Forum

[TimG]

Hi all
Have got my 2006 Classic 500 (iron barrel) in with my local dealer (from whom I bought it and who I trust implicitly) for some work. He has lifted the head and found that when looking down the bore he can see practically the full width of the rings all the way round - fairly good indicator of a worn bore. Now the bike has only 21,250 (hard commuting) miles on it, isn't smoking and has good compression. My question is - how usual is this on Enfields? I would have thought just over 21k miles a bit soon for a rebore. Again, I'm not questioning my dealer's knowledge and expertise, as everything he has done on my Bullet has been A1. I have occasionally let the oil get a bit low, but never less than 75% full. I haven't changed it as often as I should have - could this have anything to do with it? I'm just curious, as I have taken dealer's advice and am going for the rebore, as it looks very much as if it will desperately need it within a few more k miles if I don't...

Cheers

TimG

[Les H]

Didn't your dealer measure the bore? You have to remember the top of a cold piston is much smaller than the bore to allow a great deal of piston expansion when running perhaps enough expansion to nearly fill the bore and hide the rings. Tell him to measure the bore ACCURATELY. 20,000 miles will have caused some where but the Bullet has a good air filter and might well do 10K or more mileage. I would at least fit new rings if you don't need a rebore though, (very slightly glaze bust the bore)

[Les H]

TYPO: 20,000 miles will have caused some WEAR...etc.etc.

[TimG]

Hi Les

When I last spoke to the dealer he hadn't had time to measure the bore, but he is firmly of the opinion that measuring will show that it needs an oversize...am still waiting for result of that. Maybe I should have waited a bit before posting!

Cheers

TimG

[Beezabryan]

Why did he remove the head? You do not appear to have any problem so why did he take it off? Someone who gives a firm opinion without bothering to measure does not fill me with confidence. The guy might be a decent servicer but he is not a good engineer more like a chancer.... Something not right in the state of denmark.... I have serious misgivings, 20.000 miles is bugger all,,,,,,,,,,,,My 2 drachma

[Presto]

Whether or not it needs a rebore Tim, you can be quite sure that the wear (if any) will not be because the oil level dropped to about 75% full. The Bullet may be safely run with the oil level on the dip stick between the lower and mid mark. In fact it's preferable to run at that level - to avoid excessive amounts of oil being blown thro the breathers and to avoid wet-sumping.

[trevorch]

I suppose 30,000km would be about right to check the top end and do a decoke, but if she is not smoking, good compression and if the bore measurement is within spec. I would politely tell him no thank you. Please decoke, change the rings and check the rockers for wear, otherwise leave well alone. Not a warranty issue. Cheers TrevorCH

[Presto]

Hi Trevor - do we still de-coke engines? I'd not thought that was necessary with modern fuels and oils. I maybe wrong!
Cheers.

[TimG]

OK guys, my fault, should have provided a bit more context...the reason the dealer took the head off is that I asked him to in order to investigate a persistent oil leak at the head joint (the classic pushrod area). The leak has been getting worse, wasn't sure if it might be a warped head, I haven't got the facilities to fix that if so. In fact he found that the head was perfectly OK, but also found a defective head gasket, so he will be replacing it with our host's excellent composite one. In his defence he has never done anything I have not asked him to. I also asked him to report on anything potentially dodgy he found while lifting the head, which he has done. He will be measuring the bore to check his visual first impressions. Bit of a bummer re the rebore, but would rather have it done now rather than have to take the bike off the road (again) a few thousand miles later...

Cheers

TimG

[TimG]

NB...I am also taking the opportunity of replacing the standard piston with a European-made 9:1 item...will give a bit extra shove up those hills!

Cheers

TimG