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By 555
#6212
Hi All. I have been having problems over the last few years of sizing pistons. As I see it its either heat or lack of oil that is the problem. So i am going to change the bits in the carb so I run richer, and then get all the timing done and have the carb set up properly. Hopefully that should sort the getting to hot problem out. The next is the oil supply. It was using alot of oil, but no smoke or oil wheel so must have been spat out of the exhaust. I will get teh barrel honed and a new piston and rings, hopefully that should sort that. Next is the oil possible problem. What do I need? High capacity oil pump? What about the oil pump worm and spindle? Would I need it? And what about the Pressure relief valve kit? Again is it necessary.

So my shopping list

Barrel and piston
Head gasket
High capacity oil pump
Worm and spindle
Pressure relief kit

With getting the timing/mixture set up right, and the above have i covered all bases?

its a 2004 500cc 65 Bullet with 6000 miles on the clock. Amal carb and stubby exhaust.

All advice gratefully accepted
By 2cvandy
#57869
I'm sorry, I can't actually offer any useful advice, but wow! You must really like that bike? If I had those kind of problems on a bike with 6k on the clock I'd get rid of the damn thing and buy a Honda. Seriously, is this usual? If so, how the hell have Enfield kept selling bikes for so long? Good luck mate, sounds like you could use some,,,,,,,
By Tim NZ
#57871
With out knowledge of state of tune, make of pistons, how it was set up, and actually seeing the pistons one it would only be able to make a guess...


Can you post any pics of the dead pistons;front, rear, top, and from underneath?


Simply honing the barrel and fitting up a new piston is not always the recipe for success.


What piston are you using, and what are ALL of its dimensions? What is the actual bore size?


How do you run the bike in? (like it was stolen?)


Fitting High Output oil pumps will not magical solve any 'oiling' issues if oil passages are obstructed and disc seats are scored?


Randomly fitting larger jets than needed will 'wash' the bore and break down the oil, as well as foul the plug and coke up the head and piston...


By Gaz262
#57612
Another good thing to check if it's going through pistons & seizing regularly is the piston rings

Make sure they are in their correct slots & the right way up! I believe the one that controls the oil in the barrel has the word 'top' etched into its upper surface - Please note: This is NOT the top ring on the piston but the second one down (I think)...

Just my two-pennorth m'lud.
By papasmurf
#57611
Personally, when the engine is in bits I would check every oil way and pipe carrying oil is clear of obstruction, and has the correct size hole in it.
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By PeteF
#57608
If it's in standard tune, high capacity oil pumps and pressure relief valve are just a waste of money IMHO. I'd spend that on a decent forged piston.
I would also make dead sure your ignition timing is correct. Running a bit rich isn't a bad idea but don't overdo it. You really need to check the clearance on the new piston - if you're farming out the honing to a decent company they should be able to do that for you.
By 555
#57876
Thanks for all the replies. I'm not that savvy to measure and check measurements , more of a take it apart , clean it. If broken put a new bit on. I have been quoted £1500 for a strip down, check , honed barrel new piston and oils pumps. Seems high imcomparison to the value of the bike. So the options are do as good a job myself, get it done properly and pay ,
Fit another RE used engine if I can find one, or fit an alternative engine. Any one got any thoughts . I would like to fit a different engine if possible for a reasonable cost.
By Tim NZ
#57884
There is no more than 2 hours work to remove head & barrel etc, measure, hone, reassemble and have running again.


Two days work to strip the bike/motor fettle and reassemble...

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