650D1 vs 650D1A

OK, i've searched all over, including this site, and can't find what the difference is between a 1978 KZ650D1 and a 1978 KZ650D1A?? Does anyone know off the top of their head?

Off the top of my head I'd say the D1 is a 49 state model and the D1-A is for California. I'm not 100% on that but I think that is correct.

The Gringo wrote:

Off the top of my head I'd say the D1 is a 49 state model and the D1-A is for California. I'm not 100% on that but I think that is correct.

i'll do a slight variation of the same theme.

i believe the EPA federal emissions laws came in half way thru 1978, so the the D1 is the 50 state pre-emissions bike, and the D1A is the 50 state post-emissions bike.

assuming this is true, the D1A model would have leaner tuned carbs and air injection into the exhaust manifold.

just some educated guesses....:dry:

I have a D1A, and no emissions related air lines off the cylinder head or tied to exhaust anything; my bike is stock (non-fooled with).

The only emission hose on it is the one that runs from the top of the cases to the bottom of the air box.

Maybe the difference is advance curve or base timing.

Or gearing.

Or something cosmetic.

I think as aleady summed up is simply the D1A is the late 1978 production, and the D1 is early. Probably was the emissions laws as that was when the EPA was really starting to fool with motorcycles. I don't think any real difference other than carb tuning between D1 and D1A. Of course 1979 D2 started the emissions valves on the top of the valvecover.

OK, I did it the hard way and went through all of the parts to see what's different. As mentioned, the D2 is quite different and includes all of the emissions stuff. As far as the D1 vs. D1A, the only difference I see is the carb assy and various exhaust parts, including the muffler. I'm not sure if it's a later model or just the CA model, but it does seem to be emissions related. We need to find some frame number ranges for each model and figure out when they were made. For some reason, Zedder doesn't cover the 650 at all:blink: :S

KaZooCruiser wrote:

I have a D1A, and no emissions related air lines off the cylinder head or tied to exhaust anything; my bike is stock (non-fooled with). The only emission hose on it is the one that runs from the top of the cases to the bottom of the air box. Maybe the difference is advance curve or base timing. Or gearing. Or something cosmetic.

Uncertain whether this matters, but which pilot adjustment in carb -- air screw or mixture screw?

The A is the California spec model.

With most CA variants, the changes are usually limited to jetting/carburation differences - with some models having exhaust / emission variantions (and of course all the relavent CA emissions decals).

There are numerous mid year changes in 78 - with some models like the KZ1000 having as many as 6 different variantions of carbs / carb setups (and they are just the ones Kawasaki acknowledges - there seem to be some other needle jet/needle combinations not shown on the microfiche).

Post edited by: Jeff.Saunders, at: 2007/09/10 21:26

Jeff.Saunders wrote:

The A is the California spec model.

With most CA variants, the changes are usually limited to jetting/carburation differences - with some models having exhaust / emission variantions (and of course all the relavent CA emissions decals).

There are numerous mid year changes in 78 - with some models like the KZ1000 having as many as 6 different variantions of carbs / carb setups (and they are just the ones Kawasaki acknowledges - there seem to be some other needle jet/needle combinations not shown on the microfiche).<br><br>Post edited by: Jeff.Saunders, at: 2007/09/10 21:26

That's very interesting. I was wondering if the 900's or 1000's had any differences within the same year. I guess the difference is that only the 650 got a different model designation. Then again, the 1000's have 2 variations that I've seen: KZ1000 A3 and KZ1000A3A for example. I guess the A3A is the CA model??

I'm still not 100% on this subject but I know for sure I have a late 1978 KZ650B2A and it was not a California model. It was bought right here in Colorado, so I'd assume the SR was the same thing basically. My 1978 B2 was made 9/77, the 78 B2A 6/78. I'm sure California did not wait until 6/78 late run to get their 1978 model bikes, so I would think B2 and D1 KZ650s were also sold in CA, and no way Kawasaki is going to go to the trouble of making an entire late 1978 production just for the CA market. Too much work and money for just one state. So I still say the A was just a late production for the entire USA market, but who am I to say. Jeff knows a lot more than me, I'll have to admit, but A models just for California does not make real logical sense to me at least.

Post edited by: RonKZ650, at: 2007/09/10 22:05

D1 from my understanding were the 78 SR produced in the calender year of 77 (Serial numbers which would not have exceeded probably 4000 or so) and had an on/off switch for the headlight. D1A were the 78 SR's which were manufactured in 1978. In 78 Feds mandated that the headlight must stay on, so the on/off switch was removed. However, there is still a spot on the handlebar switch casing where the on/off switch would go. Even on Abbie's LTD, there is the spot where the on/off switch would go, if it had one.

Again, this is to the best of my knowledge, so there is room for error.

Also, the emissions control (reed valves in the top of the cam cover) didn't start until 1979. Also, the 79 had the 4 pipe plugs in the header pipes. I've been told that they were used to simply drain moisture. I've also been told that they were used to hook up exhaust sampling equipment. I don't know about internal carb emission control, like Jeff had mentioned though.

Post edited by: Mellvis, at: 2007/09/10 22:15

From the back cover of my FSM:

KZ650-D1A -- KZ650D-003440~
KZ650-D2 -- KZ650D-010601~

Obviously there are very few true D1 models out there, only 3440 at most.