05 RMZ 450 Compression, problems?...Please Help!

I just bought a 2005 Suzuki RMZ 450. It is usually hard to kick(seems kick start arm isnt right)but it does start after a few kicks. Once started it makes a pretty loud clanging noise. I've had a 05 Honda CRF 450 and it did the same thing but not nearly as loud. So im thinking either it needs a new top end or bottom end?

Can anyone tell me what I need to do to check whats wrong?

Also I checked the compression last night and its only at 120 PSI.. is that too low?

Please help!!! I am not mechanically inclined

Thanks for your help!

If you just bought it, it probably has an old piston in it. That may be the clanging noise you hear. (piston slap) 120 psi seems good to me. (i'm no expert though) I have an 06 with 120 psi but no noise when running. Does the noise get less or go away if you increase the rpms? Then I would say piston slap and time for a new one before it falls apart. While you have the top end apart you could check the crank too. Manual calls for 61 to 102 psi compression. Maybe high compression piston in our bikes? (I don't know what piston is in mine)

Edited by Tailender

Start with checking the valves. These first Suzuki 450's have really noisy valve trains in them. I've had two 06 RMZ 450's and the engines are freakin' loud!

The sound of the clanging is constant and does not change when I give it more throttle...

If the compression is high that is a good sighn and not bad right? If it is low then it would be time to change it?

I am embarrassed when asking this question but how do I check the valves?

Also I have noticed that fluid is leaking from the head.... possibly needs a new gasket. Would that alone be the cause of the loud clanging?

Thanks for all your help.... really appreciated!!!

Checking the valves is easy. Clean bike, remove tank, remove valve cover and plug wire, set timing at tdc and use feeler guage to check clearance. intake is .15mm to .20mm and exhaust is .17mm to .23mm

Fluid leaking is not good. What is it anti freeze or oil? New head gasket would be needed no matter which fluid it is.

These bikes run hot and are quite prone to cylinder warpage when ridden without coolant. That's no good! Check to see if your radiator is missing coolant and report back. Don't ride it bro, get her fixed first! Don't be shy either, we will do our best to help you!

You really need a manual too, it will help you check your valves and adjust them, and also adjust your cam chain tensioner. Don't be overwhelmed either, just read and follow along.

I just bought a manual and plan on checking the valves and cam chain this week when I have time. I havent been riding the 450 at all yet espically with the knocking noise and because I have a 07 RMZ-250 to rip on to keep me occupied.

The coolant level is at full. It looks to be oil that is dripping from the head. When I checked the gasket it looks to be in perfect condition.

I will check back in when i know the results.... Thanks everyone for your help!!!!

I just bought a manual and plan on checking the valves and cam chain this week when I have time. I havent been riding the 450 at all yet espically with the knocking noise and because I have a 07 RMZ-250 to rip on to keep me occupied.

The coolant level is at full. It looks to be oil that is dripping from the head. When I checked the gasket it looks to be in perfect condition.

I will check back in when i know the results.... Thanks everyone for your help!!!!

If it is oil, it may be leaking from the valve cover gasket. Then you are ok, just need to clean and reseal/replace the gasket.

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