Model 45 Takeoffs

[teambrownracing]

I have a 1946 Harley Davidson Model 45 that I have owned for about 4 years. When I purchased the bike it was advertised as a "barn find" but when I got into it I discovered it had been restored in the mid 80's without much attention paid to the origin of the parts. Therefore, I did a cosmetic restoration and planned to ride it some for pleasure. I overhauled the transmission but did not do any engine work outside of adjustments, new carburetor, and new plugs. It starts and seems to run pretty good once you get going. But takeoffs are difficult and it is almost impossible to get it moving on any kind of a grade. When I say runs pretty good, I mean it will do 55 MPH without too much trouble and also does a reasonable job of getting me up a hill without downshifting. I have tried changing the output sprocket on the engine (27 vs 31 tooth). This doesn't seem to have much effect (when trying to takeoff on a grade the engine many times quits rather than take off). I am considering taking the top end apart to see if I have a carbon or valve problem. Are there any tests I should perform before taking it apart?
I have included a couple of pictures, one as I first saw the bike and one after my cosmetic restoration. I hope they come through on the post.Right Side View.jpgHarley.JPG

[Sargehere]

If it's that weak it's probably just tired. Best thing you can do is pull the top end down to the point of removing the heads and cylinders and learn what you have in there, anyway. Especially if it is a "put together" from parts. Your photos came through fine.
You'll find out a lot about your motor when you get the heads off: valve depth (how many times the valves have been ground, sinking the valves down in the cylinders, farther from the cylinder bore. Worn valve seats require a shortening of valve stems in Sidevalves to get enough adjustment. Check the comparative lengths of your valves to one another and put them back in the same holes.
You'll be able to see the condition of the cylinder bores with the pistons "down." and piston fit with them "up."
Then, when you pull up the cylinders, remember to stuff rags under them before pulling them up past the lowest ring; that keeps any possible broken rings from falling into the crankcase, requiring a complete disassembly even if you wouldn't otherwise need one.
piston-to-bore sloppiness will be very apparent with your fingertips across the piston tops.
When the cylinders are completely off, you'll get to feel the wrist pins & the big end bearings-to-connecting rod clearance (shouldn't be any apparent with the gentlest of touches, side to side or most apparent, up-down). Then you'll know what you have to do. Good luck!

[teambrownracing]

Thank you for the reply. It sounds like good advice. I have to clear a space in my shop to keep the parts organized but I'll get started in the next week or so. I will post some pictures when I get the top end apart.

[duffeycycles]

Do an air leak test before tear down

[T. Cotten]

Do an air leak test before tear down

Great idea!

http://virtualindian.org/11techleaktest.html

.....Cotten

[duffeycycles]

That too Cotton ,but I ment : top dead center[each cylinder] /tied down/high gear/ put air in cylinder & listen for leaks

http://www.caimag.com/forum/attachme...237852&thumb=1

[teambrownracing]

Thanks for the air leak test idea. I have 14mm to 18mm adaptor ordered which I hope will allow me to hook up my cylinder leak down test device. Should know by the weekend how this comes out.