[spike]

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[align=left]My name is Mike. I have a 86 gl1200 I bought a month ago and since then I guickley noticed that it sounds like all the pistons are rattling in it when I'm running down the road. it sat for four years in a barn and the man I bought it off of said it ran and road perfict when he quit ridding it. I had a bunch of work done on it including having the carbs redone and tuned. the rattle will quit when you let off of the gas and when you give it the gas. but when it planes out it will start rattling agin . the bike runs smooth and I can't feel any vibrations. I had a compession test done and the cylinders put out a 175 psi each. showing that the cylinders are good. the bike looks new and it only has 18,000 miles on it .any one that might know or have a idea on what it might be. please let me know. Thanks Mike[/align]

 

[Jason]

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Hi Mike. Without actually hearing the rattle it's hard to be too precise but I can give you some pointers;

A 1200 engine laying for years may develop sticky hydraulic valve lifters, rattly pistons at 18000 are hardly likely. You should run some engine flush through the engine for starters.

Second point is that the 1200 has a large Hyvochain in the back of the engine, it runs all around the genny, clutch & crankshaft. Just like in the GL1100, thi schain can rattle briefly when you put a load on the engine, eg giving it a fistful when in too high a gear and also on takeoff. This isn't a problem and shouldn't cause worry.

Third point is if the carbs are not balanced properly. This can cause the Hyvochain to rattle as it efffectively means the engine is under load when the carbs are out. I know you say you got the carbs "redone", did you have them balanced at the same time? If no it would be worth whilebetting this checked.

 

[Eamonn1200]

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I always know when my carbs are out of balance on my 1200, the engine makes a right racket! Goes away when I get them synched.

 

[spike]

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Hey! this is Mike. I'm new at this so bear with me. I appreciate all info. when I had the carbs redone I had them synchronze them to. now I have had to back the idle of because the engine started loosening up and also I noticed that chain I belive it was threw that timming hole plug on the back of the blockon top and also would that chain have any kind of hydrolic tensioner on it ? I just can't belive that it could be anything major. but that rattle what ever it is is kind of loud and also when your going down the road at about sixty and about 3.000 to 3.500 rpms. it has that constint rattle. is this confusing ? it is to me and also what kind of engine flush? Thanks Mike

 

[Renegade]

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Welcome Spike. I also have an 86 Aspencade that sat for about 4 years before I purchased it.. my bike makes a rattle, slapping noise when cold and running thru the gears until it warms up.. If it warms up prior to riding it, the noise never comes on. Only while cold.. 25,000 miles on the clock and a beautiful machine.. I was told it is the alternator drive shaft causing the problem from a GL1200 owner with the samesituation. Also, have the cam holders in the cylinder heads inspected for the proper centering. It's not a real big issue on 1986 models, but worth looking at before you pull the motor for an altenator shaft job. Has anyone taken an oil pressure test yet? Jason is usually on the money with problems like this one because the 1200 motorsare concidered "bullet proof".

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All Gave Some,, Some Gave All

 

[wingdawg101]

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These guys know alot better than i do, but I've flushed my engines for years (cars and bikes) with a quart of "Transmission Fluid", always worked good for me?! The Tranny fluid today has lots of cleaning agents in it! I change the oil, leave out a little less than a quart , put in the Tranny fluid and start it up , pick up the RPMS to around 2000 for 15 min. then change the oil again!

First check with Jason and some of the other guys on this site, they may have a better way to do it?

I have used "Wynns" Engine flush and it worked good too!

I think i use "Risolin" Engine flush once and liked it!

 

[spike]

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My bike doesn't start rattling to bad until the engine heats up . I think I'm going to try flushing it this week . also I haven't had the oil pressure checked yet. also I talked to the previous owner and he told me that the bike also had a diaphragm to bust in one of the carbs and caused it to lean out and get the exhaust pipe real hot but he said he didn't ride it until it was fixed . I just wonder if this could be rist pin knock I'm hearing from distorted piston ? the knock echoes threw the hole engine and it's so hard to try and pinpoint. Spike.

 

[Jason]

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A leaky carb could cause a bent conrod, but the knock would be there all the time and you would probably have a miss on that cylinder as well. The 1200 conrods are quite sturdy and I haven't heard of one bending from leaks like that. I'd go ahead and flush first. BTW, when the rattling starts does it go away if you pull th eclutch lever?

 

[spike]

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[align=left]Hi! Jason. the engine won't rattle just setting there at idle but you can rev it up and it will or when you run threw the gears it will rattle . know you can pull in on the clutch and rev it up and it will rattle . plus when I'm runing down the road and as I pull the clutch in to come to a stop I've felt a slite knock or peck threw the handle bars and foot pegs coming threw the engine. I know it's hard to trouble shoot with out hearing it first hand but these are some situations you can hear it. I had a guy tell me that honda had a recall on those bikes for clutch basket rattle because you could here it when the bike was being lugged around or when you reved the engine up fast but mine does it even running down the road. Thanks[/align]

 

[Goldwinger1984]

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I've heard quite a few folks comment about that rattling noise in the 1200's. My '84 1200 has a rattling noise as well. Mine seems to make that noise the most between 2800-3400 rpm at light-medium throttle settings. Full throttle, full load, no noise. I've often wondered if it could be rod or main bearings but typically these bikes run for hundreds of thousands of kilometers without any crank failures. I wonder, could it possibly be just the intake air noise coming from the airbox?

Vic

 

[FitzAl]

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ThegL1100 is even worse in that respect. The big chain rattles when you put a load on the engine. I've heard this happened even when they were new. A knocking sound is different though, that might have to be looked at more closely. Stickingtappets are common enough on the 1200 and they knock really loud.