Fuller & Johnson Rejuvenation

Peter Rooke continues bringing this 1-1/2 HP Fuller & Johnson back to life with piston and cylinder head repairs – Part 2 of 4

| June/July 2014

This is the second in a four part series on Peter Rooke’s restoration of a 1917 Fuller & Johnson 1-1/2 HP Model N. Read part 1, part 3 and part 4 for the full restoration process.

When I removed the piston and connecting rod they were covered in carbon, so I gave them a good soaking in kerosene before trying to remove the piston rings. Once the rings were free, I eased them off one by one by sliding three pieces of shim stock under them to lift them out of their grooves. As soon as I removed the piston rings, I cleaned up the grooves and it was immediately apparent there were steps in each groove, either from wear or a poor tidying job on the lathe.

One thing was clear when the piston was removed: Someone had fixed a bolt through the middle of the piston, with a nut and washer on the inside, but why? Even more of a problem was the crack in the head of the piston, which appeared to be slightly dished. Had a valve come free and been pushed back into the combustion chamber, jamming against the piston?

There appeared to be some wear on the sides of the piston, so before anything else was done I took a series of measurements of the cleaned piston.

First, I checked the piston diameter and it was soon clear that there had been uneven wear down one side of the piston: The top two lands were worn 0.006-inch more on one side. Wear was also excessive, being 0.032-inch less than bore diameter at one point. I also checked the piston ring grooves using a feeler gauge and a piece of square high-speed steel known to be accurate at 0.250 inches wide. The top ring groove was between 0.022-inch and 0.043-inch oversize and the other grooves were larger than 0.012-inch.

Taking into account the damage to the crown and the wear to both the piston and the bore, I decided a new oversize piston would be the ideal solution, but the chances of finding one over here in England is nonexistent.


Gas Engine Magazine A_M 16Gas Engine Magazine is your best source for tractor and stationary gas engine information.  Subscribe and connect with more than 23,000 other gas engine collectors and build your knowledge, share your passion and search for parts, in the publication written by and for gas engine enthusiasts! Gas Engine Magazine brings you: restoration stories, company histories, and technical advice. Plus our Flywheel Forum column helps answer your engine inquiries!

Be sure to take advantage of the Square Deal Subscription Program.

  • No Missed Issues.

  • No Renewal Notices.

  • No Additional Cost.

The Square Deal Subscription Program is designed as a paperless transaction with automatic renewals at a preferred low rate.   With advanced electronic notification, a 100% satisfaction guarantee and an easy opt-out plan, the Square Deal Subscription Program is the best value, risk free, eco-friendliest way to subscribe.

Facebook YouTube


Copyright 2018, All Rights Reserved
Ogden Publications, Inc., 1503 SW 42nd St., Topeka, Kansas 66609-1265