View Full Version : R1 overheating

08-16-2010, 02:59 PM
Got a 2003 r1 in my rail that always seems to run hot. At first i thought it was the open headers but now ive got that fixed and it still run in the 235 and just feels hot all the time. You can start it and with in 3 minutes feel the heat rolling from behind the seat. have exhuast header wrapped and have pwr radaitor with shround and spal fan. Radiator is mounted behind seat and in front of header but lot of cars are run like this with no issues. i have checked and rechecked the lines over and over. I not as worried about the coolant temp more the fact the motor just always seems hot. sometime uncomfortable to drive with all the heat back there. any ideas what i might be doing work. Back pressure? No thermostat cause this? something with air fuel ratio ? I am open to any ideas you guys might have. I have a big ride coming up and need to figure this out... Motor runs fine and have plenty of power just seem cant figure out the heat issue.

08-16-2010, 03:22 PM
Rail weight and gearing can add up to making the engine work harder under load.

You did not mention what or what size radiator you have.

Also the fact that you are feeling heat withing three minutes tells me the airflow is not optimal. Some good pics from a few angles might really help someone spot some issues for you.

I have seen buggies that flow air in good but not out well and some had cool LOOKING air ducts that were aweful at flowing air.

I am not familier with the 2003 R1 if its carbed or fuel injected but I think its F.I.? If its carbed and lean it will run hot. If its F.I. and somethings wrong with the system the motor can still run lean.

Also the plumbing of the coolant lines may be an issue? Also if its not burped properly (all the air out of the coolant system?)

Could even be the water pump is not pumping fast enough? Maybe the impellor is damaged?

But the heat rolling from behind the seat in under three minutes makes me think of poor airflow first.

Get some pics if you can.

08-16-2010, 03:37 PM
Clue one, no thermostat.........

By having an open water flow you may have the coolant running too fast through the radiator. A thermostat not only sets the water temp, but slows down the coolant to allow the radiator to work.

At the very least you should have a restictor plate to slow down the coolant enough for the radiator to work.

You could put your finger in a candle flame, if you just pass it through quickly you feel no heat, hold it there and get burned.

Same idea with a cooling system, if the coolant just flows though the radiator too fast there is no time for the heat to be transferred to the air, slow it down and it will cool better.

08-16-2010, 03:50 PM
While I somewhat agree with that it does not mean there are not other issues. Yamaha Banshees have NO thermostat at all.

And feeling the heat so quick also points to other issues IMO.

Agian I do not know if that bike (R1) ever had a thermostat. I would guess so and if it DID why anyone would take it out is a mystery.

Also without a Thermo most systems will simply over heat PAST 235 if they are not built to run without one. Like IceFyre said with no thermo often the coolant will not stay in the radiator long enough to dispel the heat it just absorbed fromthe motor and it returns to the motor to hot to cool and the machine will over heat.

The fact that he says it runs at that (235) makes me think the no thermostat may not be an issue. Odd it would hover there. Plus anytime I have seen any vehicle with no thermo they would often run hot. But took a LOT longer to warm up as the flowing coolant when it was cold took longer to heat it alll up as it flowed. Not in three minutes.

To many varaibles here.

08-16-2010, 03:55 PM
are you going with brian and them, to LS?

thermostat seems like an issue to me too.. i have that 600 you sold me, packed into a small spot behind the seats and without a fan i only see 235 and higher when im just putting for 10 minutes or so.

Glock n Ballz
08-16-2010, 04:25 PM
you need a spare R1 radiator? I got one for sale cheap. I think it fits 99-02.

$60 free shipping.

08-16-2010, 08:42 PM
Check for air in the system. Radiator cap needs to be above the head. Over flow tank??
Does the fan run in the right direction??

Bad air flow, how close is it to your seat?
Is your timing retarded?? Are you running lean?

Things to look at as well the ones above posted.

08-17-2010, 12:49 AM
So i should clarify alittle now that am getting lots of ideas to look at. I removed the thermostat because some who had overheating issue before to me to remove it. i have never run a thermostat and am starting to wander about that. now. Also i dont see the coolant temp get to 235 right away. but the motor just seems hot fast when sitting there. when im out riding the temp stays around the 230-240 but you can feel the heat behind you. The radiator is a dual core 22x13x2 so i think it is big enough. I have thought alot of the same things you guys are throwing out im just guess the big thing im want to get figured out is do i have an engine problem or a cooling issue. Sounds like the thermostat and overflow tank, might be the first place to start and what is the best way to get all the air out of the system.??? and the radiator and fan sit about 6 inches in front of header. would putting a aluminum heat shield of sorts in between keep heat off radiator of just cause higher temps becuz of no air flow over the headers???Thanks for the help guys.

MC@ Performance Fab
08-18-2010, 03:18 PM
I have a 03 R1 that I am running without a thermostat and have no issues, not saying it is right but isnt hurting. The fill point might be an issue if it is lower than the motor then the air cant escape. I run the radiator in front of the headers down low in the chassis and use a expansion tank (not a overflow tank) to fill the system and bleed air from the top of the motor. Lack of airflow is most likely the biggest issue.

08-18-2010, 05:48 PM
i have a 03 r1. i run the therostat it did seem to run kinda hot, but to fix it, i run a bigger fan then the stock one, i got a fan off a geo metro, and just zip tied it on, i fits perfect, i have not had any problems with over heating ,but i also changed my gear ratios, what sprocket sizes are you running?

MC@ Performance Fab
08-23-2010, 01:56 PM
PM sent about temp the ecu turns the fan on.

08-23-2010, 03:38 PM
I'm having problems with my 'Busa trapping air and it is common for these to be difficult to remove air.

My latest solution is to modify my upper radiator line with a air bleed valve from Moroso. Upper and lower lines on mine are made of tubing so I can add a threaded bung and the bleeder. Should work good.

Glock n Ballz
08-23-2010, 04:14 PM
oops! I gotta quit drinking at lunch...

08-23-2010, 05:08 PM
the thread is about a yamaha r1.. not a busa

08-25-2010, 12:13 PM
I have been schooled by the chikin. It's an R1, not a'Busa. They have nothing in common . . . or do they?

08-25-2010, 12:25 PM
They are both bike motors?

08-25-2010, 01:16 PM
that was for glock.. it sounded like he thought the thread was about a busa. yea they are pretty much the same.. but problems with air getting trapped in the busa, may not be the same deal with the r1.. they are a different block with different cylinder angles and have different cooling jacket pathways, the r1 may not have the exact same air trapping shape as the busa... sorry gene, was not trying to school. :D

08-25-2010, 02:53 PM
I dont want to jump the gun but i think the problem is solved what exactly did it im not sure. i did about 4 things all at once. First i added a spark arrestor with baffle plates this seemed to make a huge differance on the motor it self. I added an overflow tank. Rebleed the system . And plumbed the thermostat housing breather back in. I had i plugged before. Now she heats up nice and slow to about 190 fan kicks in for about 45 secs and its back down to 160. Only tested in the shop sitting still havent had it out for a ride yet but im really thinking my problems are solved or atleast i hope. THanks for all the help guys....

Glock n Ballz
08-25-2010, 04:50 PM
Yeah Sorry, I wasnt paying attention. Shoulda kept my mouth (fingers) shut.

Sorry for f-in' up the tempo of the thread.

11-11-2010, 06:36 PM
I had overheating problems very similar to yours on mine with the ZX10 motor. I played around with the thermostat, fan, ducting, and all sorts of things. In the shop, it finally seemed like the problem was solved just like yours. Fan came on, temp came back down and everything. On the sand in the hot sun, a whole different story. Still had overheating issues. My biggest problem was I had laid the radiator down flat. That poses two problems in itself. 1) not enough airflow through the radiator even with the fan going. 2) radiator is not designed to work laying down flat. Air pockets form in the radiator and your cooling is reduced (a lot in my case). Another problem was the radiator from the motorcycle is just not big enough. I finally had to bite the bullet and relocate the radiator vertically above the engine where it can get some much needed fresh air (which is probably your problem), and got a bigger radiator. I found this one in ebay for a honda civic that is perfect and cheap. 93 94-96 97 HONDA DEL SOL ALUMINUM RACING RADIATOR+FAN: eBay Motors (item 360318196233 end time Dec-09-10 18:44:18 PST) (http://cgi.ebay.com/ebaymotors/93-94-96-97-HONDA-DEL-SOL-ALUMINUM-RACING-RADIATOR-FAN-/360318196233?pt=Motors_Car_Truck_Parts_Accessories&hash=item53e4a35a09)

If you're still having overheating issues, maybe look into getting more air to your radiator.

11-11-2010, 11:07 PM
single or dual pass radiator? If both inlet and outlet lines are on the same side of the radiator (dual pass) there should be a divider plate built into the side tank to force the water to cross over to the opposite side of the radiator, then back to the lower hose/water pump inlet side. If there isn't a divider plate, the inlet hot water just dumps right back into the inlet for the water pump and the radiator does nothing.

11-12-2010, 10:00 PM
The ones I have are all single pass. I might not have had a problem with my radiator laying down if it was a dual pass radiator.