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Discussion Starter #1
Hey, I have a 1981 Yamaha SR-V 540. It runs, drives, and looks very good, but at idle it has a very dominant ticking sound that seems to come from the engine or the cooling fan. There is a video on google videos if you type in "Yamaha SRV" that comes up of a 1981 SRV idleing that has the same sound as mine. You can watch the video if you don't know what i'm talking about. If you rev it a little over the idle rpm's the sound goes away, but once the rpm's settle back down the sound returns. Does anyone know what this sound is and if it's normal or bad?

Thanks,

Tj
 

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I don't like the sound of that! It could be a number of things. Take a short piece of garden hose[3-4ft] hold one end to your ear and move the other end around to locate the source of the tick. Check the primary clutch first , then the cylinders, and finally around the cooling fan. Post what you find
 

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Thanks alot, I should be able to check it this week when it gets warmer here in southern Wisconsin. It runs awesome, I went trail riding with it the other day and it seemed quick and normal, it's just ticked since I bought it.
 

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I went out to the shop to try your suggestion, and the hose thing worked pretty well. I flipped the choke and it started after about the fourth pull, and it idled a little high (about 2300 rpm's) b/c I tried adjusting it last time I started it. Because it was idleing higher it was a little harder to pin-point the noise, It was still noticeable though. I decreased the idle speed to 1500 rpms (normal speed) and the noise returned to it's usual loudness, so I first checked the clutch and I couldn't hear the noise very clearly there. Then I checked around the left cylinder and the ticking noise could be clearly heard there. Finally I checked the cooling fan (on right side if sitting on the snowmobile) and right cylinder which was as equally noisy as the left cylinder! I still have no clue what this noise is and if it is damaging my awesome SR-V. Sorry about the long post, this noise is just bugging me alot! Thanks for the input!

TJ
 

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I was hoping the noise would be loudest around the cooling fan[loose in bearing]. The fact that it is obvious around the cylinders and has a pretty high frequency leads me to suspect what I first thought...maybe a broken piston skirt or a crankshaft/rod issue. I would definately get to the bottom of it before i rode it. I would take it to a local reliable shop so they can advise you, hopefully it won't be too serious!
 

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Discussion Starter #6
When I first bought this Sr-v I thought it was the fan b/c it runs way too well to be the piston skirt or rod. I've taken it on the trails twice now and both times it ran awesome. I could easily take-off quickly and get it going 70-80+ without any hesitation. It just seems way too normal for it to be something that serious. Wouldn't it not even be able to start and run if the problem IS that bad? Wouldn't it have already blown up? I guess you never know, you could totally be right! You probably know more than me about these. How would you get to the cooling fan bearing, is it just within the plastic fan? Could it be the belt that drives the fan also? Have you worked on any Sr-V's like mine?
 

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I have not worked on or owned an SRV[one of the few Yamahas I have'nt owned!] but I have owned + worked on Fan cooled sleds back in the day. Usually the fan is aluminum and spins on a shaft through a bearing. You would have to remove the engine cooling shroud to fully expose it. Tha plastic side cover may be fairly easily removed to inspect the fan. It makes sense it still could be the fan because if it is loose on the shaft/bearing it may be able to "rattle" against the Mag side cylinder.
 
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