Overheating Ec300

[normanator27]

Hi,
my 08 model is overheating when its quite hot. It overheated on the weekend just gone when it was 32degrees and quite humid. it was pretty muddy so the pace wasnt that quick but i wasnt flogging the bike by any means. Its also overheated previously on similarly hot day or maybe a little warmer but dry day, albeit at a gentle pace as i was alone and doing a little exploring. Its all pretty good until after around 30-60 minutes then after hitting the pipe a bit, it starts to surge for revs a little (sort of sounded like a rotary engine) when the bike isnt moving. It also leaks a bit of what I can only presume is oil from where the spark plug screws in when its overheating.Ive been reading a few posts about dodgy radiator caps so i'll have to try and get my hands on another one and see if thats it. If anyone could give me a clue to other things I could be checking that would be great. Thanks.

 

[gassergrant]

Check the water pump is working mate. Pop a hose of and run a garden hose through to see if there's any blockages. Or if it has a thermostat check that's working
I had a leak from the plug it's been over tightened and compressed the washer to much

 

[Simmo737]

Water pump failure, cap not holding pressure, leak (pinhole, rad pressed edges etc or into cases) and coolant loss, "use by date" on coolant ( if it's boiled, change can help).

 

[normanator27]

Water pump failure, cap not holding pressure, leak (pinhole, rad pressed edges etc or into cases) and coolant loss, "use by date" on coolant ( if it's boiled, change can help).

I dont think its leaking as the fluid level never went down. The coolant was changed when i did the piston and rings about 40 hours riding ago, although ive changed that again anyway. next step i'm going to check the thermostat and impeller as the bike has done about 120 hours and im assuming the impeller is the original one. i'll also try the garden hose thing the last bloke suggested as well.

thanks for the tips gents ive got a starting point.

 

[gassergrant]

take the water pump cover of and kick it over to see if it move and maybe try and hold it to see if it spins or not.
I ran my cr with a broken pump it worked fine in the winter and did not seize or boil over I think I was bloody lucky tbh well until it seized up due to the bridge not being re leaved

 

[webmaster]

If the bike has been overheating and it has a non-metallic water pump impeller - remove the water pump cover and check it. it is probably "toast".

if you have a non metallic impeller - even if the impeller looks good - replace with an upgraded machined alloy impeller - it is more efficient and more durable.

Also check for anything that might make it run lean - check for air leaks at carb insulator and clean carb to ensure pilot is clear. Switch from oem jetting specs to different needle and richer pilot if you haven't already.

jeff

 

[Lincolnlock]

I'll bet the bike is running lean. With it being 32 degrees you'll probably need to turn the air screw in a bit.

 

[normanator27]

I'm running a 42 pilot, 175 main with a N3EG needle on the second from top clip position. edit: the air screw is out 1.5 turns. the plug colour is good with scope to run a little leaner according to a mechanic friend. Still i'll check all the things youre recommending. What are youre thoughts on my jetting specs?

 

[Caravan Monster]

If not coolant or jetting related, it may be worth checking the flywheel side main bearing. Remove the plastic flywheel cover, grasp the flywheel firmly and check there is no up / down movement. When the main seal starts to go, it causes lean / erratic running and overheating. Hopefully not this, but only takes a few minutes to check.

 

[Simmo737]

I'll bet the bike is running lean. With it being 32 degrees you'll probably need to turn the air screw in a bit.

32 degrees c not f, about 90f, if anything it will be richer

 

[Jakobi]

I'll bet the bike is running lean. With it being 32 degrees you'll probably need to turn the air screw in a bit.

Celcius!

32 degrees c not f, about 90f, if anything it will be richer

Beat me to it

I'd start with some fresh coolant, flush the lines out, and inspect the impellor. Quick check for airleaks won't hurt either. Maybe slide the stator cover off and see if any oil weepage in the area.

 

[normanator27]

Celcius!



Beat me to it

I'd start with some fresh coolant, flush the lines out, and inspect the impellor. Quick check for airleaks won't hurt either. Maybe slide the stator cover off and see if any oil weepage in the area.

Hi Jake, its the same gasgas with all the troubles from dbw. Its the one with your N3EG (which I bought from you) in it. It has fresh coolant although i'm going to drain it again to check the impellor, when you say flush the lines out do you mean leaving the drain screw out and running the hose in the top of the radiator for a minute or 2? As far as the stator cover goes I had it off about 5-10 riding hours ago when I had the stator out to be checked, and there was no oil in there then, and it was showing the same symptoms back the with the surging revs at that time so really nothing has changed in that time. this bike is not going to beat me!!

 

[normanator27]

Ok then. Bearing in mind ive never done any of this stuff before so my opinions are that of a novice. So, Ive drained the radiators and left the drain screw out and run some water through and it seems to flow ok. I took the water pump cover off and the impeller although looking a little discoloured for plastic doesnt appear to be damaged. Somebody mentioned previously turning the starter over with the cover off to see if the water pump is working and it appears that it is (the impeller was turning as i was moving the kickstarter). Ive then tried to check the thermostat. My problem is I cant find it? Ive been looking at the parts fiche for the bike. I can see a thermostat cover, gaskets screws and what not but no actual thermostat. So assumed if theres a thermostat cover which I believe is mounted on top of the cylinder head, there would be a thermostat underneath. so i took that cover off and just like the microfiche suggests, there is no thermostat under it. So where is it? Does the bike have one? Cheers
gents.

 

[wrench]

You need to check the impeller and see if it is spinning [loose] on the shaft causing it to not generate enough flow to keep up with the demand.
When it gets warmed up, expansion of the plastic may be the culprit. Another reason to change over to the metal impeller design.

It is a tough call because you symptoms could be caused be several things. If the thermostat has been removed, that could cause a flow issue on the other end of the spectrum. Flowing too quickly to be effective at cooling at low speeds that do not "force" enough air through the radiator cooling fins.

It's all about "gaining therms" efficiently.

 

[normanator27]

You need to check the impeller and see if it is spinning [loose] on the shaft causing it to not generate enough flow to keep up with the demand.
When it gets warmed up, expansion of the plastic may be the culprit. Another reason to change over to the metal impeller design.

It is a tough call because you symptoms could be caused be several things. If the thermostat has been removed, that could cause a flow issue on the other end of the spectrum. Flowing too quickly to be effective at cooling at low speeds that do not "force" enough air through the radiator cooling fins.

It's all about "gaining therms" efficiently.

hmmmmm......... so I'm thinking that while the impeller is off that replacing it with the aluminium one is the go regardless. I cant really seem to be able to find out whether the 08 model comes with a thermostat or not?? From the parts fiche i'd suggest not. I might post a new thread asking that.

 

[Jakobi]

If you have a thermostat it'll be inline behind one of the rads. I don't think they were introduced until 2011, so probably don't have one.

Some signs of rubbing on the tips of the impellor is normal to a certain extent. Mass signs of being rubbed down is not. The area inside the pump cover which looks like its been rubbed is actually machined that way. You can check your tolerances by dummy assembling, but again.. I think the bulk of the issues with clearance kicked off in 09/10 models when they changed to a thinner impellor cover.

Double check the manifold and airboot on the carb, and also check the breather for the tank, and that the tank can flow well with the fuel line off the carb. I run an inline filter to keep crap from making its way from the tank to the carb. Cheap and easy!

 

[Jakobi]

One more thing, if you decide to change the impellor, resist the urge to simply undo the bolt holding it on. On the backside of the shaft its driven by a plastic gear. If you crank on it you risk damaging the gear, so as painful as it is, the best method is to remove the rhs engine cover and use something to hold the actual shaft while undoing the retaining bolt.

Any idea where your jetting actually ended up? Can you pinpoint when the bike began behaving this way?

 

[pscook]

I suspect one of two things, in this order, probably both:
Rad cap
over filled radiators

Bad rad cap will allow the bike to over heat, not just vent. Pressure maintenance allows the bike to operate at a higher stable temperature, a bad rad cap will vent, causing temperature spikes.

Over filled radiators won't allow any room for expansion of the fluid and therefore the rad cap has to vent off. A bad rad cap in combination with over filled radiators will cause over heating, or at least symptoms of over heating (biol over, pinging).

So, get a new cap, like a 1.6-1.8 Bar, and just barely cover the fins in the radiator with water/fluid.

Simple fixes first, then dismiss them with evidence.

 

[normanator27]

]If you have a thermostat it'll be inline behind one of the rads. I don't think they were introduced until 2011, so probably don't have one.[/B].

Ok thanks that rules that out.


Double check the manifold and airboot on the carb, and also check the breather for the tank, and that the tank can flow well with the fuel line off the carb. I run an inline filter to keep crap from making its way from the tank to the carb. Cheap and easy!

Ive checked the manifold and airboot on the carb, theyre all good.
I also run an inline filter, it was on the bike when I got it. Do you change those things after a while or can you clean them? I'm not sure how long mine has been there. I'll check the other things.

 

[normanator27]

One more thing, if you decide to change the impellor, resist the urge to simply undo the bolt holding it on. On the backside of the shaft its driven by a plastic gear. If you crank on it you risk damaging the gear, so as painful as it is, the best method is to remove the rhs engine cover and use something to hold the actual shaft while undoing the retaining bolt.

Any idea where your jetting actually ended up? Can you pinpoint when the bike began behaving this way?

Unfortunately i already have taken the impellor off in exactly the manner in which you have recommended I dont (bad mr impatient). I held the impellor blade steady on the outside and cracked the bolt. It seemed to come off easy enough. Hope I havent damaged anything. I think i'm going to invest in an aluminium impellor while its apart so I dont need to worry about it again. Do you think I should take the rhs engine cover off to install the new impellor?

The jetting at present is N3EG needle, 42p, 175m, AS 1.5 2nd clip from the top for the summer months.
The bike started to behave in this manner after I sent it to the mechanic weve spoken of previously, so who knows what he did to it.