people's average tempature

Hi peep's I've been building my piggio nrg engine recently and has come together well I've got an malossi mhr rep 70 with c 16 exhaust been on a few test rides getting the jetting sorted and just want to know what everyone elses bike. Average tempatures are as mine stays around the 70 c mark what's dangerously hot and can anyone tell me rufly the right temp thanks.

 

Thats nowhere near too hot. Also did you bleed the system?

 

soz didnt mean is mine dangerously hot wanted to know what is to hot for a alloy 70s kit and whats about average temp

 

above 90 odd is a bit too warm, its the same for all motors really, my camaro touches the overheat range at about 120, but the thermostat kicks in about 95 degrees

 

as above mine runs around 85

 

The ideal engine temperature is around 70 degree's c!

 

guess mines running to hot

 

what's everyone else's run at

 

What are you guys using to take the temp? An infrared electronic thermometer?
Now you have me curious, I will check my engine temp during a longer ride.

 

temp guage.

 

Temp gauge, cheap air cooled China scoots don't have one. I will be using the hand held infra-red unit ;-)

 

wait, isnt your air cooled?

 

Yup, a cheap Chinese air cooled 150cc Tank Sports Urban Sporty.

 

yeah, ac bikes dont have temp guages, let me know what it runs at, will be intresting to find out

 

On my way back from work I got 101.5 :/

 

I like mine (liquid) to run at 55. Metrakit recommends 50-60. My Malossi likes 60. If I ever saw 90° I would be turning it off and looking for the problem. Air cooled cast iron kits run a bit hotter - but not liquid kits ! Either upjet or find out where the bubble is in the cooling system. Just MHO......

 

Yeah I've got just water in it as well I'll put the proper stuff in when I have time

 

'Roxes have two annoying habits which lead to high temperatures. My ovetto has the full 'Rox cooling system and has been run with the original 'Rox cylinder & head (albeit a little modified) so here's what happens;

The most frequent cause of trouble is the head and the head gasket. The head of the standard cylinder is just not thick enough to avoid distortion. I have had to resurface mine twice - and the deviation is quite something - of the order of 0.3 of a millimeter. The result of this is that it doesn't seal the top of the cylinder and the compression of the engine is forced into the cooling circuit. The water gets pumped around the system and the bubble ends up at the pump inlet where it essentially stops the liquid circulating.

You can test for this. When the engine gets hot, undo the bottom pipe clip at the pump, and with the engine ticking over - insert a thin screwdriver between the pump pipe and the rubber hose and force the thing open. If you've got a bubble in there then the hot liquid will come spurting out really hard. Keep it spurting until it goes down to a trickle - top up the coolant - and tighten up the clip on the pump again. You will see the temp fall like a stone.
One day, someone is going to make a decent after-market cylinder head for the original cylinder with a propper squitch band, more mass and better 'O' rings. This will improve everything (including power) and then we'll be getting somewhere. Until then......

The second problem has the same symptom - and it's due to the actual red rubber ' 5 in one' gasket in the head. This is a piece of shit and anyone riding a Rox or a Nitro will tell you that it has a life of about 5000 km before it fails - and then you get the air bubble.

So if you've got a rox, and it's getting hot, first try the pressure -release at the bottom pipe of the water pump (the inlet of the pump where the long pipe from the radiator goes in) - and if (when) the bubble comes back, it's time to replace the gasket and resurface the head.

I have not touched on the 'warm up valve' in the head because I've never used one. This vile piece of filth restricts coolant flow when the engine is cold - and I leave it to your imagination as to what happens when it starts going wrong. Lose it, plug the hole with a suitable bolt, and let your engine heat up a bit more when you start it. You can remove the part of the water circuit from the carb as well and fill the two little pipes in the top of the head with sealant/solder etc.

Be advised that if you have to really work the head to get it flat again, you will be removing quite a bit of alu from the head and this effectively reduces the volume of the combustion chamber at Top Dead Center. This is tantamount to increasing the compression ratio - which can be a good thing - depending on what you started with. It can also increase it too far and then you will find that the scooter accelerates better, but subsequently loses power at full speed and it gets hot. This is a sure sign that the compression ratio is too high and you need to compensate with a gasket under the cylinder to get things back to a reasonable level. I would say 'measure the squitch band before final assembly' but with the daft head on the rox, you can't as there isn't a flat squitch band ! Instead there's a ridiculous ridge which defies any attempt to measure anything. So it's trial and error. Or get a decent kit from Top Perf or Stage 6 or whatever.

Lastly - and you know what I'm going to say , when you work on heads/cylinders - use CAFF red sealant on all rings/gaskets. I have found that apart from actually sealing the engine, on the Rox/Nitro - the sealant stops the head chewing up the head gasket and it will last longer.

 

You have so much knowledge! Thanks for all that, I Always use red sealant. I'll try those tests and thanks again mate

 

There's no merit in it. It's just that I had a devil of a time making the thing behave before I found out what was going wrong ! It's a good idea to do the 'squirt' test every time you've had the coolant out of it and put it back. For a long time I had the pipes set up in such a way that a preformed kink in the long hose was arranged so that the kink was actually lower than the level of the pump at the front end of the scoot. This is because the kinks were designed for the Rox, not some goonhilly putting liquid kits on Ovettos . For some bizarre plumbing reason - every time you put liquid in the scoot (when, say, rebuilding the engine) you would always have to bleed the system at the pump because there would always be the bubble. Having a second radiator probably doesn't help either. But now the pipe is re-arranged - this problem has gone away.
One thing is certain - having a temp gauge is essential !
I could write an entire novel on how to cram two radiators into an Ovetto - but it wouldn't be interesting reading.....
Do the squirt test when the engine is good and got and on tickover. Good luck -