Running hotter on 98

[MrMelon]

I filled up with a tank of mobil 98 last night for the first time, and the bike seems to be running quite a bit hotter since then. Normally the temp gauge shows 70-80 degrees, but last night it was showing 90 to slightly over 100 when I was sitting in traffic for a bit

Is this normal, or is something going to go bang pretty soon?

The bike seems to be running much better on 98 though.. When running on 96 it had a slight hesitation at around 10,500rpm, but it was pulling hard till 14k last night. *shrug*

I might book it in for a service to get everything checked out this week.. I've got no idea what kind of maintenance I need to do on the bike or what fluids etc need to be checked.

[Coldkiwi]

probably something to do with the woeful quality of Mobil's petrol if anything.

try a tank of nice clean Gull 97 and see if it still does it

[curious george]

For knowledge base stuff, www.rgv250.co.uk can be good, as well as the aprillia site. There is alot of opinion on 2-strokes (read-bollocks), but someone like (I think it is dave?) sounds like he knows what he's doing.
If there are enough of us here, do we know enough to stard our own K.B? Would that be wanted?haha.
Most people seem to want to run on 98. MIne goes OK on both.
I think for track days 98 worked better?

[MrMelon]

It was just low on coolant.. that's why it was running hot :O

I didn't realise you had to take one of the fairings off to top the coolant up.

[curious george]

Hahahaha The old bike needs coolant trick.....Catches a few people out*meep*
If you have just brought the bike, it may be prudent to change everything.
It wont cost much, but you will learn heaps about the bike.
Coolant, gearbox oil (dont use car stuff......) brake fluid, the oil used for combustion, air in the tyres.......
Note the colour of the stuff and you may have an idea about it's previous life.
For no particular reason I use Motul gearbox oil and brake fluid.

[MrMelon]

Gah it's dong it again!

My temperature when cruising around is getting to 90 degrees, and it went up to just over 100 while stuck in traffic for 5 mins at a roundabout.. It's been running at 60-70 degrees since I got it serviced and the coolant topped up, so I ripped the fairings off again last night to check, and the coolant's still full..

Anyone got any ideas what could be causing this?

Thermostat not opening or water pump not going maybe?

[750Y]

CK wrote: "try a tank of nice clean Gull 97 and see if it still does it"

it's also the only fuel which doesn't come through the filthy marsden point pipeline & the octane rating is around 99.

[MrMelon]

I'm in wellington so that's out of the question.

It's been running fine for a month or 2 on bp and mobil 98 now.. it's just the cooling system that i'm worried about.. probably should have started a new topic really.

If only I could read that japanese service manual i've got :O

[jrandom]

Originally posted by MrMelon
Gah it's dong it again!

*now* who thinks race rep two-strokes are cool, eh?

You want a nice GN250, you do. Won't get no nasty cooling problems on one-a them. Get rid of that nasty TZR before it causes you any more trouble. In fact, I'm feeling charitable today, so I'll take it myself without even charging you for shipping costs. And that's cutting me own throat.

(ahem)

[MrMelon]

Haha, biatch :P

I've done 5000kms on it since I got it without any serious problems, and the current engine has been 20,000km's since it was last rebuilt, so I spose I can start to expect a few troubles until I get the rings done or whatever :/

But anyway, why's it running hot!? (and no I'm not giving it away :P)

[merv]

Originally posted by MrMelon
Gah it's dong it again!

My temperature when cruising around is getting to 90 degrees, and it went up to just over 100 while stuck in traffic for 5 mins at a roundabout.. It's been running at 60-70 degrees since I got it serviced and the coolant topped up, so I ripped the fairings off again last night to check, and the coolant's still full..

Anyone got any ideas what could be causing this?

Thermostat not opening or water pump not going maybe?

Usually thermostats fail safe i.e. open, so generally engines run too cool then. Too hot while stuck in traffic - does that model have an electric fan and is it coming on like it should?

You talked of lack of fluid in an earlier post - it hasn't blown a gasket somewhere has it? I'm wondering if you are getting air into the system from the engine. If so it would keep doing that and each time you check it cold the water level will have dropped yet you say the level is OK now. Another sign of gasket failure is the overflow tank filling up if the system is being pressurised by the engine.

Temperature sender unit or gauge failure are another possibility and its not really frying at all, but this is less likely.

You just got to troubleshoot all these things.

[Jackrat]

OK,It,s a hell of a long time since I owned a two stroke BUT.
Clean your exhaust baffles.Cheak your plug gaps,see if a cooler spark plug is available,
I have a mate that got a manual sent from Italy for his Benelli.
You can guess what langage it was in.Hahahaha

[merv]

p.s. what I should have added too is you need to know what temperature the engine should be running at. Most of what I have owned don't have actual temp numbers on the gauge but I know that with a pressurised system, like up to 13 psi, mostly they would have thermostats that open around 80 - 85 degrees, normal temp would be about 90. They can run easily to 100 and up to about 110 - 115 is when they are said to be hot and 120 is frying i.e. boiling.

I haven't owned a watercooled 2 stroke so can't really comment on whether 90 is OK for that or not but as I said above you need to find out what the correct temp should be. When it was running 60 - 70 you may have had a stuck thermsostat as that is really cool for most engines.

[MrMelon]

There was a lack of fluid earlier on, but I think that must've been because the previous owner just never checked or topped up the coolant. I got that sorted a few months ago.

The red on the temperature gauge is at about 120 degrees, and it's never really got anywhere near that. There's no fan on the radiator, so I spose it's understandable that it would heat up when there's no air passing through, and it gets back to 90 degrees fairly quickly when I get up to 50km/h+ again. From what I could see in the manual, the thermostat is set to open at about 67 degrees.

I took the cans off last night because one of them's rattling like a bitch, but they seemed fine apart from that.

If the overflow tank was filling up, wouldn't the level of coolant be lower once the bike had cooled down again?

[jrandom]

Originally posted by MrMelon
The red on the temperature gauge is at about 120 degrees, and it's never really got anywhere near that. There's no fan on the radiator, so I spose it's understandable that it would heat up when there's no air passing through

Um. Well, then, I don't want to be flippant, but what precisely are you worrying about?

If you *do* really want data on expected operating temperatures (and that would be understandable given that you want your baby in tiptop shape and all) why not just find a good two-stroke mechanic around town, have a chat and possibly (le horreur!) pay him for an hour's work to check the bike over...?

Or bribe a Japanese mate to translate the shop manual for you