Now it's my turn to be frustrated,running hot and knocking..

[admin]

If you never run the bike hard then preignition/pinging/knocking/detonation is a definite possibility due to carbon build up in the combustion chamber which glows red hot hot like charcoal and then preignites the fuel/air mixture before the spark does. A good liquid top cleaner is vailable from a G.M. dealership parts department and can clean this carbon out or you can use my old method of dribbling water into the intake while the engine is running at about 3000 rpm which effectively steam cleans the carbon out.

[bs175dths]

as far as adding the water to the intake, just make sure you don't add so much water as to cause the engine to stall. Sometimes it can be difficult to restart. Another method for cleaning off carbon build-up is to run the bike at a high rate of speed for a long period of time (ROAD TRIP!!!!) My older brother had a mechanic tell him to take his GMC Sprint (GMC version of a Chevy El Camino) out on the highway and drive it in excess of the posted speed limit for an extended amount of time to clean the carbon off the inside of his 454ci. [-X (of course he would deny this if asked) Or do the water treatment. After a run on the highway, the truck ran smoother, stopped 'pinging' and got better mpg. Once a month he would take her out and run her and never had that problem again. :d
Something else to consider is changing the plug temperature.
I personally favor the road trip solution. :YMAPPLAUSE:

-Ride On ~O)

[admin]

You're right on about the water. Essentially, what is needed is a stream of water about 3/16" in diameter for about 20 minutes at 3000 rpm is what I have found to work. Not too sure about changing the plug temperature because too hot might cause detonation and too cold might cause plug fouling and misfire depending on engine temp and load, but, hotter plugs with an oil burning engine will defintely stay cleaner longer. I like running my bike hard, but, anymore it seems like there is a cop on every corner waiting to hunt you down so the chemical or water method of cleaning out the carbon might work best for most, but, if you have a dragstrip close by go for it and enjoy the decarbonization process that leads to a better running bike.

[unkelbob]

You might try running some sea foam through the fuel system by adding about 1/2 cup to a tankful , it acts as a decarbonizer as well as cleaning the system. Another old trick is to add a teaspoon of automatic transmission fluid to your tank, it eventually atomizes through the carbs and decarbonizes the top of the piston. Neither will do any harm, I have done this for years to keep my Honda generator clean and have used it on my bike at spring start up. *-

[desertrefugee]

To get back onto my particular issue - I do not have a detonation problem. This is top-end valvetrain noise. And I can assure you, I do not have appreciable carbon build-up. I do NOT baby this machine. I RIDE it. I don't beat it, but it is not one of those that stays below 4500RPM. I have always been more performance oriented - and a long list of bikes and cars over the years would attest to that. (I won't bore you with that. But, NONE of them were MOPAR....or Harley)

So, I am less worried about the 'clatter' now that I have more or less isolated its source. Also, thanks to someone in this thread, I went to youtube and listened to some of the poor GL1200's on there. After hearing a few of them, I started to feel pretty good about my own noise!

Anyway, with regard to the temperature, I sure would like to know EXACTLY what my temperature is. Enough of this 4 bar, 6 bar, 8 bar nonsense!

Has anyone installed a REAL temperature gauge and, if so, which unit did you use? Guess I could do a search here (I have done many), but not on this topic. (Plus, I'm at work. Shhhhhhh).

Thanks again for all the input, guys. Extremely helpful forum and not taken for granted. At least not by me!

[admin]

The last GL1200 I worked where the complaint was top end clatter turned out to be low oil pressure. The clatter would come and go so finally I put an oil pressure gauge on the bike and discovered that there was no oil pressure at less than 2000 rpm and even further up the rpm range the oil pressure only rose to 15 psi. This bike had a mild, but, constant indicator of water/anti freeze in the overflow tank but the owner refused to acknowledge that as a problem no matter how much I insisted how serious the issue was. I now have the short block of that engine in my garage, after I replaced the engine in this bike, and upon inspection I can clearly see that the water pump is thouroughly shot because the impeller is wearing into the aluminum pump housing. When I tear this short block down for inspection, when I get time, I am certain that I will find wiped out crankshaft bearings because anti freeze in the oil eats the babbitt off the bearings and clearances increase causing a severe loss in oil pressure. I'm not trying to scare you, but, if you hear top end clatter you should use an oil pressure gauge to determine oil pressure and see if it's in the ballpark. It is possible that a previous owner did not change a leaking waterpump when needed and the crankshaft bearings may have suffered causing an oil pressure drop to the top end or perhaps the oil pressure is good and the clatter is only due to oil blockage in the valve train or perhaps from improper rocker arm shim adjustment that is easily adjusted or maybe there is air in one of the "lifters" and it needs to be removed and manually bled. Either way, when you hear mechanical noises in any engine you should always determine if oil pressure is correct or not as a first test. Note: oil pumps are no longer available for the GL1200 engine, but, a good machinist can often rebuild an oil pump to near new specs by good machining. Good luck and please us know what you find out.

[bs175dths]

To get back onto my particular issue - I do not have a detonation problem. This is top-end valvetrain noise. And I can assure you, I do not have appreciable carbon build-up. I do NOT baby this machine. I RIDE it. I don't beat it, but it is not one of those that stays below 4500RPM. I have always been more performance oriented - and a long list of bikes and cars over the years would attest to that. (I won't bore you with that. But, NONE of them were MOPAR....or Harley)

So, I am less worried about the 'clatter' now that I have more or less isolated its source. Also, thanks to someone in this thread, I went to youtube and listened to some of the poor GL1200's on there. After hearing a few of them, I started to feel pretty good about my own noise!

Anyway, with regard to the temperature, I sure would like to know EXACTLY what my temperature is. Enough of this 4 bar, 6 bar, 8 bar nonsense!

Has anyone installed a REAL temperature gauge and, if so, which unit did you use? Guess I could do a search here (I have done many), but not on this topic. (Plus, I'm at work. Shhhhhhh).

Thanks again for all the input, guys. Extremely helpful forum and not taken for granted. At least not by me!

Btw – I am glad the youtube suggestion gives you peace of mind.
I don’t know who I got this from, but I have a test procedure for testing the operation of the GL thermostat from someone on this forum (thanks to whoever you are)
And with it came this chart describing the location of the needle (analog) or number of bars (digital?) and the relative temperature of the coolant.
1 bar – 40 C (104 F)
2 bars – 50C (122 F)
3 bars -60 C (140 F)
4 bars -70 C (158 F)
5 bars -85C (185 F)
6 bars -95C (203 F)
7 bars -105C (221 F)
8 bars – 115C (239 F)
9 bars – 120C (248 F)

I hope this helps.

Given the miles on my new (used) GL prompted me to want to listen to other GL's of similar vintage/miles. Once my ear was 'tuned' I was satisfied that my engine chatter was somewhat normal. I am still working on reducing the volume of the engines conversation but I think it is a factor of miles and period of non-use which has made her a talker. I believe the changing of oil, Seafoam, MMO and large doses of riding will slowly cure her of as much chatter as the design will permit.
Good Luck and keep us updated.

(btw - I am keeping the name for the time being)

-Ride On ~O)

[desertrefugee]

Well guys, not to be a pain over this, but this 'wing has me worried - and I have yet to put my finger on the problem.

I am not currently too worried about the top end clatter - and for now am assuming decent oil pressure. Especially since the clatter seems quite a bit more pronounced on the right side. Also, keep in mind that I do have a pretty discerning ear. A new rider or less experienced "wrench" probably wouldn't notice. (Not trying to puff myself up, just being forthright).

But, the hot running has me worried. I pulled the thermostat and tested it. It's opening around 188 or so. OK for now, I suspect. Probably not the culprit. The water pump seems solid as a rock. Spins as it should. Hoses are not kinked or pinched after the Poorboy installation. I really don't think I have a head gasket problem, but have yet to rule it out. Other than unexplained hot running, I have no other indicators to that problem. (That I know of).

Today, I took a 40 mile freeway trip in 75 degree weather. Very gradually, the bike worked itself up to 6 bars. Got off the freeway and had some surface street riding to the destination and gauge went to 7 bars. No boil over, running well, but the "clatter" always seems just a little louder when it gets hot - and it's not a constant chatter. Seems to come and go.

Did my business and headed back. Bike had cooled but quickly went back to 6 bars on the freeway and then hit 7 bars about 5 miles before my exit.

I have seen the table above with temperature ranges, but that's assuming a calibrated sensor. What if mine is out of whack and the danged thing really isn't running as hot as I think it is? I am seriously considering plumbing an aftermarket auto gauge onto this thing so I can quit guessing.

Has anyone done that? I actually have an old set of 2" Autometer gauges. I could pop out the temp gauge and give it a go. I might be able to rig something on the lower hose for ease of access...

[neoracer]

not to confuse you but the bar readings are from honda new specs per se and i find it hard to beleive that my bike is riding 1000's of miles at 140 deg,i just know that since i have had my aspy the normal reading is 2 bars, 3 if in the summer riding 70mph on a hot road

if you had an infrared temp gun you could measure right at radiator where the input from bike to radiator is and get a decent idea of the temp,you might have a clogged radiator too,which would make cooling difficult,might be radiator is only 50% functional

[firstwing85]

Hello, just a quick note,
I rode Vanna to work and back 4 days last week with outside temp at about 10c (50f) to work and 3c (36f) coming home
and my temp ran at about 4 bars while going down the highway.
last summer I did see it at 5 bars but the only time I have seen mine at 6 bars is when it was
sitting idling for an extended time and dropped down as soon as I would ride a bit..

[desertrefugee]

I guess I need to quit fooling myself. Regardless of what my plugs are telling me, I have a head gasket problem. I don't think there's any denying it.

Picture it. Phoenix, Arizona. Ambient temperature of 80F or ~30C with a dewpoint of about 3 degrees. Dry, dry, dry. Bike at six bars after homebound commute. I shut it off, let it sit a minute or so and fire it back up. Sweetish smelling moisture (fog) out the pipes for about 10 seconds. That shouldn't normally happen in dry air with a hot motor.

Agreed?

[spongebob]

Sounds similar to mine, tests prooved inconclusive as it only really leaked under riding conditions. I'm not sure whether my home made test of sealing a plastic bag over the overflow pipe and seeing it inflate with hard riding is valid, but with the heads off, one cylinder has signs of coolant washing and the radiator would bubble when hot and revved hard.

[Burnout]

Nobody has yet mentioned if the electric fan is working properly? Has the radiator been flushed out externally and internally? Blockage? Compression test? Cylinder leak down test? Everything else you say seems to check out good. Check these before you condem anything else.

The only thing left would be a "seeping" head gasket. It's not fully blown yet, but it's about to. You just got the tell tale sign..... :twisted:

[wingandaprayer]

My vote coolant in combustion chamber.

[desertrefugee]

Nobody has yet mentioned if the electric fan is working properly? Has the radiator been flushed out externally and internally? Blockage? Compression test? Cylinder leak down test? Everything else you say seems to check out good... :twisted:

Thanks for the voice of reason, but the fan works fine and the radiator is pristine. I had a good look at it last month doing the alternator conversion. And though the bike runs quite well, I have not done a compression test - although I'm not sure how low compression would affect heat transfer in the cooling system. If I had a significant delta between cylinders, it wouldn't run as well as it does.

I'm not anxious to pull the heads, but am beginning to sense a little inevitability here. And additional expense. I just dropped $500 between Poorboy upgrade and new Odyssey.

Sheesh.