'76 R 75/6 Dynatek III

I don't have my fuel tank right now and I am wondering if the Dynatek III electronic ignition module will fit under the tank just aft of the front brake master cylinder. It looks like that is what they intend but I figured I'd ask before I start feeding wires.

Thanks,

Chip

Chip -

My Dyna III module is mounted to the front cross brace on my /7 in between the two frame down tubes. I don't think you have that on your /6. But I'd be a little cautious about mounting that so hidden when little air flow. I don't know how hot they get, but since it's the "brain" of the system, I'd look for something a little more in the open. The obvious, and not so asthetic location, is on one of the forward frame down tubes.

I have a 75 R90/6 with the Dyna III the module is mount aft of the brake master cylinder under the frame tube.

Don

I kind of doubt that heat is going to be much of an issue. It has a fair amount of mass for the small sized wires going in and out so I don't think enough current can run through to cause a problem. I was hoping it would fit under the tank on top of the tube just behind the master cylinder. Sounds like the answer is, "No". I'll see if I can shove things around underneath the tube and make room. That will be a tight fit.

Thanks,

Chip

Chip, you might be right, but I don't know what's going on with inside the unit...could be nuclear reaction in there! I'll try and reach down and feel it the next time I'm riding...not! I might touch the body the next time I get back from a ride.

FWIW, I mounted a dynatech points booster behind the master cylinder under the frame tube, which is the same location, on my /7. I have measured the starter cover temperature using an IR thermometer and it has never exceeded 130-140 degrees, although I never measured the frame temperature - which is probably less. While there are lower temperature locations, the fuel tank (provided it has fuel) also acts to absorb heat. So, provided the master cylinder does not leak, it seems to me like a reasonable location.

I did a little checking on the Airheads mailing list, and most say they mounted the control until behind the coils at the back end of the backbone. Probably have to move the coils a bit forward. No mention of heat being an issue...so I guess I was off base there. I still like mine on the /7 cross brace...it's hidden enough and gets some cooling...if it's even needed. Plus, I didn't really have to futz with anything else, so I guess for me, that worked the best.

I've got mine mounted on the right frame loop just aft of the backbone. It's (barely) visible from the side between the tank and battery cover.

Back of the Backbone

A PO of my R75/6 mounted the Dyna III to the underside of the backbone, just forward of the tool well. For this to work, the band clamp was moved from the middle of the unit its end. When the unit died, I replaced it with a Dyna points booster mounted in the same place. When I acquired a second booster, I moved them both to the front of the bike, one on each down tube, figuring they would see more airflow in this location.

On my Motorsport and R90S it was mounted on the underside of the backbone behind the coils. I also moved the clamp and added another one.

My intent is to fasten the control module to the frame on the right side down tube behind the gas tank (under the seat). I want to run an auxiliary ground (10 guage) from the battery post to the frame where the coils mount. That appears to be a ground buss for much of the wiring and I am not comfortable with the battery cable to the transmission vent bolt being the only ground. I believe if I do that, I can use that ground buss on the frame as the ground for the Dynatek. They say not to ground to the frame but there will be a direct link to the engine case through the battery cable and the transmission vent bolt. Another option would be to use the black wire that connects the condenser to the coil in the same way (swap the spade connectors for ring connectors). That would be more direct. The rest of the hook up is confusing the way the directions are written but I think I have it figured out. I assume I just remove the condenser and keep it handy with the points? Make sense?

Thanks,

Chip

I believe my condensor is still mounted in the timing chest area of the bike...probably not a good idea since it is exposed to heat, etc. But certainly retain all of the original parts in case you need to switch back in an emergency.