1983 510 4T

Thanks for the info guys... it is the end that sits on the valve tip...

More questions..... anyone know if there is a cross-over 2T to 4T for the big end bearing..?? I have the crank apart... the rod is OK, as is the pin.. but wondering if I should put a bearing in it now that I have it this far apart.. Anyone know if a 2T bearing fits..?/ 500 CR..??

Yes, I couldn't agree more ruwfo..but my question was ..does anyone know of a cross over from/to a 2T bearing..??

You can easily check all parts # on parts lists.
That's what I do when I have the same question that you.

Yes. Michel, and that would be good..but Hva...do not show the individual parts of the conrod assembly with individual part numbers... they did many years ago..but not anymore.. I would have thoght that the "original" concept of the 4T used a 500 CR bottom end....??.. anyway , will have to measure the crankpin and bearing cage width .. go from there. Andy at Hva in UK may be able to help..

so..measurements are.. bearing cage width 15.70mm, crank pin diam 28mm and con rod big end i.d. 35mm...... any one able to check a 2T big end bearing for a comparison..??

Aren't the # bearings named in parts lists ?

Not any more...they are shown in the exploded diagram.. and have a number ( eg..#6)..but aren't shown as an individual part..only a component of an assembly.. i.e. conrod assembly..

Anyway...looks like Andy at HVA in the UK has a bearing that matches... great info.. now I can replace the big end bearing without needing a crank pin / con rod also..

I've looked at 83 2str and 4 str parts lists for the crankshaft bearings.
2str left : 73 82 205 25
2str right: 73 83 205 40

4str left: 73 82 205 28
4str right: 73 83 205 40

Maybe my english isn't so good.. but I am talking about the big end bearing..not the crankshaft bearings.. I need the bearing that goes in the large end of the connecting rod...

LOL ! No your english is good, not mine . Sorry !
So, Big end is on the crankweight .

So..this where I am at with the engine......92mm Wiseco piston from Rik Smits.. Killblewhite valves and guides, new rocker shafts , rocker arm cam rollers and rocker shaft bushes, cam chain...cylinder being bored.. head being fettled... I note that the screen filter in the side of the cylinder is very dirty with garnet after the cylinder was (balsted) cleaned up.... is that screen supposed to be able to be removed..??.. Mine is stuck pretty good.... do I just wash it out..?? I note it is listed as a spare part, so I would think it shold be able to be removed..

Next question.. mine has a K&N air filter....can't find a listing for it on K&N anymore..... any suggestions..?? I am a bit gun shy about a foam filter..even with a screen...

Nothing wrong with using a foam filter with a backfire screen fitted. You can also remove the screen and use filter oil that is not flammable. They are available now days. Easiest is to keep the screen in my opinion.

The oil filter you describe can be removed and cleaned and/or replaced. How did it get garnet on it? Garnet should not be used anywhere near an engine...asking for trouble. I use paint stripper or else soda blasting. You have a major clean up job ahead if you me thinks.

I extinguished a filter fire on a BSA Goldstar at a classic scramble, it was it's first meeting after a full restoration, to say the owner was panicking was an understatement. I think he took notice of the regulations after that and bought a fire extinguisher!

Many bikes have caught fire at race meets. Most are fuel fires. Good maintenance and an understanding of the risks enables most people to build and maintain their bikes so it doesn't catch fire. Dusting an engine with a poor filter is another risk. Not too many dirt bikes run unoiled paper filters ... to my knowledge anyway. Don't know much about K&N filters but I assume off road buggies etc run them?

Not possible to find a 510 KN filter with all 510 owners in OZ ?

the maico 250/490 81 foam air filter fits well and is cheap and readily available. I have always used them. I bought a air filter from HVA recently to compare, and its a maico filter!! HA !
I have had a singed air filter, but itll only backfire if you hold the throttle open ( and it wont start anyway!) still I have a screen in there too for safety.
I don't trust the paper filter as cleaning is suspect but each unto their own.
If you are having trouble getting the screen filter out it may be because the cam chain has rubbed the ally deforming the chamber for the screen. I have had to dremel / flap wheel a cylinder oil holder back to shape, to allow the filter to slip in and out and open the area for more surface area =oil flow.
Taliesin racing has rod kits at reasonable prices