saw miller

After the leaking cylinder cylinder liner saga on my model 92 I finally had it running well with the 627 Amal carb. I rode the bike for a few days, but I was constantly having to adjust the air screw and idle screw. She pulled very strong. Soon the noise started. Sounded faintly like piston slap. The more I rode the worse it got. O boy, here we go again, I thought. I figured the bore was getting wrecked again. Pulled the head and all looked fine. Ran her some more and the engine sounded really rattly. Next I put my ear to the engine and the noise seemed to be coming from the carb. Sure enough it was the Amal. The slide was rattling around and making a terrible racket. With the air box off I could touch the slide with my finger and the rattling would stop. Off with the Amal. Received two carbs in the mail that Larry had tested for me. I was really looking forward to trying the 24 mikuni first. Installed the carb and it ran so fat that the bike looked like a mosquito fogger going up the driveway. Off with the 24, on with the 28. The 28 did the same thing. Sitting there, with oil running out of my freshly re packed mid box, I cannot figure why these carbs would run for Larry and not for me. Time for a phone call. Talked to Larry for awhile and we are both scratching our heads. There is an elephant in the room that we don't see, he says. Turns out that elephant was there all along, but he looks a lot like a can of vp 110 race gas. I run race gas. Larry runs pump gas. Moved the needle to the leanest clip setting and she runs perfect. Had no idea the needle setting and race gas would have that much of an effect on one eighth to mid throttle input. Tripp

Engraved on the case of one of my model 92s. Built by Jack Woodlee at P.E.C.O. Winchester TN. M 9200711. Owner Ernie Johnson. The two previous owners have no information on the engraving. I am sure there is a story behind it. Tripp

Installed the Amal and she really runs sweet. Looking forward to riding the bike in my next trial. Thanks again. Tripp

Lbhbul, aka Larry, saved me on this one!!!! His theory was that the cylinder liner had to be leaking air. As soon as the engine heated up it was sucking air between the liner and the jug. We are not sure why, but it is. Larry was kind enough to source me a new cylinder, Mahle piston, and rings. Heck, he even had it bored, fitted the rings, and shipped it to me. Over the past few weeks Larry and I have spent many an hour talking on the phone and I now consider him a great friend. Thank you Larry!!! The engine now runs beautifully using the carb off of my good bike. Not so good with the other carb. It has some kind of issue. Another chapter to this story begins. Thanks again for everyone's help. Tripp

John, Thank you. Tripp

Tried lapping again also used a little copper seal. Still leaking. I am beginning to think it is leaking around the liner. Going to try a another head next to make sure. Ibhbul, Where do I find your address. Tripp

Lapped the head multiple times. Guess I have had the head and barrel off and on six times today. Cannot get it to seal. Wow, quite an education this motor has been. She pulls like a freight train but will not behave. Have a trial in a couple of weeks, then Barber, and another. Time to put this one aside for awhile. Tripp

Bullylover Thanks for the tip. Will give it a try today. Tripp

Got the bottom end buttoned up. She holds pressure when cold. After warming up the head leaks terribly. This is a non gasket head. Re torqued multiple times. Throttle is still hanging. Guess it's getting air from the head. Any suggestions. Thanks, Tripp

Pulled the cylinder and put a little permatex moto seal on the case seams under the base gasket. The engine is holding pressure for a few minutes. Still leaking slightly at the rear seam. Getting a little leakage from the head also. Will try again tomorrow. Johnjsy, I put grease on my center case gasket. My Bultaco manual specifies grease. Tripp

Thanks everyone for your help. I finally seem to be getting somewhere. I built a pressure tester and block off plate for the exhaust and it worked great. Loosing air at the base of the cylinder at the case seams. I hope to work on it some today. Thanks again Tripp

Johnjsy Thanks for the information. That seems to be my best option for finding my problem. I will try to give it a shot this weekend and report back.

Johnjsy, Sounds like you have a fine collection of bulls. Thank you for the input. I removed and re sealed the intake yesterday and found no problem there. I wish I had lapped the cases as you described, warping could be the problem. This sherpa does not have the original cases, they are from an alpina. The center case gasket seemed to fit very well. I might t try spraying some carb cleaner around the engine today. I have not tried that since the rebuild.. Where did you pick up the Viton seals? Tripp from Appling Georgia with two Sherpas and a head ache.

Bodwheel, My engine has what I would call a spigot intake. It is connected to the carb with a short rubber hose. I will pull the intake again and give it a good look. There is air getting in somewhere. Tripp

Split the cases and rebuilt the bottom end. Had the crank done by Hugh's. New seals and bearings throughout. New rings etc. Runs great. Blip the throttle hard twice in neutral and she runs away. Swapped in the carb from the other sherpa and it does the same thing. What next? I am at a dead end. Tripp

Thank you! Great job! Tripp

Built a case separator afternoon. I attached it to the cases and heated them on a gas grill. The separator worked like a charm. The stator side of the crankshaft seems to have issues. I can easily slide the old and new bearing on and off the shaft without heating the bearing. In fact all three bearings stayed in the cases when I separated them. Great fit in the cases. Bad fit on the shafts. Seems that I need to have the crank looked at. May ship it to Hugh's. Tripp

Started breaking down the sherpa today. The stator side inner bearing race is spinning on the crank shaft. The plot thickens. The bottom end kit arrived from Hugh's . Time to heat the cases and see if they will separate. Tripp

My piston kit came wit two bearings and two spacers. Unfortunately when I put it together I left one in the box. Looking back,I remember thinking to myself that the bearing seemed really narrow. Guess I should consider myself lucky that more damage did not occur. Tripp

Not giving up yet. Guess that is why it ran so poorly. The rod and bore still look good. Will see about getting a new wrist pin and bearings. Might have to get another piston kit. Expensive mistake on my part. Tripp

Sometimes you dig your hole deeper. Sometimes you fill it up. Lately I am really good at digging. Tripp

Looks like I am going to have to eat s%+^t on this one. Should have been two bearings side by side on the small end. I only put one in. Ouch.

Broke down the engine today. Wrist pin totally shot. Suprised it did not lock up. Think I am done with this one. Parts bike. Tripp

Confirmed jet sizes with Hugh's Bultaco in New York yesterday. Everything carb wise seems to be perfect. I played around with the float height and clip positions. The engine just will not run correctly. I went ahead and ordered a bottom end kit from Hugh's. Maybe something is going on along the case seams. At least I will be starting from scratch. Tripp

Installed a new set of stator side crank seals. Swapped carb from the other bike. Same scenario. When I get the air screw set where it pulls good off the bottom, 1/2 turn on 1 carb and 1.1 turns on the other carb, she wants to run away. Rode the bike for an hour or so and it seems to be getting hotter than it should. Running 110 octane race fuel. 52 to 1 golden spectro. Sprayed carb cleaner around the intake and the base of the head again with the engine running an revving. No luck. This should not be this difficult. Attached is a picture of the stator side seal plate. Tripp