Runner temperature

Hi guys,

Back after a long time and done it again, a new project, anyway I have a new project runner sp 50 and was wondering what the ideal temperature should be?

Currently it sits right under the red marker.

 

Whoa thats sounds a little high. Mine on hot days 30C stays in not more than 5 marks from the coldest.

 

Interesting, it wasn't even 15C here today so what its like on a warmer day I've no idea.

 

Kind a strange really. On lower temps mine is running in not more than max 4. So drain it out and fill it again at least this is the easiest thing to check.

 

I guess you meant the coolant which is going to be my first thing to do, I am going to buy some new coolant shortly and flush the system see if this helps at all.

 

Coolant changed, not much of a difference at all, ideas?

 

HAve bleed it right? I mean get rid of the air inside. There is a little bolt(bleeder) on the top of the cylinder.

 

Yeah mate, followed the Haynes manual and did all as stated.

 

Quite strange really. Check the temp probe if its faulty. Most of the time while sock mine was running like below photo

After 70cc conversion it added 1 bar plus.

 

Maybe I should of mentioned that its an old shape.

It also has a bunch of parts, Pm 70s kit, polini variator, clutch, belt and some other bits and bats.

 

Whipped the head off today, checked thermostat which worked although I left the thermostat out to let the coolant flow constantly, still no improvement on the gauge and still sitting under the red marker after 20-30 minutes.

Any ideas?

What should I be replacing/checking next? temperature sender unit?

 

Engine off, ignition on, pull connector off sender unit, put it against head, gauge should go all the way up and off the scale. This tests the temp circuit through the loom and clocks.
Have you changed the water pump at all? Easy check on that, run engine, whilst still cold, take water bottle cap off and see if there is a jet of water coming out the small pipe on the neck of the bottle.

 

Wouldn't be a bad idea to put a new temp sensor in anyway, only small cost.

 

Hi Steve, thanks for the advice.

I have already tested the sender unit and it did as you stated.

About the water pump, I don't know a whole lot about it I have how ever felt the intake/return pipes and they are holding coolant ect, as thats the most I knew(lol). When the engine was rebuilt it did have a new belt for the pump, I will do as you said within the hour and get back to you.

 

Hi Steve,

Checked as you said, when I rev'd up the ped there was jets of water coming out the small pipe on the neck.

 

If the jet of water was constant then that confirms that the pump is working fine.
Change the sender unit first, could be giving a wrong reading, they are only a small cost and it's not a bad thing to do anyway.
But also, take the bike for a 5 mile run at normal road speeds, then check to make sure all the water pipes are scalding hot. You should be able to hold the water pipes, but not for long.
Then try and put your hand on the edges of the radiator.
Be careful though, because if it is hot enough it will burn.
If you can put your hand on the rad and keep it there, then it's more than likely it has a blockage in it.
I had this with a vx125 recently. Took it for a mad blast to get it boiling hot, got back to the garage and could still put my hand on the edges of the rad and keep it there. But this was the opposite to what you have going on. The vx just wasn't showing as hot at all, and even when I changed everything it was still running very cool.

 

Hi Steve,

Thanks for the advice again.

I've been trying to get hold of a sender unit all day might be out of luck until Monday now

But will get back to you as soon asap with the outcome.

 

I just got back from riding it a couple of miles so thought I'd feel the pipes and rad even though it wasn't boiling hot, anyhow the pipes was all hot(4 rad pipes, head and pump(?) pipe) and the rad sides was even hotter, close to burning-hot.

Thoughts?

Thanks.

 

see what the new sender unit does. could well be that that is the way that particular bike is running. although there is a product on the market called supercool or something like that, supposed to reduce the water temp quite well. mate of mine has it in his cosworth 4 x4.

 

Will do mate, its the first runner I've had and everyone I spoke to said the temp was way too high hence me trying to sort it lol.

Will also take a look into that coolant, thanks.