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cht gauge

Posted: Thu Nov 05, 2020 7:40 pm
by rainbowrunner
Hi, could i ask best place to get a temp gauge, the LED type. seen a few on ebay for £43.50 but not sure if there ok for lambrettas, I,ve got the bracket for mounting it on light switch housing just need the bloody gauge now :D

Re: cht gauge

Posted: Thu Nov 05, 2020 8:42 pm
by Norrie Bodge
rainbowrunner wrote: Thu Nov 05, 2020 7:40 pm Hi, could i ask best place to get a temp gauge, the LED type. seen a few on ebay for £43.50 but not sure if there ok for lambrettas, I,ve got the bracket for mounting it on light switch housing just need the bloody gauge now :D
CHT Gauges

https://www.trailtechproducts.co.uk/aca ... aTTO_20CHT

Re: cht gauge

Posted: Thu Nov 05, 2020 10:16 pm
by rainbowrunner
thanks for the link Norrie

Re: cht gauge

Posted: Sat Nov 07, 2020 12:05 am
by zugbug
In case it helps anyone, I mounted two of mine with a small 'L' bracket from the leg shield trim cap. I also added my low fuel LED light and route the cables neatly down the gap. Works great and its nicely out of the way as I didn't want them on the handlebars.

Image

Re: cht gauge

Posted: Sat Nov 07, 2020 7:48 pm
by rainbowrunner
Hi zugbug, were did you order your cht gauge from and did you have to order the sensor wire seperate ? looks good what youv done.

Re: cht gauge

Posted: Sat Nov 07, 2020 9:49 pm
by zugbug
rainbowrunner wrote: Sat Nov 07, 2020 7:48 pm Hi zugbug, were did you order your cht gauge from and did you have to order the sensor wire seperate ? looks good what youv done.
Hi Rainbowrunner, I bought mine through Service Racing on ebay, Clive was super helpful and told me the CHT cable was 75cm from the packet, which was not long enough for my series 2 Lambretta.
https://www.ebay.co.uk/str/serviceracing

There were two extension lengths available at the time, either the 60cm (24") or the 120cm (48"). I checked by measuring with a bit of string routing through the frame and went for the longer 120cm one as i was just a little short with the total combined length. I do have a small bundle of wire under the toolbox, but its not a lot and its a very thin and unobtrusive cable.

For the Rev counter/Hour meter I asked the same question and was told that the sensor wire is 170cm long. You need 5cm-ish to wrap around the spark plug lead so about 165cm really. No extension was needed for the rev counter.
Hope that helps!

Re: cht gauge

Posted: Sat Nov 07, 2020 10:31 pm
by rainbowrunner
cheers my friend, super helpful

Re: cht gauge

Posted: Mon Nov 23, 2020 2:42 am
by operonalan
What should the temperature be when running ..i. e what is normal range and what is too hot etc ? ...if running too hot what causes it ? Cheers

Re: cht gauge

Posted: Tue Nov 24, 2020 12:37 am
by paul d
The questions above have put a smile on my face and to be honest, have caused many sleepless nights for very many people including myself! Normal range for me is anything between 140c to 180c. My scoots aren't standard. 180ish when travelling slow up long hills, slow into a continuous headwind or chugging 4th in traffic or in company at slowish speeds. When it goes towards 190c or beyond I get worried. A very rare occurence. I've seen 220c on an alloy barrel and an iron barrel too now that I think of it. I think beyond 200c is danger zone but I've never seized to know for sure. If I can't stop it getting to 200c by running with choke or dropping a gear and spinning the fan quicker then I pull over, blip the engine with the choke on for a bit and pray that the temp drops. It always has except once. I just knocked off the engine. I'd lost all the head cowling screws and the cowl was held by the exhaust in no mans land. Reasons for running too hot? that's a large box of headaches. Jetting and timing are very important to get right along with a proper piston/cylinder/head set up. Crud free petrol tank with good fuel flow essential.

Re: cht gauge

Posted: Mon Dec 14, 2020 2:58 am
by operonalan
Do you have to modify cylinder head to accommodate the sensor under the spark plug ..so it sits flat under the plug ? Eg with the trail tech model or others