Well I just went and looked at the cylinder. And you can clearly see were the rings are not touching the cylinder. So it is egg shaped. I think I am going to go with the Wesco 76.00mm that will be .060" overbore from the original of 74.50mm Is That Right? What is the gap to be at between the piston and the cylinder. another ? Can the oil injectors be rebuilt? Because after I get done rebuilding the top end and putting new bearings and seal in. I'm not going to have the money to buy a new one. Or even a used one. So If they cant be rebuild. I will just have to start mixing the gas and oil.

 

Have the cylinder measure to see exactly what oversize is needed before you buy another piston. If you go further than needed you just loose an extra bore down the road if ever needed.The injector is just a spray nozzle and tube from the oil pump leading into the carb that sprays oil into the gas/air mixture then into the engine. Nothing fancy about it. Main thing to check for is that you DON'T have the plastic oil pump drive gear when you take the pump out. If you do replace it with the metal updated one. Manual calls for between .0012 to .0026 piston to cylinder clearance. .012-.026 ring end gap.I know most people allow a little more on the forged Wiseco pistons on clearances,but imo I wouldn't go over .0026 as noted.

 

Well I just took the jug to the shop. They said that it has to go to 76.50mm because it is so egg shaped. That is the max it can go. He also said that the clearance should be around .005"-.010" on the new piston. I ordered the piston it should be here tomorrow. so when it gets here I will take it to the shop.

 

This guy is nuts if he thinks the piston to cylinder clearance should be this much!! .006 clearance is what's considered worn out..If that's what you'd have,then it's either time to have the cylinder sleeved or get a used one from ebay.

 

well see. That's what I thought. If you put a feller gauge on one side of the piston it should be .004" That way when you center the piston with the rings. You will have .002" all the way around the piston. when I take the new piston to him I will make sure he knows about the clearance's. Or I will take it some where else. And I have another jug that is standard. So If I have to ever re jug It I have a spare. He said it was egg shaped about .003 over the recommend tolerance.

 

Look back at the video towards the end. Shows how to measure clearance of the piston to cylinder with feeler gauges.

 

Well I just took the cylinder and the new piston to the machine shop. It clearly state's on the piston box .0030" Clearance. I made sure that he new that. And I told him I will be checking it when I get it home. He said He will cut It to .0030" And after I get It back and every thing is ok. I will be needing some information on the crank bearings. I still need to get the bearing off the crank. I have to figure out how to get the worm gear off. I don't have a bearing splitter. I might make one. What do you think?

 

Easier just to get a cheap 9 buck bearing separator. Will go behind the bearing to where most pullers can't and will remove the bearing and the worn drive gear at the same time after you heat the worn drive gear up.Plus you may find other uses for it later on. http://www.ebay.com/itm/New-Small-Bearing-Separator-Splitter-Puller-2-1-4-Remover-Separators-/321618588491?hash=item4ae1f6334b&item=321618588491&vxp=mtr Probably can find one at Harbor Freight,Northern Tools,etc.

 

well I just got the cylinder back from the shop. And It looks good. I checked it and the clearance is 3 thousands. And I got the bearings. The one on the stator side has to go on first because of the worm gear. But how would you recommend how to put the other bearings on. Should I put them on the crank first. Then freeze the crank and heat up the case. Or should I put them In the case. Should I heat the case up? Or press them in with a press? I have a 20 ton press. If I press them In. And I don't get them just right. It could shave some metal off of the case or bearing. If I heat the case the bearing should drop right in. Then heat up the center race. And the Crank should drop right Into those. As long as the crank is chilled. So what do you think? I would like your Input. I have to much money tied up In this to mess it up now.

 

On the double bearings I just shot a little heat on the center races to where they just slipped on the crank shaft(have a punch and hammer ready in case they don't slide on all the way),threw the crank shaft in the freezer,chewed the fat with the other guys for about 10 minutes, then heated the devil out of the left case half. Pulled the crank out of the freezer quickly and it usually dropped right in the case. Chewed the fat with the other guys again as the left case cooled or found something else to do for awhile. Used a good bead of Threebond 1104/1194 on the left case and quickly heated up the bearing area in the right case then tapped the cover on with a dead blow hammer.Torqued down the bolts and lower end was done except for the seals. Installed them when the cases were cold.