Pressure testing '03 FJR's cooling system?

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james1300

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Pressure testing '03 FJR's cooling system?

I checked my Yamaha Factory manual.

It shows how to pressure test the radiator cap. But, it say's nothing about testing the rest of the system?

I have not gone any farther.

The cap tested OK.

I started the bike up after it sitting all winter.

I can smell coolant.

But, I don't find any obvious leaking.

Nothing under the bike.

The radiator is full.

Suggestions?

Does Yamaha frown on pressure testing?

My Clymer R-1 manual states the factory does not recommend pressure testing the R-1's cooling system?

 
After sitting all winter, and the bike being 10 years old, I'd suggest the suspected culprits would be the coolant pipe O-rings. Those suckers flatten out and get real hard with age and 3,650 days worth of heat cycling. And any minor leak from the coolant pipes are right on top of the motor and won't drip down to the ground...they'll bubble and boil away on top of the cylinder head, stinking up the joint.

That's where I would look...if not first, at least somewhere in the search.

 
If your bike was in cold storage, the rubber parts shrink and a few drops of coolant might escape and get burned off when you started the bike. A heat cycle or two might have cured it. Check for obvious leaks, check the clamps are snug but don't overtighten. An occasional issue with Honda ST's and GL's which have way more hose connections. When I had mine I'd find a puddle on the floor every winter, but all cured itself after that first full temp ride.

 
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After sitting all winter, and the bike being 10 years old, I'd suggest the suspected culprits would be the coolant pipe O-rings. Those suckers flatten out and get real hard with age and 3,650 days worth of heat cycling. And any minor leak from the coolant pipes are right on top of the motor and won't drip down to the ground...they'll bubble and boil away on top of the cylinder head, stinking up the joint.
That's where I would look...if not first, at least somewhere in the search.
If your bike was in cold storage, the rubber parts shrink and a few drops of coolant might escape and get burned off when you started the bike. A heat cycle or two might have cured it. Check for obvious leaks, check the clamps are snug but don't overtighten. An occasional issue with Honda ST's and GL's which have way more hose connections. When I had mine I'd find a puddle on the floor every winter, but all cured itself after that first full temp ride.
Thank you for the suggestions.

I will pull it apart snd look closer for seeping.

Thanks to all for your help.

 
I dont know.

I have not ridden the bike more that 18 miles, Because I was was worried.

Did not want to damage the engine with an internal leak.

 
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My '03 has the same issue... coolant smell at startup. Over a long time, a slight decrease in the level in the overflow. I'm betting on the O-rings, but haven't taken the time to pull it all apart. When I lived in Minnesota, that would have been a winter reason to play on the garage. In Texas? Hate to be down... Ever!

I'll be interested in hearing if you find something different...

 
I have the 3 orings for the coolant pipe on order from 'Glenn'@ FJR Goodies.com

I figured as long as the machine is torn down enough to inspect the orings on the coolant pipe,

may as well replace them.

 
I have the 3 orings for the coolant pipe on order from 'Glenn'@ FJR Goodies.comI figured as long as the machine is torn down enough to inspect the orings on the coolant pipe,

may as well replace them.
Just be sure to lube them with something like "Plumber's Grease" on installation.

Also, if you have access to compressed air, be sure to liberally blow out the wells the coolant pipes sit in. They get full of all sorts of dead bugs, pedestrians, neighborhood animals, sand, dirt, small meteorites and missing children and that crap WILL fall into the cooling system passages when you pull the coolant pipe out of the head.

 
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Mine starting leaking recently from the hose-pipe assembly in front of the engine, behind the exhaust pipes. Tightening the clamps fixed the problem.

I don't trust recovery tanks to tell if there is a coolant leak. Take the cap off to see if the radiator is full to be safe. When I was still working full time, I can't tell you how many overheated vehicles I've seen with full recovery tanks and empty radiators. When a leak exists in the system and the engine cools down, the vacuum that's suppose to pull the coolant from the recovery tank through the radiator cap to fill the radiator does work. The vacuum can be released out the leak instead. The tanks that are under pressure, having a radiator cap and coolant circulating through them, are accurate.

 
Thanks for the Tip's! I will get 'Plumbers Lube', buddy is a plumber.

The compressed air is a good idea.

The second location I will also check out, the hose pipe assembly on the front of the engine

as well.

I did remove and clean the radiator tank and cap surfaces. pressured tested the cap, too.

The radiator was filled to the very top.

Some good cooling pipe 'removal' info. found here>>>https://fjr1300.info/howto/valveadj.html

I should have the O'rings by Tuesday.

 
Called my 'plumber buddy'. He started laughing. He said its called 'Plumbers Grease'.

The 'other stuff' his wife keeps in her night stand...

 
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Turns out that the o'ring's used on the coolant cross over pipe where bad.

"ALWAYS replace these when doing a valve inspection".

The coolant and time had corroded the hex heads so bad they broke off.

So, time and a drill, then re-tapping the head fixed the problem. Along with new orings and lots of anti-seize on the new bolt threads. My bike has 66K on it.

'Desert Valley Powersports' (home of FJR Goodies) did the work.

I looked in the head and said, 'not for me'! Take it to the Pro's!

 
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