FMX head noises, i need some advice!

[metamorph67]

I want to stop all the clatter my FMX is making , has anyone out there changed cam chain or replaced tensioner, is it likely to be cam bearings that are causing all the noise or is the chain running to slack. Also Honda special tools, where is cheapest to buy them.

[switch]

I want to stop all the clatter my FMX is making , has anyone out there changed cam chain or replaced tensioner, is it likely to be cam bearings that are causing all the noise or is the chain running to slack. Also Honda special tools, where is cheapest to buy them.

If it's clatter from the engine, you're likely behind on servicing.

Cam chain has to be tensioned periodically and replaced if too worn. Valve clearence has to be checked every 5k miles or so. Either of these two components - if not properly maintained - will make the FMX sound like a Diesel.

The engine by DESIGN has it's own distinctive note. You can't make it not sound like it's supposed to.

[metamorph67]

Thanks Switch, the servicing is all up to scratch, i havent had the bike long so the damage was done by the previous and first owner, he may well of mistreated it, anyhow that still does not answer my needs, it shouldn't be making that much noise, i did the valve clearances, they were a bit slack, the noise gets quieter when the engine is fully hot, i really need to discuss with someone who has done the job before and can advise me of what is likely to be found damaged when i take it apart and what pitfalls i have to watch out for, what parts i am likely to need so that i can get organised and get the job done quickly - thanks again - mertamorph67

[switch]

Check the cam chain. If it's loose it might need replacing. That's the cause for some clicking noises on my 96 Dommie; but only when the engine is cold. Once warm, it's no issue.

There's also some clanking sounds that can come from the lower part of the engine - the crank case. Down there, a friend has a problem with the balancer shaft - the bike has been clanking like that for a full year now with no issues. The Honda guys here said that they'd have to take the entire engine apart and that's hours and hours of labor which means lots of $$$ - so my friend gave up and just rode the bike.


EDIT: Quick tip: change the oil and put in some good quality semi-synth oil.

[metamorph67]

Thanks for that Switch, yes it does calm down when the engine is Hot, it's a bit annoying as those kinds of sounds dominate my audible field, they somehow get where other sounds don't reach LOL Yes there is in addition a lower engine noise, just as i bring up the revs there is a heavy vibration as though something is out of balance, but like you say that would be madness to address! The problem is with these heads is to inspect the running gear you have to take of so much and then your in the thick of it, committed like a lamb to the slaughter, so you see it's a case of the bike will be of the road a couple of weeks unless i have everything i need ordered. Do you need special tools to break a link in the cam chain or is there a convenient breakable link? It is bloody annoying as it needs to be sorted, when i come to sell it that noise makes it sound tired! All the best - anyone else?

[AlanH]

Do you need special tools to break a link in the cam chain or is there a convenient breakable link?

The camchain is endless. You fit it by removing the clutch, looping it over the primary drive and feeding it up through the camchain tunnel.

How many miles has the bike done?

[switch]

The camchain is endless. You fit it by removing the clutch, looping it over the primary drive and feeding it up through the camchain tunnel.

How many miles has the bike done?

The question is how many miles without proper lubrication. I know a guy that wasted a dommie's engine innards by running it nearly dry for like 200 miles. Surprisingly enough, the engine didn't lock up despite severe damage to the piston and cylinder. As a sidenote this was due to a pinched hose and careless rider.

[AlanH]

The question is how many miles without proper lubrication. I know a guy that wasted a dommie's engine innards by running it nearly dry for like 200 miles.

Yes, you can easily kill a motor in 200 miles with improper lubrication - but it generally won't be the camchain that suffers. My question was aimed at eliminating the camchain as a possible source. If it's low mileage but still rattly, the chances are it's not the camchain.

A camchain needs the tiniest amount of splash lubrication and will not fail at low mileage due to low oil levels unless a cam journal partially seizes and stretches/snaps it or if the tensioner is not working correctly.

In my experience, cam followers are a far more likely culprit on these if the oil has not been kept topped up.

[switch]

Also, not sure about the UK, but in Europe, 'fixing' mileage is an illegal but common practice used to hide a vehicle's real age. No way in hell for a low-mileage FMX to rattle because of the chain... but if it's got 30k miles then it might be an issue.

I have my dommi for almost a year and have done close to 9k km (~6k miles) already, with two long trips planned this month. I think I'll top 10k miles for my first year with the bike.

[metamorph67]

Thanks AllenH, the bikes done 10K hard miliage in the hands of a youngster, i got the bike with a remus exhaust fitted so i couldn't hear the noise, now its back to standard(temporarily!) Right atleast i know how to get a new chain on, i,m not a complete novice but i,m not used to these decompression set ups, i think your right the problem lies with past lazy service engineers or missed service intervals (which is likely) but i think your spot on with the rocker arms (cam followers) back later!