No more RICH EFI in the cold! (t-stat install)


80 replies to this topic
  • SEOINAGE

Posted January 06, 2011 - 07:50 AM

#41

Ya thanks for clarifying, I want to go out and try out some new maps now that I got my tuner, but its so stinking cold I would rather just wait, cause it won't run anything like it should.

  • tech24

Posted January 06, 2011 - 08:10 AM

#42

Ya thanks for clarifying, I want to go out and try out some new maps now that I got my tuner, but its so stinking cold I would rather just wait, cause it won't run anything like it should.


You most likely wont notice anything. I have had near zero performance problems just some decel sputtering, poping, and occasional backfire. My main concern is oil contamination. You may not have any problems at all depending on riding conditions. I only have noticed this on a wide open trail I ride where speeds are constantly high. In the woods I have noticed nothing. However the fuel system will still be running towards the rich side without covering the radiators or having a thermostat.

  • Frank_z28

Posted January 06, 2011 - 11:37 AM

#43

I studded my 450 yesterday, so the quickest fix to fuel in the oil is still taping half of the rad?

  • tech24

Posted January 06, 2011 - 11:42 AM

#44

I studded my 450 yesterday, so the quickest fix to fuel in the oil is still taping half of the rad?


Yep quickest, easiest, and cheapest!...but not the most perfect :smirk:

  • Polar_Bus

Posted January 06, 2011 - 12:21 PM

#45

I use these inexpensive temp guages to get a baseline of where my RC nitro engines need to be at for ideal temps. You guys might find it usefull as well when tuning your EFI motorcross bike. They are quick accurate, and you can keep them in your pocket:

http://www3.towerhob...?&I=LXEMG5&P=ML

  • tech24

Posted January 08, 2011 - 01:47 PM

#46

UPDATE! I put the jegs check valve in the LH radiator outlet and took it for a ride. It took a while to heat up being is really cold out but once it did my temp stayed between 170 and 180 degrees. The system is now operating properly B) I didn't take any pics because I forgot my camera and there really isn't any more to see anyway. It was difficult to get the check valve in place as it was almost the size of the hose. It took some work but it was worth it. Off to the trails tomorrow I hope, and will report back with any additional information. :smirk:

  • brentn

Posted January 08, 2011 - 08:47 PM

#47

good news! Post a pic of the finished product so people who want to do the same thing can see how it's done properly!

  • Polar_Bus

Posted January 09, 2011 - 03:01 PM

#48

UPDATE! I put the jegs check valve in the LH radiator outlet and took it for a ride. It took a while to heat up being is really cold out but once it did my temp stayed between 170 and 180 degrees. The system is now operating properly B) I didn't take any pics because I forgot my camera and there really isn't any more to see anyway. It was difficult to get the check valve in place as it was almost the size of the hose. It took some work but it was worth it. Off to the trails tomorrow I hope, and will report back with any additional information. :smirk:


So are you running a "bypass" type system currently with your thermostat mod, or do you still have it plumbed as a conventional single "loop" type system ?

  • tech24

Posted January 09, 2011 - 03:36 PM

#49

So are you running a "bypass" type system currently with your thermostat mod, or do you still have it plumbed as a conventional single "loop" type system ?


Its always been plumbed with bypass same as yout kart but I added the check valve because of the dual radiator setup was allowing a slight amount of backward flow. Through the LH radiator. Its hard to explain without a diagram. I'll see if I can come up with some kind of diagram but not sure how I would do that.



And Brentn I'll try and get some good pics of the entire system it may be hard to see check valve but I'll try next time its clean and in the shop, might be a few weeks but i'll be sure to update

  • tech24

Posted January 09, 2011 - 03:42 PM

#50

I did a little more monitoring today. I rode a small tight loop in the woods and it the coolant temp remained a pretty steady 165 degrees through several laps. I then shot out through an open field at close to top speed and the lowest reading I ever got was 159 degrees. This is plenty acceptable in my opinion as is was 25 degrees out. I had no signs of excessive fuel, no sputter or pop as I had before. There was not even a hint of fuel smell in the oil. So I'm gonna call this one a success. I still want to monitor it on the really fast trail where I had most of my issues but I see no reason for the coolant temp to ever drop below 160 from what I have seen today. If I have any more findings I will post them and I'll get some more pics up!

I'd guess that without the t-stat I'd be seeing temps below 100 degrees especially when I went fast through the open field.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • brentn

Posted January 19, 2011 - 02:24 PM

#51

Took my bike out today, it was about -5 or so out not too bad.

Had the trailtech vapor hooked up so I could monitor temps from 39C all the way to boiling. The temp sensor will only show up if the coolant is at or above 39 degrees.

Warmed the bike up to about 80 degrees and by that time (a good 6 minutes!) I was all patched up for cold riding. Took it down the first fire road in 5th at WOT and the temp plummeted from 85, to 65, then 45, then --- which means lower than 39 degree's within about 30 seconds....
I took it out on the trail for some first gear only action which was pretty slow going but high revs... I was barely registering, the temp was hovering from --- to 45 degrees or so...
I have a nice black soot ring around my silencer inner neck, so the bike is def not at a good combustion temperature.
I can't afford a Tstat install, so I'm going to try and block an entire radiator and see how much it helps.

These rads are just wicked at thermal transfer!

  • tech24

Posted January 19, 2011 - 04:34 PM

#52

Yeah I was amazed how efficient these things are. I trying to find a cheaper t-stat option. I need to look into the KTMs, it wont be much cheaper and may still need a check valve. I fear that they are the input style like the aprilla but I haven't found any coolant flow diagrams yet. I tried to download a manual but link or computer is F ed up. Since you can monitor temp now I'd say covering them up is a great alternative. You may need to block both with some small holes in the tape or cardboard or something. I did notice only my right radiator ever gets warm which means the t-stat doesn't stay open long enough for coolant flow to pass through the check valve in the left outlet so even 1 radiator is doing some awesome cooling.

  • Polar_Bus

Posted January 20, 2011 - 02:55 AM

#53

Yeah I was amazed how efficient these things are. I trying to find a cheaper t-stat option. I need to look into the KTMs, it wont be much cheaper and may still need a check valve. I fear that they are the input style like the aprilla but I haven't found any coolant flow diagrams yet. I tried to download a manual but link or computer is F ed up. Since you can monitor temp now I'd say covering them up is a great alternative. You may need to block both with some small holes in the tape or cardboard or something. I did notice only my right radiator ever gets warm which means the t-stat doesn't stay open long enough for coolant flow to pass through the check valve in the left outlet so even 1 radiator is doing some awesome cooling.


I don't have much experience monitering my YZ450 temps in winter, but my race kart has a Mychron EGT/coolant temp readout, and in the summer I'll be running about 125F +/-, but in the cooler fall (before the addition of the bypass system) I was struggling to reach 100F . Granted I'm talking 2 stroke, but it gives you an idea how varied coolant temps can be, and this broad engine temp variances aggravates trying to achieve consistant clean jetting. Keep at it sounds like your making great progress ! Just as an FYI here's a link to my Mychron. They use a 9V battery so you could easily run one on your YZF ! They monitor RPM's, EGT's and engine coolant temp.

http://www.aimsports...ron4/index.html

  • Rabb

Posted January 21, 2011 - 11:29 AM

#54

Can anyone tell me at what (air)temperature I should cover the rad? And do you cover the left or right? Whole radiator or just half?

  • tech24

Posted January 21, 2011 - 11:41 AM

#55

Its really hard to tell as its really dependent on terrain. Bike speed and engine load vary so much but I'd say anything below 40 - 50 degrees its not going to hurt anything. I haven't experimented with covering the radiators obviously but with the t-stat only the RH sees much hot coolant so 1 radiator still does a great job of cooling. If I were to cover them I think I would try covering both with cardboard with holes in them large or small depending on conditions.

  • brentn

Posted January 21, 2011 - 12:04 PM

#56

Can anyone tell me at what (air)temperature I should cover the rad? And do you cover the left or right? Whole radiator or just half?


IMO anything around 5 degrees above zero (celcius) and below you should be covering up the rad. Depending on the riding I suppose.
It was -5 here when I was riding and I could have easily covered an entire rad to stay in the temps, I'm guessing that I probably would have had to cover one and then half of the other...

  • brentn

Posted January 25, 2011 - 01:36 PM

#57

Bump for pics of the finished install!!!!
Can we get a couple angles so we know where everything goes?

  • tech24

Posted January 25, 2011 - 02:22 PM

#58

Bump for pics of the finished install!!!!
Can we get a couple angles so we know where everything goes?


yeah I gotta do that just had my bike in the shop too but forgot my camera. Thanks for that, I'm trying to forget saturday. I was in the shop for 18 hrs working. Had to put a radiator and belts on my truck and every adjusting bolt broke. Had to put hub bearings on a cavalier. Had to overhaul a yz250f which was being a pain. Took me 3 hrs to was my bike because it was freezing as soon as the water hit it. Theres more....:thumbsup:. Weekend after this I'll put something together even I gotta use my cell camera because I'll probably forget the camera again.

  • brentn

Posted January 26, 2011 - 12:56 PM

#59

I am now 95% sure that the Tstat is a must have for this bike. The engine runs WAY better when temps are up.
Took the bike out to the trails today with one rad completely blocked from the front with a perfectly piece of cardboard behind the left louver. After the bike warmed up the temp was hovering at about 60 degree's celcius, which is just not hot enough, but better than having it go down to 30 degree's like last time. There were a few trails that were really snowy and slick and I had to keep it in first for a good 30 minutes of trail lugging with lots of higher rpm's. Temp stayed at about 74 degree's which is just about right.

Oil didn't turn black this time like it did last time when I took it out and the engine temps weren't registering 40 degree's. Secondly the bike ran better, revved quicker and holding throttle positions it just sounded leaner.
Kicker was that it was 8 degree's out today which is really warm this time of year. 8 degree's is like a rainy day in june with lots of cloud cover, and I had one rad completely blocked off.
It's obvious the bike's cooling system was made for MX/SX where you have lots and lots of high rev with load with lots of small stops and only short straight aways. Gotta have a good cooling system to keep temps down when riding like that, so yamaha of course put it on the bike.
I think using a T-stat even in the summer will help quite a bit.

Point being here, I think I'm going to order one.

  • tech24

Posted January 26, 2011 - 01:38 PM

#60

Thats good news, It does seem to run a tad better IMO also. The only problem with ordering the t-stat I have is I took the last one on that the guy had. Now he may order a few hundred more and have them in stock when kart season begins but I have no idea when that is.

Guhl racing has the exact same housing but with a 55 C element for 2ts. In their FAQ they say no other temps available, which is dumb because all they need is another 2 dollar element to put in it. Maybe I'll email them and see what they say.





Related Content

Wiki
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info


Articles
  • 0 replies
Forums
Photo

Megabomb Fitment by 288yz450


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply
Forums
Photo

yz250x vs 450 4t comparisons (preferably desert riding) needed by JakeNorthrupYZ450F


Dirt Bike   Make / Model Specific   Yamaha   Yamaha 2-Stroke
  • 9 replies
Reviews

Yamaha YZ450F 2017 by Chris.GVS


Yamaha YZ450F 2017
  • - - - - -
  • 0 reviews
Forums
Photo

2016 YZ450 by CaptainKnobby


Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies
 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.