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Post by alistair64 on Jan 27, 2019 22:48:07 GMT 1
Hi,
I think my thermostat may be sticking as the temperature needle seems to be heading towards the red when left to idle for a while from cold.
It seems better on the road due to the air flow of course, but I'm going to change it as a matter of course.
I notice Norbo does a 55 degree one as oppose to the standard 71.
My engine is tuned, so wondering what your thoughts are and if anyone has one fitted on a road bike.
I suppose the cooler running means better in terms of power, but the downside is probably increased wear on the top end if the bike is ridden hard due to the tighter tolerances.
Also, would a taller housing be needed, or is it a straight swap?
Thanks.
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Post by 0h5h1t on Jan 27, 2019 23:05:50 GMT 1
Myself and a mate run tuned YPVS's on the road with the 55 degree stat and it helps no end. You'll need a spacer to raise the thermostat housing to allow the deeper stat to open fully. Items 3 and 4 on this page www.mb-designs.co.uk/page12.php?view=productListPage&category=14 we also suffered overheating at standstill and in slow traffic during the summer and fitted large wider Rads also. I can now toast the bike round cadwell park and still not see higher than 54 degree on the gauge. a high flow impeller also helps too when combined with a larger rad. All available from Martin too. |
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Post by dave1963 on Jan 27, 2019 23:10:11 GMT 1
Myself and a mate run tuned YPVS's on the road with the 55 degree stat and it helps no end. You'll need a spacer to raise the thermostat housing to allow the deeper stat to open fully. Items 3 and 4 on this page www.mb-designs.co.uk/page12.php?view=productListPage&category=14 we also suffered overheating at standstill and in slow traffic during the summer and fitted large wider Rads also. I can now toast the bike round cadwell park and still not see higher than 54 degree on the gauge. a high flow impeller also helps too when combined with a larger rad. All available from Martin too. +1 on this i am the other person |
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Post by jon on Jan 28, 2019 8:38:45 GMT 1
I could be wrong but I think the 55 stats from Norbo don’t need the spacer from memory? Best to ask him.
Edit: I spoke to him today and he says you do need the spacer, but he hadn’t them in stock.
I might have to buy elsewhere as I also need one pretty soon.
Jon
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Post by midlifecrisisrd on Jan 28, 2019 10:09:28 GMT 1
I could be wrong but I think the 55 stats from Norbo don’t need the spacer from memory? Best to ask him. Jon I thought the Yam 55 degree stat from the snowmobile was fine too (I take it these are the ones norbo has) as were identical to the original other than a bypass hole It was the rgv type that needed the spacer I may be wrong Steve |
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Post by bare on Jan 28, 2019 18:18:42 GMT 1
Be cautious with retrofitting a 'hi volume' pump impellor.
Water flows that are too fast (faster than designed for) are bad news.. creating hot spots in cylinders.
With ugly result.
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Post by jackjabba on Jan 28, 2019 20:04:00 GMT 1
Shit, now you have me wondering what stat I fitted and will it open fully. I know it was a 55C one. Guess I will be draining the system this weekend.
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Post by budgie on Jan 28, 2019 21:06:15 GMT 1
I could be wrong but I think the 55 stats from Norbo don’t need the spacer from memory? Best to ask him. Jon I thought the Yam 55 degree stat from the snowmobile was fine too (I take it these are the ones norbo has) as were identical to the original other than a bypass hole It was the rgv type that needed the spacer I may be wrong Steve I have a 55 degree stat I bought from Norbo last year, in my track bike, I didn’t fit a spacer, or even know it needed one.? I’ve ragged it round Cadwell twice last season and it never showed above 60 degrees... and I had to tape the rad up to keep the temp up there...? So confused.com now..? Do I need a spacer or not..? Gav |
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Post by alistair64 on Jan 28, 2019 21:46:05 GMT 1
Many thanks for your replies so far guys.
Hopefully Norbo will read this thread soon and be able to comment on his 55 degree 'stats.
Otherwise, seems like the way to go and sounds like a spacer is needed.
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Post by rich on Jan 28, 2019 22:17:41 GMT 1
I tried a 55 degree stat in my Hybrid and it would foul plugs. Went back to the standard 72 degree and no problems since
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Post by JonW on Jan 28, 2019 22:25:05 GMT 1
Snowmobile stat is 82m-12411 if you want one.
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Post by marrcel on Jan 29, 2019 9:01:10 GMT 1
Some may say that a 55c stat gives more cooling power.
In fact designing a heat exchanger it is the temp difference that depents the heat transfer.
So bringing 71c back to 55c will lead to less cooling power in kWatts.
You can also say a hotter rad looses more heat.
So which temp is optimum for operating our 2strokes? And is there a difference between track and street use? I can only guess. 🤔
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Post by bazzer5115 on Jan 29, 2019 9:30:52 GMT 1
Just to complicate your decision,I have built 3 ypvs tuned hybrids and never run any with a thermostat in them,just took them out.
They all run oversize rads(Chinese-no problems)with standard impellers. Tried the high -flow impellers,but made no difference and was worried that the shafts wear quickly.
Just looked at the thermostats and thought even when fully opened they would cause a restriction to flow,so simply took them out!
Bikes run 55-65 most of time,a bit more on hot days when being really thrashed,but soon settle back again.
In my humble opinion a thermostat that is shut then opens to allow more water through quite quickly can over cool hot cylinders too quickly,especially the 72 degree thermostats,which in turn may cause problems.
Don’t get problem with no thermostat a constant flow.
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Post by Norbo on Jan 29, 2019 9:50:30 GMT 1
frankly i dont run a stat
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Post by marrcel on Jan 29, 2019 10:33:21 GMT 1
Just trying to find a conclusion.
Both on track and in the city no stat.
But lets say the Alpes in the summer. On top 2C, in the valley 30C better use a stat?
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horace
Thrash Merchant
Posts: 456
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Post by horace on Jan 29, 2019 10:49:44 GMT 1
I used to drill a two mm hole in stat , but likes been said don’t bother fitting it anymore , there not fitted in lc s.
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Post by bazzer5115 on Jan 29, 2019 11:40:53 GMT 1
Ic350,never head a stat,none of my motorcrossers had a stat.
So it’s not just me,don’t bother with them,just takes a little longer to warm up(don’t thrash them when first started up,to avoid a “cold seizure “),not a problem for me living in a built up area,as I’m stuck in traffic for 5 miles until I can thrash it.
Thermostat I believe is more to do with emissions than anything else,so engines warm up quicker,so they not running on a “richer” mixture for longer period.
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Post by cb250g5 on Jan 29, 2019 12:57:01 GMT 1
I think people misunderstand what the stat does.
The engine produces a certain amount of heat, the radiator disperses it.
The value of the stat sets the point at which the engine has warmed up sufficiently to send the water to the radiator.
Once warmed up, and fully open its value has no effect on the temp of the bike.
I'm not sure about leaving the stat out on the valves, I've seen the train of thought that the cooling system is designed to run against the restriction that the stat, even open, provides, and this helps send the water to the far edges of the head, and without, incoming water can go straight across the head and out again, not cooling as efficiently as possible.
I run the standard stat, all seems OK.
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Post by Mr Kipling on Jan 29, 2019 13:51:22 GMT 1
I never ran a stat in my race bikes or my yammagammas the 50 degree stats need the spacer otherwise they dont open fully....
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Post by Tobyjugs on Jan 29, 2019 16:32:34 GMT 1
I would run a open system or a constant flow thermostat. Is there people on here running a standard YPVS radiator without a thermostat or do you all have bigger radiators?
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Post by budgie on Jan 29, 2019 20:46:16 GMT 1
So guys.... race YPVS .... stat or no stat.... that is the question...!
i have it on a Chinese ebay special Rad.....
Gav
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Post by urbantangleweed on Jan 29, 2019 23:36:51 GMT 1
I drilled two 2.5mm holes in the stat, bike runs about 10 degrees lower than before at about 65° to 69°.
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Post by tacky1 on Jan 30, 2019 1:13:50 GMT 1
You should run a spacer if you run the 82m-12411 stat, It will fit without the spacer, But it will hit the head when it gets hot and that means its not opening fully,
I tested one in boiling water before I fitted it and it pushed the stat right up before it stopped, I fitted the spacer and it doesn't hit the head when its fully open,
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Post by budgie on Jan 30, 2019 8:20:12 GMT 1
Thanks guys, spacer needs ordering I think....!
Gav
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bruno2
Weekend rider
Posts: 83
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Post by bruno2 on Jan 30, 2019 15:53:56 GMT 1
I never used to run a stat in summer.
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Post by reggieperrin on Jan 31, 2019 9:10:54 GMT 1
As others have said, some bikes are designed to run with the stat in place to help control the flow of water in the system.
Without seeing a fluid dynamics illustration, it's difficult to know whether the water flow is affected adversely or not.
When I raced in MRO 400's, some of us removed the stats on our Honda's only to find that the cooling was worse as the design of the stat and it's housing had been done to flow the water correctly in direction and rate.
Just tuppence.
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Post by Norbo on Jan 31, 2019 9:23:18 GMT 1
So guys.... race YPVS .... stat or no stat.... that is the question...! i have it on a Chinese ebay special Rad..... Gav No Air cooler has them of course . LC's don't have them Banshee's don't have them. Just runn the rubber sealing ring and ditch the stat all it means in the bike will take a little longer to get up to hear thats all . and extra few mins . by the time your out your village or town its ready to go or a couple of mins running before you leave the house. Never coursed any trouble for me . and its free |
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Post by alistair64 on Feb 1, 2019 21:55:36 GMT 1
May have to go this way and ditch the 'stat. It seems MBD have sold out of the spacers too according to Martin as they've had a run of orders for them this week. Maybe I should have kept my mouth shut  |
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Post by midlifecrisisrd on Feb 1, 2019 23:19:44 GMT 1
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Post by JonW on Feb 1, 2019 23:24:16 GMT 1
May have to go this way and ditch the 'stat. It seems MBD have sold out of the spacers too according to Martin as they've had a run of orders for them this week. Maybe I should have kept my mouth shut Aint that always the way :/ You could probably make one easily enough if you have a chunk of alloy, or maybe an old spare housing? |
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