1999 Txt270---water In Gearbox Even After New Pump Shaft/seal

[txkawboy]

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.

Edited September 17, 2010 by txkawboy

[jse]

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.

(1) Did you flush out all the old trans oil with the water in it? It does not take much water to color the fluid and you may need to run the engine and change the oil again, the seal may be fine but you still have residual water.

(2) Coolant in the trans oil will generally not be the primary cause of over-heating and steam out the overflow. In fact, rarely does overheating occur before the rider notices the color of the trans oil is not right. I'm assuming you rode the bike for a time before buying it and if it did not overheat then, there is a better chance that something you did or not do caused the new problem. In that case, you will want to reverse your last proceedure and check each step in the process.

(3) The cause seems to be lack of coolant circulation due to the rapid onset of overheating, see answer #2. It may also be a leaking head inner o-ring that will need to be replaced. Fill the radiator with coolant and with the cap off, start the bike up. If you see bubbles coming up, they are most likely exhaust gas passing past the inner o-ring into the cooling system.

(4) A pan of water warming on the stove, a thermometer and a meter hooked up to the thermoswitch leads will tell you the temperature at which the switch works (or does not).

Jon

[txkawboy]

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!

[lankydoug]

Coolant is more effective mixed 50%. Pure antifreeze does not dissipate heat s well as mix.

[steve1979]

+1 on what JSE said obout the o-ring in the head, good chance if it's been lying in a garage without use it may have perished. I would doubt a new pump seal would fail so quick. And bonus if you whip the head off the barrell you could give it a quick de-coke.

Hope you get it sorted, nothing worse than seeing your hard earned cash sitting there in the form of a bike you can't enjoy.

[gii]

Loads of potential non-issues here, but maybe problems too.

Think about these.

Fill the engine with 50% coolant, whilst doing so, you should squeeze the pipes above the pump to 'burp' the air out of that area.

Run the engine at idle, from stone cold, with the radiator cap off and look down the tube. If you have bubbles coming up the tube in the first 5 minutes or so, the inner cylinder head O ring has blown, if you don't get bubbles till the water boils, it probably hasn't.

Take the wires off the thermo switch and short them together - a short piece of wire or a paper clip and electricians tape works a treat. Start the engine. If the fan is not running then you have a fan problem. If it is running, ride the bike. Half an hour should do it. If you've over filled the cooling system, don't be too surprised to see water and steam, it'll stop after a while. If it doesn't then the inner O ring is leaking under greater working pressures or the water pump isn't working properly, feel the radiator tanks, if the bottom one's not getting warm, the water pump is possibly the problem.

If the bike runs fine and settles down with the fan running constantly, remove the short and re connect the thermo switch. Start the bike and leave it idling, keep feeling the radiator top and bottom tanks. They should both get hot. If they don't, the water pump's not working properly. If they do, then when they become too hot to touch, the fan should cut in. If it doesn't and the water boils, you have a thermo switch problem.

Check the thermo switch as previously described. It doesn't matter what temp you think it should work at, it just matters that it works at all before the water boils.

Make sure you get the radiator cap on properly and tightened down, easy to get it on wonky then you have a totally un-pressurised system

Oil in the gearbox.

Just because you let some of the oil out and re-filled it, it doesn't mean you got it all out. A friend with a drowned Montesa 4RT recently needed multiple (5?) oil changes to get it clean. Did the level go up when you ran the bike? It would if the water had bypassed the seals and entered the gearbox.

Just thoughts....

Edited September 17, 2010 by GII

[jse]

Questions:

1. What temp SHOULD the thermo trigger at / fan come on at?

A: I'm guessing around 180/190 F. (about 82 to 88 C.)

2. Is there a "range"?

A: See above, but still a guess as that seems to be a good operating temp for most engines.

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?

A: Actually I never checked the temp range in an operating Trials bike. With proper jetting, there will be a lack of pinking and good throttle response

and power output will be consistant.

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?

A: A leaking head o-ring will not wear out a W/P seal. The only related problem would be when the radiator overflow tube is crimped and the pressure from a leaking inner head o-ring will force coolant past the seal lip into the transmission case, but that still will not cause wear to the seal, only malfunction.

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?

A: Not that I know of.

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?)

A: A 50/50 mix of auto anti-freeze and distilled water should work fine. My experience is that there is not a seal lip friction-problem in these engines under normal conditions. You do not have a problem with an engine that, as a rule of design, runs hot-you have a problem with one or more failed components that do not allow the engine to normally cool itself. You need to fix the cause, not the symptom.

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.

A; With the cap off, under idle conditions, the coolant usually does not spurt out the radiator neck from my experience.

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!

No problem, let us know how it goes. Trials bikes are a little different to work on than most bike engines.

Cheers.

Jon

[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.

Edited September 20, 2010 by txkawboy