Upgraded and Struggling A3

Hello all,

I finally got my A3 running, well sort of. I put a new set of STD rings on the Piston, new top-end gaskets, and honed the Cylinder to smooth out a little soft seize because of a previous air leak and running 56 Jet in my 15.15 with Bullet Pipe. My old 14.12 was shot (somebody used wood screws on the float bowl) so that lead me to buy the new 15.15 Dell...and while I was at it, a new Techo Bullet Pipe.

And so the problems began.

So I eliminated the common airleaks and the Engine idles and seems to run good. I have tried 68, 64, and 62 jets in the carb. The 64 seems to have the best results but only goes about 35 mph with the black Delorto airfilter cover on the carb. If I pull the cover off it will do close to 40 mph but struggles. Plug chops show very light brown. The 68 Jet runs like crap and yields 25 mph w/o aifilter cover. The 62 Jet seems lean and doesn't get up to speed either. SO I use the 64 as of now. My only question is that shouldn't I be atleast to 40 mph or so with these performance parts, I mean I'm lucky to squeeze

Re: Upgraded and Struggling A3

ez da snow man !! /

did you do any porting ? if not you should, that will gain much performance..

Re: Upgraded and Struggling A3

I opened up the intake manifold and matched the intake port and I polished up the exhaust port and slightly lowered it. Nothing crazy.

But seriously this thing sucks. It gets up to about 30 mph and revs like its full out. If I'm lucky I get it to 35 mph. Every time I do a plug chop "steam" comes out from the plug hole. My jets are 56. 60. 62. 64. 68:

The Run Down:

56: Seized it with air leak at the manifold and carb (FIXED NOW)

60: Haven't tried, too scared to seize after rebuild and expenses

62: Runs slow with and w/o the High Perf Airfilter Cover

64: Runs decent, 35 mph with Cover 40 mph w/o-Very Light Tan

68: Runs like crap maybe 25 mph with and w/o cover

Re: Upgraded and Struggling A3

sounds like you want a 64 with cover... after doing all that to the intake and exhaust have you done anything to the ignition system.. its probably in as bad of shape as the rest of the bike. Filing the points clean and re-timing it might be what you need.

Also, if its revving to piss, you might have a worn out second gear clutch.. but its highly unlikely on an A-3. they are very stout.

40 is about the best you can do on that cylinder without porting it. the intake and transfers are tiny tiny.

Re: Upgraded and Struggling A3

I have not fiddled with the ignition. It has OKAY spark somebody pulled apart a wire and I had to splice it. I've been looking all over to figure out how to set the timing on an A3. I want it set exact and Fred's Guide had me guessing. A3 manual didn't help either-Too much German.

Only other thing I can note is that after running it hard and taking out the plug, "steam" comes out the hole.

I'm also using a little bit small size of fuel line that is quite tight to get on. Don't know if that matters, but it flows. I ran down the road about a mile yesterday and it slowly died. Thought it seized and peddled home. Figured out the gas line was kinked a little and had to use a smaller size I had laying around, since there are not shops nearby.

Please tell me how I should go about and reset the timing.

Re: Upgraded and Struggling A3

i have been meaning to make a video of setting A3 timing, because it can be tricky. especially on the CEV ignition. the points are probably worn out or dirty, also, and you really should remove the flywheel and file them out a bit.

It is definitely worth investing in a puller if you cant get the flywheel off with the mallet trick. I've seen a few good a-3's completely ruined because people didn't use a puller and warped the flywheel.

Pull the flywheel, file between the points with a nail file, if you have some dielectric grease, or you can use two stroke oil, to lube the little felt pad that lubes the point cam follower. Put the flywheel back on. Put the piston at top dead center. The points should be open. Insert the feeler gauge, loosen the screw holding the points on, push the fixed point into the moving point, and push them both into the cam on the flywheel, so they are all snug together. Do that with one small flathead, and then tighten the points screw with a medium sized flathead. I have had good results on stock A-3's setting the points around .14-.15. Then you can play with the timing by loosening the stator plate screws (3) and twisting the stator plate for fine tuning. After setting the points, check to make sure the feeler gauge feels snug between the points when open, and make sure the points close when the piston is at BDC.

My mentor mechanic once told me '90% of carb problems are electrical'... i didnt understand what he meant until i started working on mopeds. I'm 99% sure your problem is from dirty points. Clean them up and put that 64 in with an air filter, you should be rippin.

Re: Upgraded and Struggling A3

I'd listen to what Graham says about the timing, but just in case you're dying for more info, you can read through this.

Re: Upgraded and Struggling A3

Thanks a lot mobyman, that helps me very much. Two questions:

Would a standard puller work? I think I have a little two armed puller around the shop... Also how to I get to TDC? Is there a mark on the flywheel?

Re: Upgraded and Struggling A3

the flywheel has 3 holes and you cant get most pullers in. there is info somewhere on doing the 'mallet trick' i think its one of the videos beemer did a couple years ago... cant remember the website its on, might be in the wiki somewhere, linda probably knows. if you have a good feel for machines and how hard you can hit sensitive parts with hammers and such, you have a pretty good chance of doing it right. there are also four tapped holes (M5x.8)around the perimeter, if you make a plate with 4 holes in it to correspond, and weld a nut and big bolt in the center, you can make your own puller, but the 'puch tomos' flywheel puller they sell on treats for like 20 bucks is totally worth it if you want to mod bikes, sometimes the hammer and homemade puller just dont get the job done... something about the A3 ignition cover is a faulty design... or maybe they just are more likely to get left out or something, or lost, but it seems like i find a lot with that cover missing and all the shit underneath rusty as hell.

if you cant get it, and want to bug me via email, i can probably talk my GF into videotaping a quick 'tomos a3 points how to' this saturday. i've got an A3 to assemble in the shop, so i'll have everything at hand, its just a matter of the degree people bug me vs. my ADD.

Re: Upgraded and Struggling A3

"This video?":http://youtube.com/watch?v=K8k8jDzbvXI (If yes, it's in the wiki in the flywheel article).

Funny, my Tomos was missing that cover too...

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