txkawboy

Thanks to all of you. Worked on it this wknd, and as of now it appears solved: short answer is that the fan was causing the boil-over. 1. Drained gear oil again, and it appears that it was indeed only residual water that I was seeing prev. 2. Tested fan via hooking 12v up directly. Would not come on. But, just as I decided that it was bad, I happened to give it several harder-than-normal spins with my finger, and it began to work. ---And since then, it has worked like a charm! (Fwiw, Fan is a jap Mitsuba, and totally enclosed, but apparently the bike sitting up for a year let it form some corrosion from condesation inside it---??). Anyway, rode it in "bypass" mode for about 20mins, then re-connected it to the thermo and retested/rode it. So far so good. I must say that relying so heavily on a fan to keep the engine cool makes me very uneasy, but.... 3. Saw no bubbles re O-ring test, either. Whenever I blip the throttle, it will give a little "spurt", but appears to be more of a surge in flow, not bubbles. I had no boilover issues during rides, so I checked this one off for now. FYI: Earlier I also removed and tested thermocoupler: it consistently closed at 175-F, and re-opened at ~160-F. Also, my fan cuts on consistently when jug reaches 160-F, and causes the engine to continuously operate at 170-degrees F, measured at hottest part of cylinder, (Temp read at Left Rear Upper area; right where cylinder meets the head. (head will only read 130-F). This is running with no anti-freeze at the moment, so figure a few degrees hotter in the future with some a-f mixed, unless I go the aspartame route with this bike. Now the brakes are slightly dragging, so will tackle that next...everything appears straight and bled, but just the pistons are not 100% retracting, probly due to the bike sitting up... Cheers, and thanks to you all again.

Mr. Stoodley, Thanks so much for the reply. Questions: 1. What temp SHOULD the thermo trigger at / fan come on at? 2. Is there a "range"? 3. What temp should the engine operate at, ie, once I do get the fan/cooling fixed, how will I know if the engine is being cooled properly? 4. I did not "flush" the contaminated coolant, but it drained for some time, on the kick stand. Will check that first. If the head's O-ring is bad, will that quickly wear out the seal in ~5mins? 5. I am 99% certain that I did not damage the wp seal upon installation, (I use very $$$ ****zu seal grease on all seal installations, care, etc), so is the "OEM hard brown seal" the best one, or is there a modern Viton rubber seal that is a better replacement? 6. I have never been a proponent of running 100% antifreeze, esp in an engine so needful of colling ability, but since it "does" lube better than a af/water mix, is this what I should do in order to extend wp seal life? (In other words, aspartame and distilled water would be my preference to help cool this hot-running situation/engine, but I am scared to do that, with its apparant wp seal friction-problem---correct?) 7. Did not see "bubbles" when I started the engine up, but did notice that the coolant "spurted" out in a consistent little spurt, as if the waterpump had a lot of "drive"---will test that second. So sorry sir for all the Q's, but there is SO little info on these engines/bikes, and I cannot afford trial [no pun intended] & error!

Hey all, Trials newbie here. Drove 13hrs round trip to get my first trials bike last Sat, but it ain't looking worth it so far! 1. I knew bike had coolant in gearbox oil when I bought it, BUT even tho the owner assured me that the cooling fan would activate if it ever needed to, it has not yet... I installed the updated w-pump kit per the video, added coolant/gear-oil, and then did 10mins of just motoring around the house in a circle... Next thing I know, I have STEAM blowing out of the overflow hose! I quickly read the cylinder temps with an IR temp gun, and got the hottest area to be 218-degrees. Bike never acted over-heated, so I know that this is ~42-degrees hotter than I like a @T to run, but hopefully there was not damage....sigh. Anyway, back to my problem: The sight-glass shows that once again my gearbox is full of coolant, ie, ruined seal in only 10mins of putting around! SO: 1. Did my new shaft/seal fail in just 10mins of putting around, all b/c the fan did not ever come on? (The p-owner told me that the fan only would come on if the motor got hot enough, so I was not alarmed that it did not....sigh again. This trials stuff is aptly named: "trial & error"! LoL--sorta. 2. Also, the video says that the kit should have both a large washer (it did), AND a small washer for the gear--but it did NOT. And yes, my plastic gear is the old one. But neither did the bike have a small washer in it when I dissassembled it---is this small washer needed for the old-style plastic gear, or not? 3. I have had no luck in finding definitive directions (engine/coolant TEMP at which the fan should come on, etc) on verifying the thermocouple. I know how to check the fan, but not the thermo. Anyone? I do not have the $$ to support a hangar-queen, but the bike looked in excellent shape for a '99; basically one-owner, and appears to have truly spent most of its life parked in a garage. There is only one dent in the entire bike (in the silencer), new Michelins, extremely tight engine and wheels, etc... Everyting is all-original, even the original stickers. (It is one of those "Andurro" editions...). BUT, I can NOT afford a bike that is going to constantly need SOME thing...8( Enough whining: ANy advice is greatly appreciated. That little kit alone cost me $57 bucks, and that is gone already.