Well, the previous owner replaced the coil with an internally grounded unit, and hooked the single wire from it to ground
I connected it properly to the harness, and it runs now.
Pictures:
Parts bike:
Runner:
| Vintage Dirt Bike Q & A https://vintagedirtbikeforums.alp-sys.com/ |
|
| 78 DT400 https://vintagedirtbikeforums.alp-sys.com/viewtopic.php?f=28&t=3122 |
Page 1 of 1 |
| Author: | 4x4_Welder [ Fri Oct 21, 2011 9:42 pm ] |
| Post subject: | 78 DT400 |
I just picked up a 78 Yamaha DT400 along with a parts bike. It's in pretty good shape, has great compression but no spark. I'm thinking the problem is the kill switch, but can't see how to isolate that. Can I just pull a connector at the CDI, or is there any other recommended way of ruling this out? As a more general question, is there anything to watch for on these bikes? I plan on using it mostly for commuting, but I'd like to run around in the woods every now and then too. |
|
| Author: | 4x4_Welder [ Sat Oct 22, 2011 3:00 pm ] |
| Post subject: | Re: 78 DT400 |
Well, the previous owner replaced the coil with an internally grounded unit, and hooked the single wire from it to ground I connected it properly to the harness, and it runs now. Pictures: Parts bike: Runner:
|
|
| Author: | 4x4_Welder [ Sat Oct 29, 2011 8:53 am ] |
| Post subject: | Re: 78 DT400 |
And I killed it- sort of. I was doing a quick test ride, and was almost back home when it started making odd noises and then died in the driveway. It would kick over with almost no compression, so I tore it down and found one of the rings folded on top of the piston. The cylinder is quite scored and may or may not be fixable. The parts bike has a good 86mm bore and piston, but no rings (?) so I'll get a ring set and a gasket set and be back to rideable just as it starts snowing. |
|
| Author: | Dave [ Wed Feb 08, 2012 7:57 pm ] |
| Post subject: | Re: 78 DT400 |
did you ever get it running again? |
|
| Author: | 4x4_Welder [ Sun Feb 19, 2012 12:05 am ] |
| Post subject: | Re: 78 DT400 |
Not yet. I had a bunch of sleds to get snow-ready, and I don't have any indoor workspace. I need to order a piston, rings and gasket set for it, then it'll be my commuter. I'll likely put modern d/s tires on it to help with mileage. It'll be running once the little snow we got is gone. |
|
| Author: | Swampdog [ Sat Apr 21, 2012 2:33 am ] |
| Post subject: | Re: 78 DT400 |
Try Yamaha enduro .com.Those are some great guy's with a wealth of information about anything Yamaha.Plenty of parts too. |
|
| Author: | dg1hellfire [ Mon May 21, 2012 6:41 pm ] |
| Post subject: | Re: 78 DT400 |
Be sure to inspect your brakes... old drum brakes like to delaminate if they get wet and dry wet and dry. In your case, hot cold wet dry who knows. I had a rear (thankfully) delam on me and locked my wheel right up. If this happens to your front wheel while commuting... well let's not think about that. As for tires, most enduro tires are 60/40 road/dirt or dirt/road. Long story short, if you have two sets of wheels, get road and off road tires. I put medium compound MX tires on my DT 250 and it hauls in the dirt but is super squirly on the road so I have a nice set of Kenda Enduros for road riding on a spare set of wheels. I look like a NASCAR pit member changing wheels in under 10mins... |
|
| Author: | 4x4_Welder [ Tue May 22, 2012 9:11 pm ] |
| Post subject: | Re: 78 DT400 |
Good to know about the brakes. Currently the bike is still sitting in Idaho while I get housing all set up here in WA. I got my Honda running decent so once that's registered I'll start using it as a commuter and work on the Yamaha once it's here. I'll probably play around with it a bit, like put a different reed setup and carb on it, maybe make a pipe, and put more street-oriented tires on. I have a Kenda K270 on my Honda and it seems decent in the little bit of riding that I've done on it, but I'll likely go with a modern d/s tire for the Yamaha. Something like a Shinko 700 or maybe a K761, I'll need to do a bit more research though. |
|
| Author: | Dave [ Thu Sep 27, 2012 4:39 pm ] |
| Post subject: | Re: 78 DT400 |
Swampdog wrote: Try Yamaha enduro .com.Those are some great guy's with a wealth of information about anything Yamaha.Plenty of parts too. yep! that place is the resource there for sure! |
|
| Page 1 of 1 | All times are UTC - 7 hours [ DST ] |
| Powered by phpBB® Forum Software © phpBB Group https://www.phpbb.com/ |
|