. Its mandatory for a race bike and not very common for any other reason.

If its happening when the engine is warm then it could be sludge in the water system blocking the water flow, at low revs? I don't think it is electrical.

LotusSevenMan · Post by **LotusSevenMan** » Tue Jul 01, 2008 12:20 am

Local 'LADZ' round here wire lock their brake retaining bolts " 'cos I then look like a racer mate" ha ha.

Well I'll have a look at the potential sludge 'problem' when I whip off the stat housing and possibly the impellor casing too. Can't really hurt to flush it all out well eh?
Thanks.
LSM

OK. Tuesday evening update.
Removed 'stat housing and found....................... a thermostat! Damn there goes theory 1. Removed, cleaned (although not dirty) and checked operation in hot water etc. Working fine.
Removed temp gauge sender wire that goes into the loom. Earthed it out and got full scale deflection. Removed sender and coupled back up to the loom wire. Now earthed the body out with a wire to the frame and checked gauge linearity with a lighter for heat on the sender. Operation just perfect. Put it all back together. Ran it all up to operating temp.
Same problem!!!
Removed water pump body. Impellor looks just fine. Start engine and it spins so ?
Where next????????????????
Anyone any more ideas please? [-o<

mgtkr1 · Post by **mgtkr1** » Tue Jul 01, 2008 8:21 pm

i reckon its the temp gauge playing up. there not the best and most people racing, ditch it for scitsu or similar. the rev counter is ok but the temp gauge is the opposite. it will do the job but not the most accurate. mine is also faulty so need to get a good replacement. should find one for about 50.00 or so.

garye345 · Post by **garye345** » Tue Jul 01, 2008 9:16 pm

try snapping the power valves!that might make it beehave

no seriously aint got a feckin clue me old,still carnt work out what you have done with tonights update but hey thats nowt new,what i can say is i seem to be building a decent selection of spares so if theres owt you want to replace to try i might be able to help out,just let me know

LotusSevenMan · Post by **LotusSevenMan** » Tue Jul 01, 2008 9:21 pm

MGTKR1

Have got three gauges here. Tried another before as stated and that was the same. Can't believe two would be wrong with EXACTLY the same symptoms etc. Haven't tried the third yet. Third time lucky perhaps ha ha.

Next guess is an air lock perhaps that allows the gauge to rise in the warm ish air and some water but a quick blip sees the water forced through like a tidal wave and it hits the sender. Pow; down it comes?????

The above from the clutching-at-straws-dept of bike mechanics.

Thanks Garye345. Nowt at this stage but who knows soon!!!!!!

the-elf · Post by **the-elf** » Tue Jul 01, 2008 10:11 pm

Just a thought, put a volt meter across the battery as you blip the throttle and see if there is an usually high voltage as you blip it. I think we have covered just about everything mechcanical I'm beginning to think there is somthing electrical but I can't think what ATM.

LotusSevenMan · Post by **LotusSevenMan** » Tue Jul 01, 2008 10:26 pm

Complaining neighbour so will try tomorrow!
Just removed the stat again to check the bleed hole is at the top as it should be according to the manual. Managed to drop it before I saw it (as slippery when wet.... oooh err) and which way it was fitted but will be able to fit it correctly with hole to the top tomorrow whatever.

Electrical? Might be an engine running thing? Fine as stated with it static and ignition on. Battery is charged but I guess that doesn't mean the genny is charging it when running (or overcharging?).
I have a 'spare' KR1 that runs here so can swop bits if required but as I last had it going a few months ago I can't remember what the gauge did. Sure it didn't 'dance' or I'd have had to have done something with it!!!!

LotusSevenMan · Post by **LotusSevenMan** » Wed Jul 02, 2008 9:23 am

Wednesday morning update!

Stat refitted correctly (in case it wasn't last time) with bleed hole uppermost. System refilled. Engine run until stat opened etc etc. All as normal temp gauge wise here as in wrong!!
Plugged in another gauge again. Same.
Checked voltages at battery. Idle 1,100rpm. 14.20volts. Revved to 4,000. voltage stable at about 13.8v

Changed voltage regulator for a good spare.
Same figures give or take 0.1V.

Seems lower voltage at revs than I would have expected as in thought the figures would have been the other way round to be honest but???