Trying to fix an issue
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@Stevie-Wonder
My bad, no worries
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@SpookDog
No worries man, I wish it was that, it’d be an easy fix then. But the fact the issue solved itself and ran perfect for a good month after I thought it was that rules out LH crank seal being the problem entirelyIt’s worth noting I tried the old trick of running the bike with the choke on to richen things thinking this might cause stop the heat building and possibly make a difference to how the bike was running.
Unfortunately though this made no difference, temp still carried on soaring and still reluctant to go through the revsThe only place there could be an air leak is where the rubber boot joins the air box… this would then cause a lean running engine.
This leaves me some questions though…
I’m led to believe where the air boot meets the air box doesn’t have to be an air tight unit, is this right?Being a water cooled engine doesn’t this mean as long as there’s sufficient coolant, your radiator and water pump hoses etc are all in good working then even if you had an engine that was run very very lean the heat would be managed?
Or would it be more a case that the cooling system isn’t up to the job to handle those conditions?
As it stands to sort this I have to
- Check there’s enough coolant (I can’t imagine having lost enough to make a difference however the carb warmer pipes are still prone to odd drip or two even when I plugged them so this could have built up over time, always worth checking).
- Check water pump is working
- take zorst off and fit new carb warmer coolant line (as one has a pin prick hole from being nipped by the hose clamp)
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Have you not checked the radiator level yet? I would check that first job. Second would be swapping out the thermostat. Running lean made my bike run ‘hotter’ but not that hot!
Also check for overflowed coolant at the expansion tank filler. Sticky crap below it on the chain guard and swing arm... -
@Stevie-Wonder Air leaks before the carburettor are generally not an issue since you have a carburettor. By that I mean, the venturi effect created due to the air meters the fueling. Since you're only running at normal atmospheric pressures you can rule this out.
With regards to coolant and engine temp, if it's running so lean that the engine detonates then the temperature will spike before/during it seizes. By the time the temperature moves it'll already been too late. You have to keep an ear out for detonation in that case.
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@Stevie-Wonder a lean condition seriously affects the temperature. A main jet 1 or 2 sizes too small can easily make a difference of 20 degrees so an air leak caused by a split rubber can be catastrophic.
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Okay wicked, so we can rule out the rubber boot to the air box not being airtight as not being an issue.
Also the jetting in the carb is the exact same as it’s always been since I’ve had it so jetting shouldn’t be an issue, the only thing that could’ve changed slightly is the air screw.
I’ll keep an ear out for detonation as that’ll give an indicator to wether it’s the engine running lean being the problem or it just being a cooling problem.
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@Stevie-Wonder
Did you check the radiator coolant level?... -
@SpookDog said in Trying to fix an issue:
@Stevie-Wonder
Did you check the radiator coolant level?...Nah after I took it for a ride I just put it back and haven’t touched it since.
Been saying to myself I’d do a little bit here and there after work but this heat has been killing me off and leaving me so fucked where the only thing left to do is have a beer and chill out.
However today I’m going to go through that checklist today and try do as much as I can.
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@Stevie-Wonder Ptsch! What sort of attitude is that! This is perfect trail riding weather. You're young, you should be full of energy smashing it out.
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@SpookDog said in Trying to fix an issue:
Have you not checked the radiator level yet? I would check that first job. Second would be swapping out the thermostat. Running lean made my bike run ‘hotter’ but not that hot!
Also check for overflowed coolant at the expansion tank filler. Sticky crap below it on the chain guard and swing arm...No overflowed coolant. I do have a spare thermostat off a 4FU head I could try too.
@Calum dont remind me
10 hour shifts grafting in 30 degree heat does a number on you though -
And the radiator is full too? If it is then it’s definitely worth trying another thermostat. I don’t even know how many I’ve got in my collection anymore! I brought an old style glass thermometer to check opening temps accurately (only a few £), also to tell me what position on the temp gauge was what, instead of lucky dip!
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Radiator wasn’t full, I have since topped up with roughly half a bottle of putoline coolant.
I’d left to tick over for 10 minutes and didn’t have any anomaly with temp. Gonna take her for a test ride soon. I am hopeful that’s solved it though.
I have noticed a noise that sounds a lot like a bearing of some sort gone in the top end. At first I thought it was just because I had the powervalve cover open that there was more of a raw noise but when you listen I definitely doesn’t sound right
Failing that if a bearings gone that’ll explain a lot!
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@Stevie-Wonder Just watched/listened to your vid. Difficult to diagnose just by listening but I'd say that could necessitate a stripdown to find the cause.
Beforehand though you might want to take a look at the R/H powervalve cover behind the expansion chamber as these have a habit of breaking around the retaining bolt and rattling due to exhaust pressure and the broken bit stopping it falling out completely.
It happened to me once on an RD500LC (it uses the same part x 4) and it made that exact noise. Everyone I was riding with ripped the p!$s out of me because we all thought it had blown up but I rode it 50 miles to get home and just replaced it. Hope that's all it is!
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I think your head gasket may be blown. If you can’t find a leak in the radiator or hoses. Check the level of fluid in the expansion tank. If it’s full to the brim it’s a red flag for the head gasket...
Keep an eye on the temp gauge when riding and check the radiator level after...
Good luck bud!... -
Took the bike for a spin!
Good news the cooling issue was nothing more then being short of coolant. What I thought wasn’t a lot ended up being roughly half to three quarters a bottle of putoline coolant that got swallowed up before hitting the full limit in the rad.
Coolant issue now fixed!
I’ve not had a drop of fuel come out the overflow either, woo!
The addition of a reliable working petcock is a bonus too.
I’ve readjusted the PV so it’s no longer perfectly flush with the exhaust port but align with the hole in the pulley.
This has proven to work a lot better in combination with the OEM pipe I’m running. Torque for days.
The shut off point powerband/power wise is 10.5k with no overrev,
the exhaust port not opening further I’m pretty sure would prevent this anyway however if say for example you where running a ported setup or something like a dep pipe known for its over-rev capabilities then you’d definitely want your exhaust perfectly flush.I enjoy my ride a lot. I actually couldn’t got off the bike and struggled to turn around to go home. So much so I ended up running out of petrol and having to walk 3 miles to the petrol station with a dead phone.
This brings me to the next thing, my bike actually sometimes to run alright suddenly?
Every now and again she’s hesitant to pull through or you’ll be WOT in band and then it’ll cut out then come back on again
I’m also finding you have to roll on the throttle with the Rev’s and that it seems to like going through higher gears more but other then that alright?
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Did you check the coolant expansion tank? That coolant has to have gone somewhere!
Keep an eye on the temp gauge and radiator level, please bud... -
@Stevie-Wonder said in Trying to fix an issue:
This brings me to the next thing, my bike actually sometimes to run alright suddenly?
Every now and again she’s hesitant to pull through or you’ll be WOT in band and then it’ll cut out then come back on again
I’m also finding you have to roll on the throttle with the Rev’s and that it seems to like going through higher gears more but other then that alright?
The cutting out at high revs does sound like it could be your HT lead starting to deteriorate, when that happened to me it manifested itself as a high-rpm (9k +) misfire. Not much fun when overtaking etc.
Made a huge difference when I soldered a new one to the coil output, the job took about an hour so the bike was no longer at operating temperature when I tested it but the front wheel came up as I pulled out of the driveway! 1992 but I'll never forget how it transformed the bike.
If I can dig out a loose coil and some lead I'll do a forum post with pictures
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@HOTSHOT-III what you described is exactly what I’m experiencing.
New racey red NGK HT lead will be getting ordered Friday.
I’ve always wanted one but didn’t actually think they made a difference other then cool points -
