Well I baught my Raptor in September of last year ..rode it for a few months ..more like 3 then ripped it down and made it a 686 ..Porting, Polishing, Valves all that ..then raced it a couple times last winter ...well last week I was just going down the road ..after riding for about 10 miles.. and it started to loose power and would only run in gear while slowing down..then when I stopped it quit and has not run since..when I get it ripped apart in the morning I will see what is wrong ..sounds like a hot seize to me ..I think the cooling system failed in some way .but I won't know til disassembly. My post is ..anyone have cooling system troubles with thiers?

 

Raptor690,

Sorry to here about your failure.

My stock 01 Raptor has had no cooling problems.

Chet

 

Sometimes doing a search from past posts will get you what your looking for. This time I will help you out, as I just copied and pasted some info on this subject from the past.


1- On almost all Raptors, I have found that the thermal fan switch does not work. This is not the thermal switch at the bottom of the radiator (that is the temp light switch) --- it is the one on the top of the radiator. I simply add a toggle switch in a good location so that I can click it on if I am moving slow or just following a race. I never have a problem.


2- Had the same problem when I first assembled my motor. Once the motor got warm and I was on the throttle hard it would blow all my antifreeze out the overflow. Head gasket wasn't sealing correctly, Raptor720 told me that I got an old design Cometic head gasket from JE with my piston. I ordered just the head gasket from Trinity and some Threebond and I haven't had a problem since.

3- Regarding the thermal switch. I also wired mine to a toggle switch, I run my fan all the time. Hasn't caused any charging problems and I know the engine is always as cool as it can be.


4- Test the thermal switch. Remove it from the radiator, place it on the stove in a pan with about 3" of water. Connect a Ohm meter to the two leads on the switch. PLace a thermometer in the water and note at what temp the switch closes the circuit. Mine was 212 degrees -- if it worked at all.



Let us know what you find when you get it torn down. I too, had a 686 let go, but it was the rod that failed not over heating. I never had any heat problems with mine stock or as a 686.

Swy

 

The cooling fan is only needed if you are not moving air through the rad, idling or stuck. If you were driving down the road at anything more than 10 mph you would be moving more air than the fan would be. So I don't think that your trouble would be related to any type of fan failure. I hope it's not to $$$$$. Let us know, good luck![img]i/expressions/face-icon-small-shocked.gif[/img]

 

I've never had a cooling prob with my 02. The fan does come on but only after I've been riding slow for a while, I open it up & it goes off. My temp light has never come on.

 

<< Sometimes doing a search from past posts will get you what your looking for. This time I will help you out, as I just copied and pasted some info on this subject from the past.


1- On almost all Raptors, I have found that the thermal fan switch does not work. This is not the thermal switch at the bottom of the radiator (that is the temp light switch) --- it is the one on the top of the radiator. I simply add a toggle switch in a good location so that I can click it on if I am moving slow or just following a race. I never have a problem.


2- Had the same problem when I first assembled my motor. Once the motor got warm and I was on the throttle hard it would blow all my antifreeze out the overflow. Head gasket wasn't sealing correctly, Raptor720 told me that I got an old design Cometic head gasket from JE with my piston. I ordered just the head gasket from Trinity and some Threebond and I haven't had a problem since.

3- Regarding the thermal switch. I also wired mine to a toggle switch, I run my fan all the time. Hasn't caused any charging problems and I know the engine is always as cool as it can be.


4- Test the thermal switch. Remove it from the radiator, place it on the stove in a pan with about 3&quot; of water. Connect a Ohm meter to the two leads on the switch. PLace a thermometer in the water and note at what temp the switch closes the circuit. Mine was 212 degrees -- if it worked at all.



Let us know what you find when you get it torn down. I too, had a 686 let go, but it was the rod that failed not over heating. I never had any heat problems with mine stock or as a 686.

Swy >>



This needed to be repeated!!!!!!!!!

Chet

 

r690, sorry to hear it man. good luck. maybe it's something electrical like a loose coil wire.[img]i/expressions/face-icon-small-confused.gif[/img] my light has never come on and the fan does regularly.

 

Hello everyone, Most of you I've never talked to, because mostly I live in my lil BOMB forum. Anyways sorry to hear about your motor croaking. When you get it rebuilt and want some added cooling just for good measure, I would email, DirtMods98@aol.com and ask him for a list of stuff he sells. He sells add on radiators, oil cooliers, every gauge imaginable and other lil goodies. Well good Yamaha guys and also if anyone is from central to western PA, drop me a PM.

 

Well being as I only had a hour to fix the Raptor today (to many other things to do) I tested the TEMP light ..it works ..but the sensor for the fan and the light do not..I only took off the valve cover and so far all looks &quot;normal&quot; everything works fine ..Nothing smelled burnt and Enough oil and water (tested for flow)so this is leading me to think maybe the head gasket has blown out ..this would explain some of the weird noises I heard just before it stopped running (sounded like the header pipe was slipping off or loose) Since I am taking the motor out of the chassis to clean,paint and polish it, I did not do a compression test. If the head gasket did blow I have to get the gasket surface redone anyway. Will post more tomorrow..

 

Well I finished the tear down ..It wasn't the head gasket..It was the dime sized hole in the top of the piston..Without being an expert I would say this is the problem...The hole itself looks like a defect in the piston because it's not a burnt hole (it's like a rust hole is the best way I can describe it)Unless something broke in the transmission and sent something up from underneath the piston to make a hole like it did ..I didn't tear it down any farther because I'm waiting on parts for my new 770 (crank,piston) from Powroll And I also have a Banshee project going on (putting it back together) I had the frame powder coated and I'm finishing building the motor ..So the Raptor is on the back burner for now.