Overheating issues, need of help.

[murc585]

Hello everyone,

I'm the owner of a 2008 red 250r and I am in love with this bike. I have done a little work on it and it has been running well all summer.

I have added a full Area P exhaust, dynojet jet kit, k&n air filter, removed the clean air system, added hid's, and I have also recently switch to Shell Rotella T sythetic oil (5w-40?).

I went on a long trip two weeks ago which included a lot of highway driving. The problemi am having with my bike it that it sometimes overheats on the highway. It did this to me 3 times and the first time took a lot to get it starting again( had to hold the ignition for a while). The first time I was trying to keep up with an R6 so that is understandable (cruisig at about 11700rpm) and the other two times I was cruising at about 9200-9800rpm. I am actually waiting on the sid of the highway right now waiting for it to cool down.

Is this normal for such a small bike? Is cruising at 10,000rpm a big no-no? I remember it overheating only once when it was stock but it started right back up. Could it be this new oil? I'm pretty sur the jetting is correct, I get a nice chocolaty brown residue at the end of my exhaust and it go through the revs beautifully with no hiccups. I'm starting to get a little irritated with mybike doing this and I understand if it's just too small for highway. Do any of the 250 gurus have any idea what could be going on or should I start keeping my speeds down?

I would greatly appreciate any piece of advice.
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[SteveL]

How many miles do you have on it, it may not be run yet.

Steve

[murc585]

I have 8500kms on the bike, which I think would be around 5500-6000 miles. Also, my coolant levels seem to be good, along with oil levels and I am using a Fram CH6012 oil filter.
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[bob706]

Does the radiator fan ever run?

[SteveL]

You should look at the plugs it could be that you are running too lean there is more than enough air flow for cooling once underway, my fan never ran unless I was in heavy traffic with high temperatures.

Steve

[RaceBikeRentals]

How do you know its overheating? Is the red light coming on? Is the fan coming on? You're cruising at 10K rpms... that works out to about 85MPH... if its VERY hot outside, I could see that you might be overheating. Try slowing down a bit to 110 clicks or so and see if that improves the situation. Get a Daytona temp gauge so you can monitor the temp more accurately.

[Alex]

If coolant levels are good, oil is recently changed and oil level is good, then overheating on the highway is a bit unexpected. If the water pump failed completely, it would overheat immediately in all conditions, and that's not the case. Once up to speed on the highway, whether the fan works or not would be a moot point; the radiator should be getting more than enough airflow.

[kkim]

yes, how do you know if you are overheating?

also, which K&N filter do you have... a drop in or separate filter w/ no airbox? Jetting specs?

[Ramen]

Check your coolant/antifreeze level. It was several thousand miles before I discovered the stealership penny pinched me on that one.

[bob706]

Maybe the thermostat is on the fritz. Might want to flush the coolant if this has been a recurring thing.

[murc585]

I'm in Canada, southern Canada; but it still gets hot. This morning is was about 20 degrees celcius so not too cold. I'm pretty sure my fans run, but most likely not on the highway. I will hear them from time to time when i stop then engine but that's only really on a hot day of city riding. I think it's overheating, this is what happens:

I'll be cruising, I feel like my engine is having little hiccups, my speed starts to decrease, giving more throttle does nothing, more and more hiccups, red light comes on, I pull in the clutch, and finally my engine stops so I get into neutral and coast to the side of the highway. At this point I have to wait about 10-15 min for the bike to start up reliably and I get up and go, as well as drive like an old lady at this point, scared that it'll happen again.

I have the same K&N R-0990 as you kkim, actually most of my mods were copied off of you, because they are sweet, haha. Yes, the entire airbox is removed. I actually used the exact settings from the dynojet instructions, which were the settings recommended for a 250R with an snorkel removal. These settings I use are:

E-clip on groove #3 from top on the dynojet needles along with 2 washers on top.
DJ098 main jet recommended by dynojet for aftermarket exhausts.
Mixture screws are out 3 turns.

I'm at school with little to no tools ATM, so the next thing I'll check are the plugs.

For the plugs, those this sound right?:
Too Lean - white tip
perfect - chocolate brown tip
too rich- black tip

[murc585]

maybe flushing the coolant it will be... I actually have little faith in my stealership, with experience from friends there they don;t do what they actually say they do. Maybe I'll try someone around here. I'm planning to move up in engine sizes soon though, the 250 doesn't fit my lifestyle, I do too much highway so maybe I'll try to sell, make a little profit and move up to it's bigger brother the ZX-6R.

[kkim]

Originally Posted by murc585

I'm in Canada, southern Canada; but it still gets hot. This morning is was about 20 degrees celcius so not too cold. I'm pretty sure my fans run, but most likely not on the highway. I will hear them from time to time when i stop then enginer but that's only really on a hot day of city riding. I think it's overheating, this is what happens:

I'll be cruising, I feel like my engine is having little hiccups, my speed starts to decrease, giving more throttle does nothing, more and more hiccups, red light comes on, I pull in the clutch, and finally my engine stops so I get into neutral and coast to the side of the highway. At this point I have to wait about 1-15 min for the bike to start up reliably and I get up and go, as well as drive like an old lady at this point, scared that it'll happen again.

I have the same K&N R-0990 as you kkim, actually most of my mods were copied off of you, because they are sweet, haha. Yes, the entire airbox is removed. I actually used the exact settings from the dynojet instructions, which were the settings recommended for a 250R with an snorkel removes. These settings I use are:

E-clip on groove #3 from top on the dynojet needles along with 2 washers on top.
DJ098 main jet recommended by dynojet for aftermarket exhausts.
Mixture screws are out 3 turns.

I'm at school with little to no tools ATM, so the next thing I'll check are the plugs.

For the plugs, those this sound right?:
Too Lean - white tip
perfect - chocolate brown tip
too rich- black tip

your main jets are waaaay too small. change it to at least a DJ 106 or 108. I hope you have not done permanent damage.

http://www.ninjette.org/forums/showthread.php?t=10208

[CRXTrek]

The dynojet #98 is not big enough for the airbox removed

[murc585]

Originally Posted by kkim

your main jets are waaaay too small. change it to at least a DJ 106 or 108. I hope you have not done permanent damage.

http://www.ninjette.org/forums/showthread.php?t=10208

kkim, I though factory pro and dynojet used different number schemes though. all that comes with the stage II kit (recommended by Area P) are the DJ094, 096, 098, and 100's.

[murc585]

now you've all got me scared. I rode from toronto, ontario to bar harbor, maine on these settings, and back!

[murc585]

and like I said, the largest main jet that comes with the kit is the DJ100

[CRXTrek]

Originally Posted by murc585

and like I said, the largest main jet that comes with the kit is the DJ100

because the kit is not made for a removed airbox

[murc585]

Originally Posted by CRXTrek

because the kit is not made for a removed airbox

I can;t even find another dynojet kit for our bikes. should i go out and get the factory pro ones?

..boy do I feel stupid right now

[CRXTrek]

Originally Posted by murc585

I can;t even find another dynojet kit for our bikes. should i go out and get the factory pro ones?

..boy do I feel stupid right now

Here's the link for jets at dynojet.
http://www.dynojet.com/jetkits/jetassortment.aspx
You may want to call them.

[kkim]

Originally Posted by murc585

now you've all got me scared. I rode from toronto, ontario to bar harbor, maine on these settings, and back!

you should be very concerned. these are the conversions between different brand main jet sizes.

Width------Keihin # -- DynoJet # --- Mikuni #
0.0350---- 92.5--------- 92----------- 86.3
0.0360---- 95----------- 94----------- 88.1
0.0370---- 97.5--------- 96----------- 90.0
0.0380---- 100---------- 98----------- 91.9
0.0390---- 102.5------- 100---------- 93.8
0.0400---- 105--------- 102---------- 95.6
0.0410---- 107.5------- 104---------- 97.5
0.0420---- 110--------- 106---------- 99.4
0.0430---- 112.5------- 108--------- 101.3
0.0440---- 115--------- 110--------- 103.1
0.0450---- 117.5------- 112--------- 105.0
0.0460---- 120--------- 114--------- 106.9
0.0470---- 122.5------- 116--------- 108.8
0.0480---- 125--------- 118--------- 110.6
0.0490---- 127.5------- 120--------- 112.5
0.0500---- 130--------- 122--------- 114.4

[HKr1]

Originally Posted by murc585

I can;t even find another dynojet kit for our bikes. should i go out and get the factory pro ones?

I would just drill out the dj94 & 96's.

[murc585]

Well I called a reputable honda dealership where I currently am for school and they said they sell individual jets for $4, so that settles that but I think I might let them do the work and get it all tuned properly an they can asess the damage if there is some. I think after it's all fixed up I'm gonna sell the bike, carbs aren't really my thing. I cannot thank all of you enough, the support on ninjette is incredible! I'll be back once I move up to either the cbr600rr or zx-6r next spring, I really want something bigger.

Again, I really appreciate the help, I just hope I didn't ask too late. What kind of damage do you think I could be looking at? Head gasket and/or pistons?
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[RaceBikeRentals]

They'll need to tear the engine down to assess damage. I doubt you're going to want to go to that expense. If there is damage, you're looking at some crispy valves and more than likely piston damage. Some of the others with more mech knowledge than me would know better.

[kkim]

I think either a compression or leak test would tell you the relative health of the valves and/or rings.

Make sure they are selling you Dynojet main jets as the numbering system is different than the stock Keihin main jet numbers. You can use Keihin jets in there as well and I think they are easier to get than DJ ones.

Use 110-112 Keihin or 106-108 DJ jets.

[noche_caliente]

I hope it works out ok for you

[ninjabrewer]

Originally Posted by RaceBikeRentals

you're looking at some crispy valves and more than likely piston damage.

dumb question here, why? Why is his engine possibly damaged? Teach me here o wise ones.

nb

[kkim]

if the jetting is too lean, denotation and heat sets in from too much air in the air/fuel ratio, gets too hot and the valve edges usually start to melt/burn.

best way to check for a leaky valve/holed piston damage is to see if the cylinder is still able to maintain compression by doing a leak test and/or compression check.

[g21-30]

Even if you're not experiencing detonation, when the bike overheats, denotation can also occur as a side effect and not be related to a lean condition or wrong octane gas! Could be as simple as a sticking thermostat.

For general knowledge, check this out:

http://www.aa1car.com/library/overheat.htm

[ninjabrewer]

Oh ok, thanks

nb

[Ken08Ninja]

You need to put in bigger jets like already mentioned. Also do another oil change, you've overheated the bike and the oil will breakdown.
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[KELPHYN]

Just a question first. You said the bike was runnig fine most of the summer? Was that before or after the mods? If before the mods and the over heating after the mods, I would be inclined with going with the general consenses here that it is the jetting. If it was running fine after the mods and just started to overheat, lose power; hard to start, lose of gas mileage also perhaps? I might be thinking 'time to check the valves'. 8500km seems a little soon but you never know. Just another thing to check, but should be done before you consider tearing the motor apart. Oh one more thing. Are your pipes starting to turn blue at the head? That's another good indicater that your running to lean for an extended period of time. Anyways just my two-bits, but check your valves.

[murc585]

I've had this bike new since October of 2008. I go to school 200km away from my home. In late october of 2008 I was doing this ride (after my 1000km break-in period, in which I did 3 oil changes) and I had this issue. I didn't know what it was at the time but I remember my speed going down and I could no longer accelerate. I pulled over and let it sit for about 5 min and it went on fine the rest of the way. I don't remember the engine stuttering though or the red light showing up. I think I was also seeing how fast I could go on the bike on that ride though, which probably didn't help much.

I did the mods in one shot (both exhaust and K&N air filter) in May of 2009 but I didn't do much highway, if any until late august. I did notice last night that my pipes were turning blue at the base of the exhaust headers! I'll let the mechanics know all this info and tell them what's been recommended to me by this forum. Hopefully it doesn't take them too long at $75/hr. The bike has never had any issue starting though and I usually get about 380km on a tank (and thats about a 16.5 litre fill up on the 18 litre tank)

to G21-30, I've been using 91 octane.

[kkim]

have you ever heard like a "rattling noise" when accelerating hard?

[murc585]

Honestly, I can't really hear anything but my area p and wind when I'm on my bike.
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[HKr1]

You mention it runs OK after it cools down. So I wouldnt be too worried right now. Get it jetted properly and see how she runs

[murc585]

I appreciate the vote of confidence. My buddy knows the mechanic at the stealership and I told him
my situation. He starter her up and told me it should be fine. I hope he's right. I asked them to do a compression leak test (thanks kkim) and gave them the jet sizes you all recommended for me so things should be alright I hope. I can't say thank you enough, too bad I didn't catch this before.
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[kkim]

Hope everything works out for the best, Mat. Please let us know what the outcome is.

GL

[KELPHYN]

Okay back with more thoughts. You say that you are going all and just lost power. A few hiccups, then nothing and the light came on. Was it just the temp light or did the oil light come on also? If both lights came on that would indicate your engine comepletely stalled out and you were just coasting, the rear wheel spinning the engine not the engine turning the wheel. And since this was also an occurrance from before your mods, it is probably unrelated to the overheating, jetting problem. Although get the jetting straighten out.
The way your engine dies, sound allot like how my old quad acts when it runs out of gas. A few hiccups and then your just coasting under the bike momentum (quad is an automatic so no clutch to pull in) Any way what I'm getting at is you might have a fuel delivery problem that is intermittantly starving your carbs (which could also cause lean running conditions). INTERMITTANT that's the big problem could be a number of things.
-a pinch/kinked gas tank vent hose.
-the vaccum hose operating the petcock might have crack or leak at one of it's fittings, causing it to shut off once in awhile.
-the fuel line itself might be pinched/kinked
-incorrect float levels ( although not likly as that would be more of a constaint problem than intermittent)
-faulty petcock
-petcock not set all the way to the on position
Sorry for giving you more things to think about but this internet diagnostic thing can only be about suggestions and hope you can weed through them all and find one that you haven't tried/thought off. Sometimes it's something as simple as a kinked hose. Well good luck and keep us posted as to what you finally find.

[murc585]

I completely forgot about this post, it has been ages since I've been able to ride my bike, it's too cold here in Canada. Anyways, I'd like to give any of you who are curious an update on the situation. I brought the bike in with a summary of the mods I added to the bike and some of your suggestions as to what needs to be done. Two weeks after I brought it in I got an update on the bike confirming that yes, it was running lean and that the compression test went A OK. They put in the DJ112 main jets in and gave me some crappy news about my carbs. It seems both my vacuum diaphragms (is that the right word, it's been said in so many different ways had been pinched and needed to be replaced. The repair shop quoted me $150 for each so I went shopping for them on my own online and the prices were just about as bad. After lots of reading and searching I found that a member of the 250faq site had the same issue and it was suggested to him that he just buy some used carbs online and that would be much cheaper. It just so happens there were a set of '08 used carbs on ebay for $99. I asked if the rubber diaphragms were still intact and they confirmed this. After 2 weeks I received the carbs and they were in pristine condition. I dropped the carbs off at the bike shop and they had it ready for me the next day. It was so service, but good service. The best part is they only charged me $100 for labour along with the new jets! I've had the bike for about 2 weeks and for the little time I have had to ride it I can safely say that it's a new beast. The power feels so linear; I used to get hiccups at certain RPM ranges, but it pulls hard now all the way to redline!

I wouldn't have had the motivation to bring it in if it weren't for your advice and I greatly appreciate that. Sadly, I am selling the bike. Cash is tight at the moment and I am in my last year of Mechanical Engineering (too much school, no time for work). I'll be sure to visit again when I have the cash to move up on the power scale, I'm thinking BMW F 800R!