SMOKE SMOKE SMOKE

[ditchweed]

so finally got the G5 running today for the first time in 40 years! was a lot of sweating and relentless kicking to get the timing and carb in the right place to get it started, that and the battery going flat half way through, but got it going and starting more than once so thats good, however it is also spitting out a lot of smoke and oil from the exhaust, so somehow oil is getting into the cylinder. any suggestions for how this might be happening would be appreciated, happy to have it running but aware i might have to back track a bit before its a possibility to go for a ride, so close and yet so far.

[Ozmadman]

Too much oil getting down the inlet valve, either because of wear or/and the small screw in the rear Rh side of the cylinder head that restricted the oil flow down the guide is open too much. Undo the locknut, screw it right in and then undo it the smallest amount like a 1/16th of a turn and then do the locknut up. If not then worn rings and/or bore

[ditchweed]

thanks paul was wondering what that did from memory its quite far out.

[ditchweed]

the thing i didn't notice was it is also broken, one side of the screw is missing which means i can't adjust it at all. tightened the tappets up so there is no play there and it started 3rd kick which is a lot better than yesterday. have attached a picture of what it looked like inside looks like a lot of oil to me but this is my first 4 stroke so not much to judge against. any input welcome. before i tear the whole things down again. if its the bore does that mean finding a new cylinder from some where to replace it?
Thank you

[Rangy65]

i would just go for the screw they are very sensitive so only needs the slightest of a turn from tight. You will see an oil puddle thats quite normal.

The part is avalable from the spares dept part number 010643 its the same as from a heavy weight.

Cheers
Steve

[alanengineer]

yes, new screw. At least you have something to hold on too to get the screw out.
Best of luck. And I have learnt something too.

[Ozmadman]

As has been said already, that oil is quite normal because it should be there to feed the rockers and find it's way to lubricate the valve stems(that's why it is smoking too much if the stems are worn as there are no valve stem seals used on this bike) I would worry if there wasn't any there. Any excess will drain back down the pushrod openings, lubricate the cam and followers and back to the sump. Make sure when running that you have oil feed to the rockers themselves , it comes out of two small drilling's behind each rocker arm, see short video of mine running.

[ditchweed]

yeah there is oil getting to the rockers can see it dripping down onto them, going to open it all up again and check the piston rings and valve guides, any tips on replacing the valve guides? also not sure if the cylinder has been rebored, does anyone know the measurements for the original and rebored cylinder and piston so i can make sure i get the right rings, theres only 26,000 miles on the clock but not sure what the last owner id.

[Ozmadman]

yeah there is oil getting to the rockers can see it dripping down onto them, going to open it all up again and check the piston rings and valve guides, any tips on replacing the valve guides? also not sure if the cylinder has been rebored, does anyone know the measurements for the original and rebored cylinder and piston so i can make sure i get the right rings, theres only 26,000 miles on the clock but not sure what the last owner id.

go to here, you can get all the manuals you need

http://archives.jampot.dk/book/Workshop_manuals/

Pick the 57-64 manuals (but make sure you are on the lightweight sections when checking data as these include other models as well) mine is bored out to +0.040"
Pistons for the 350 are hard to get try here as your best bet even though they are in OZ, unless anyone else has any other options

http://www.jp.com.au/JPPistons.html

[Rangy65]

Hello Mate i used a JP piston from http://www.fwthornton.co.uk/ they did have UK stock, the piston comes complete with rings but was £125 delivery was very fast.

Some people moan about the JP pistons apparently they are too heavy - i have had no problem with mine whatsoever and my G5 runs pretty smoothly.

Cheers

Steve