Vespa PX temp gauge

[dannyspry]

Modders,

I have just purchased the polini air filter set and now I'm looking at getting a temp gauge just to slim the risk of a seizure. Does anyone recommend a analog version temp gauge? I'm not into the digital versions out there and can't seem to find one to suit the PX. Currently running a dr 180 kit with 24 carb.

[dannyspry]

Any suggestions to a temp gauge guys?
Cheers

[sime66]

Danny, I didn’t reply before because you asked for recommendations and I have nothing to recommend; I looked at lots gauge of options, as well as SIP speedo which I didn’t like, but I never found anything dial/analogue good enough to temp me either.
Aviation and marine gauges came closest - you have to keep in mind the most auto ones aren’t waterproof because they’re for dashboards, not bikes/scoots.
Ensuring you have a high enough temp range on the gauge is crucial too. Some American sites show a good range one if you want to spend US$60 then find the rest of the kit; like this VDO (there’s a 600°F one too, if you live in a cave):

www.ebay.com/itm/VDO-Viewline-Cylinder-Head-Temperature-Gauge-52mm-2-60-200C-Black-A2C59514156-/141778247178

The last reason I gave up on round gauges (which I agree would look good) is that the obvious place would be the top of the toolbox, which I didn’t want to do because it isn’t a very practical place to be looking down at a gauge, and I didn’t want even more wires, or the gauge body, hanging down in my lavishly-tooled toolbox either. I also read whilst looking around recently, that the dial ones respond slower.
Those little Trail Tech ones are what I went for after looking around and considering all options, and I’m happy with them right up in my eyeline above my speedo. They are not illuminated though, and the ‘5 yr’ battery life, and changing the battery, are things I’ve yet to deal with.
There’s good discussions and examples on Modern Vespa as well as several on this forum if you use the search facility. Type in CHT gauges in Google and you’ll see the sort of round ones, but I think you’ll find temp range and cost will soon turn you off the idea, unless you take pot-luck with something Chinese.
What’s that online (Indian?) gadget site you mentioned a while back, H?

[dannyspry]

Thanks for getting back sime.
I did think about the aviation type but didn't take in to consideration the possibility of water ingress.
I looked in to purchasing the sip speedo and this might have to be the route I take.
Has the digital standalone worked for you? Has it been worth the effort?
Thanks

[hully1]

on this subject does anybody know the max temps before a heat seizure will occur?

[sime66]

Don’t forget CHT is only part of the story; there’s EGT too, and I haven’t quite got my head round that yet, but a safe CHT isn’t necessarily a safe EGT; they change differently for different reasons; I found an interesting page last night, which I'll post if I can find it again.
Having said that disclaimer, on the American sites they seem to be saying up to 400°F, which is 200°C, BUT I think on here we’ve generally agreed that 150°C is the upper safe limit, though I’ve sort of revised that in my case to 160°C. There ain’t a number at which point it goes bang, or a number that's correct for every scooter.

Re: earlier question, Danny. I like the TTO digital CHT. I could do you a list of pros and cons, but your list would differ for your needs and taste; it’s a bigger readout than the SIP speedo, the SIP speedo is more complex, lots can (and does) go wrong with them, and I think the PX one looks a bit shabby though I like the P one. There is no real effort in fitting it; I chose to run it through the tunnel and up into my headset because it’s neat, but not necessary. I have some doubts about whether I’ll be able to change the ‘non-replaceable’ battery, though some have tried and report success with it. If not, it’s a new unit, but not the new lead or sensor; if that’s five years time I’ll be happy enough. I’ve just got the matching rev counter too, which I wouldn’t have done if I thought they were poor quality. The sensor ring is sturdier than the SIP ones too. I could go on…….
I weighed it all up and I’m very glad I got it, and so far pleased with how it performs; it’s useful and a bit of a safety net. None of the options available is perfect, but I thought it was important to have something.


Here:

modernvespa.com/forum/topic48786?sid=0e46d41e0c752898b2c00c25fc3192d5



This (as a starting point to understanding EGT vs CHT):

[dannyspry]

Cheers Sime, can't believe there isn't a suitable analog version out there.
I'll have a think about it, I just thought it would be handy like you say.
I've bolted some extra bits on to give the little engine more go and at least with the sensor you can keep an eye on what's important.