rmaynard 14,805 #1 Posted May 29, 2017 As I had mentioned in an earlier post, I got a couple of roughed up K91T's along with my barn find of the 401 and 551. So I decided to take them apart and see if I could get them running. The first one is a spec number 31107A. This engine, according to the seller, was the original engine on the 401. He threw a rod, and busted a hole in the block. So he had the block welded, got and .010 under rod, and had the crank turned. Soon after doing all that, the engine started making a clanging noise and stopped running. He replaced it with a newer K91T and never touched the first K91 again. So that is where my adventure began. I took it all apart, and found that the noise was coming from a broken camshaft. I replaced it, check the crank and rod to find virtually no wear, mic'd the cylinder (okay), and resurfaced the valves. I ball-honed the cylinder, and installed a new set of rings. Put it all back to together did a little painting, and started it today for the first time in approximately 40 years. Here is the results: Now its on to the next K91T k91t_run_video.mp4 14 Share this post Link to post Share on other sites
slammer302 2,154 #2 Posted May 29, 2017 Looks great 1 Share this post Link to post Share on other sites
squonk 38,567 #3 Posted May 29, 2017 That video reminds me of an episode in high school. We we're building karts and a friend of mine had a military surplus 11 HP Wisconsin. Hadn't run in like forever. We threw some gas and oil in it as it sat on the bench. Wound an clothesline around it and gave it a tug. It took off first try. Only problem was there was nothing holding the engine down. 5 Share this post Link to post Share on other sites
Ed Kennell 35,146 #4 Posted May 29, 2017 Take a bow Bob. She sounds happy to be alive again. 3 Share this post Link to post Share on other sites
953 nut 51,016 #5 Posted May 29, 2017 Need to have a new tag line, "the brake lining and K91 rebuilding guy"! 2 Share this post Link to post Share on other sites
WHX?? 46,404 #6 Posted May 30, 2017 I dunno Bob...sounds pretty rough.....I gotta RJ it might sound OK on tho....be right over to get it 2 Share this post Link to post Share on other sites
Walleye 28 #7 Posted June 1, 2017 So can I send you a box of parts to rebuild a K90 for me? The guy selling the Suburban it came with told me it needed a camshaft (which was included). No wonder.... both valves were seized badly. 1 Share this post Link to post Share on other sites
rmaynard 14,805 #8 Posted June 11, 2017 (edited) UPDATE... Just finished K91T #2 The rattling noise you may hear is coming from the WorkMate, not the engine, Here are both refreshed K91T's that I am bringing to the big show. Edited June 11, 2017 by rmaynard 5 Share this post Link to post Share on other sites
953 nut 51,016 #9 Posted June 11, 2017 1 hour ago, rmaynard said: Here are both refreshed K91T's that I am bringing to the big show. Two beautiful K91s! Where did you find parts? They are scarcer than hen's teeth. Share this post Link to post Share on other sites
rmaynard 14,805 #10 Posted June 11, 2017 9 minutes ago, 953 nut said: ...Where did you find parts? Gaskets - eBay Camshaft - eBay Rings - eBay Seals - eBay Recoil starter - Jake Kuhn Magneto - eBay, RS member RJ Hamner Points - eBay So with the exception of a few things, most everything can be found on eBay if you are persistent and patient. 2 Share this post Link to post Share on other sites