Tomos Love

May 20, 2013

So nice having multiple running bikes now that the Grumpy Dumpies is in action. Thus I can tear things apart without having to worry whether or not I’ll be able to have things back together and running in time for the Casserollers weekly ride.

So I last night I felt like tinkering with the Tomos…

Toward the end of last year I couldn’t seem to get the Tomos to idle correctly, I suspected air leak and I didn’t really want to tear the engine apart since it was my only running moped at the time. This winter I made that leakdown tester and got rid of all my air leaks. Once things warmed up I retuned my carb since fixing all of the air leaks caused the engine to be running rich. I thought I had the problem solved, but sure enough it still wouldn’t idle for shit. Back to square one.

I figured I’d recheck the timing though I could have sworn that I’ve already double/triple checked it in the past. Since it has a puch polini kit on it I try to shoot for 1.2mm btdc. When I checked it it turns out that I was running just a hair btdc, like .2mm or something. No wondering it was running like crap, I’m surprised it idled at all. Reset the timing to 1.2mm.

While I was at it I figured I’d mess around with my clutches a bit so I drained the transmission and pulled the cover.  I’ve had a little bit of a rattling clanking sound for a while now so I set out to see if I could fix that problem as well. The first thing I noticed was that my sprag return springy thing was missing from the back of my intermediary gears, there were no remnants of it floating around in the transmission so I figured it was one of those deals where I had taken the engine apart and promptly forgot all about it. I stole one off of a spare A3 I’m rebuilding since it’s the same part. Lot’s of people run without them who knows how long I have, but I figured I’d replace it to see if it helped at all.

Tomos Sprag

Countershaft Return Spring or “Sprag”

So onto the clutches, from what I’ve read having loose/unbalanced clutches is the usual culprit when it comes to rattling/clanking sounds on a Tomos. Upon inspection my clutch padding has seen better days, looks like a rat has been nibbling on them. That’s going to have to wait to be fixed, I have a spare set of shoes that I’m going to have a brake shop reline so that’ll be dealt with then, but at this point I’ll chalk them up as ‘unbalanced’.

The next thing I did was pull the springs out of the clutches and put in some heavier ones. About a year ago I picked up a set of green(stockish), a set of blue(20lb), and a set of red(30lb) springs. I haven’t tried any of them out yet for the same reason mentioned above. I figured I’d go straight for the 30lb springs, go big or go home right?

Tomos 'red' 30lb spring

Tomos ‘red’ 30lb spring

Before installing the springs though on the first gear clutch there is a clawed discy looking thing that provides some tension to secure the clutch shoes tightly on the clutch assembly. I’m not sure of the actual name of the thing, but I have it circled in the image below.

Tomos Clutch Tensioner

Clutch Tensioner Thing

I watched a youtube video of someone placing shims underneath theirs to step their clutch from making clacking noises. I figured I’d skip the shims and just try bending the ‘teeth’ of the tensioner slightly so that the shoes fit a little bit more snuggly.

After that it was time to install the springs, what a pain. I used a combination of 3 vice grips and a bunch of flathead screwdrivers to get them on. Next time I do it I’m going to try and do a video as I think it might be pretty helpful.

Now I’ve gotten everything put back together time to refill the fluid. I’ve experimented with different fluids and viscosities and I’m kinda of in the camp of using something relatively light weight. Let the engine rev up faster by providing less resistance with the oil and use the springs and weight of the clutch shoes to control the engagement. So I’m running Mobile1 Ow-20W oil.

It was late and I didn’t want to piss off my neighbors last night so no time to test things out.

Hopefully no more clacking noises and easy idling are in my future…..