The 89 Craftsman big quad

I should have been taking pics of the engine swap and slight rebuild of the bolens!

Don't you have a thread for that?

I decided the seat was too high and in turn made it too tippy to drive on a side hill, so I decided to cut out the seat mount bracket and springs. I effectively lowered the seat 4", and it is much more stable. (aka I don't feel like I'm falling off the tractor) I also rigged up a direct throttle setup to give the $5 engine the abuse it deserves. I Bent the front axle, not enough that I have stopped driving it. I will start on a lift like Craftsman has after the build off, but will call it complete for now as we finish the build-off.

Got the qualification video up. I came up with a new name that is like a quad name with the displacement in it. Craftsman BQ 700.

the 700 is for the 696cc displacement of the twin.

Nifty paint color. At least you know the winch will always work dead battery or not.

Yeah, I've had electric winches and they sucked the battery dry way too quickly. One winch reel in would drain the battery so much it wouldn't be enough to make another pull.

Well I swapped out the bent front axle, so it drives good now. I swapped to the older 3 screw carburetor, (the old one was a 4 screw and I couldn't get it to idle). So I guess this one is finished! I will try to get you guys a vid of top speed and hopefully some romping. I have been really busy with college so I have been getting home when its dark so I can't take videos. But if I don't I guess its complete. And as you can see in the vid this tractor sort of runs on diesel, that was with the 4screw so I had to have the choke on all the time, but I ran it on diesel and it worked. I found the problem with the low compression, the valves are not adjusted right so the valves stay open when they are supposed to be closed. I need to grind down the valve stems so it works. We'll see if I make it!

Well I found out why the engine has been running like junk. I took both heads off and the carbon was THICK!  scraped/filed it off, and I used the file to "port" the heads. I found my valves were not seating. they had about a .006" gap from seating. so I ground them down so they seated all the way, and since I didn't have any head gaskets (one of the old ones was blown) so I used a file to flatten the surface and then I used silicone gasket maker to make a very thin seal. I put it back together, and with the 3 screw carb and the greatly increased compression it runs like a charm now.  The rings and pistons are worn, while I had it apart oil was running right from the crankcase and out from under the piston. (Just from running the oil splashed through, it wasn't over full) So they will need attention in the future. but for now the starter cannot turn it fast enough to start it, so I have to pull start it. (the cord keeps snapping if I'm not careful ) THIS BUILD THE BQ 700 IS COMPLETE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!      

Specs:
19hp briggs "turbo cool" with thin head gaskets and older twin II 3 screw carb, governor eliminated
foot throttle with high idle stop that you push in so it locks the engine at a slightly higher speed than idle (cruse control)
dual 2" exhaust
Spicer 5 speed transaxle
3.5" engine pulley
3" transaxle pulley
2000 lb manual winch (batteries hate me for some reason)
upgraded brakes
cut 15" front turf tires
18x9.5x8 rear ag tires at the moment
rebuilt front axle with pivot bolt tightened up so it doesn't tip as easy, with 10 degrees positive toe
bullet proofed old style steering box (no plastic parts, thanks to Stretch44875 for advise)
I did a gearing calculator and with 9:1 ratio in 5th I should get to 35 mph at around 4500 rpm
lowered seat for stability
key lime paint (hey my little brother picked it out for me)
removable rear rack
whighs about 425 lbs (my scales are all off. one says I am 200 and another 230)

Looks good! I know what you mean about batteries not liking you, I got the same problem. Good idea on the winch.

Thanks! dang mine is nothing compared to yours. but whatever. May the best build win!