KX500 shift drum interchangeability

[Zack]

Hello,

I am working on a 1985 KX500. The motorcycle will pop out of 2nd gear when under good engine load. I currently have the cases split and have identified a worn groove in the shift drum.
According to some microfiche It appears that the ‘83 and ‘84 shift drum are the same part as the ‘85. I am having some trouble locating a shift drum however- there is one on eBay but I suspect it is mid-titled because the ‘star’ part of the drum looks significantly different. I wonder if possibly all KX500 shift drums might be interchangeable though. the shift drum I removed for my engine is a single piece. I notice most of the newer kx500 shift drums are multi-piece ( the star and bearing are removable from the drum)and this makes me wonder if they would fit/work just fine in my ‘85 KX500. Kawasaki changing the part number because of going to the multi-piece style of shift drum?
Can anyone confirm or disconfirm?

I’m open to any ideas or suggestions

Thanks so kindly
Zack

[kxpegger]

Sandblaster has a parts interchange list but it doesn't look like it covers your years? It's in the "Parts Interchange" thread. He'll probably chime in soon.

http://www.oem-cycle.com/KAWASAKIKX500BIKEID.shtml

[sandblaster]

Some parts list indicate 83-84 and others say 83-85.
The 86-04 drums have narrower slots and will not work with 83-85.
I have actual pics at the shop of both drums so I might be able to tell that way.
But let's be sure of what you have, what is your engine ID?
83 KX500AE000001-001500    
84 KX500AE001501-002400
85 KX500BE000001-001800

[Zack]

Thanks for the replies.
Engine number kx500be001169
Water cooled, non power valve
When you say narrower slots do you mean the slots that the shift forks ride in?
My research shows that all KX500 use the same shift forks which is partially why I thought all shift drums might be interchangeable.

Hopefully, with the forums help, I can get this bike riding again!

Thanks again guys

[KXDINO]

How your gear set check dogs for rounded edges which can make them slip out of gear .

[Zack]

As per usual with a motorcycle jumping out of gear the offending cog (2nd) does have rounded engagement dogs. I intend to repair that damage as well. Interestingly enough, a gear isn’t proving near as problematic to locate as the shift drum.

I am still hoping someone might chime in with more info regarding shift drum interchangeability.

[KXDINO]

If all else fails locating part try kx tech on face book these guys are making shift forks and gears for k5 so a drum they might be able to do. worth a try.

[KXDINO]

sorry it is kx500 tech

[Zack]

I bought and received a used shift drum from a 1987 KX500. Upon initial inspection it looks like it will function as intended in my 1985 KX500 engine. The main difference I see is the ‘87 shift ‘star’ is slightly smaller (has a practically identical pattern but just ‘so’ smaller) It looks that this should not be a deal breaker on it working in the ‘85 engine. The shift drum I purchased did not come with the 6905 bearing so I am waiting on it before I do a better mock up.

I will let you know my findings

[Zack]

I have now received all parts related to the shift drum replacement/upgrade.

My engine is still very much apart but I have the transmission, shift drum, shift forks and shift shaft mocked up in the right side case half. Recall that the ‘87 drum I purchased had a smaller pattern for the “star”, well the ‘87 shift drum/star wouldn’t work with the ‘85 shift pawl- the pawl would catch the ‘nub’ on the shift ‘star’ But would slip off before making a positive shift. Luckily the late KX500 shift pawl is still available new.
Kawasaki part number 13165-1122 PAWL,CHANGE LEVER —$12ish usd

I received the new shift pawl yesterday and compared it to my ‘85. The claw ends of the late shift pawl are closer together. With the new shift pawl installed it now rotates the drum as intended and the transmission shifts gears.

According to microfiche on partzilla the shift drum assembly and shift pawl are the same part numbers from 1987-2004 KX500.

I believe the late KX500 shift drum is a viable replacement for the ‘85 KX500 and likely all pre-1987 KX500. I will give a definitive follow-up one my engine bottom end is back together.

[Zack]

Final update on the KX500 shift drum.

I now have the engine case back together on the 1985 KX500 and the transmission shifts through all gears just fine!

For the swap/upgrade I used the following parts:
1987- 2004 shift drum assembly
Part number 13239-1143
1987-2004 pawl, change lever.
Part number 13165-1122

[sandblaster]

Very interesting.
Let us know how it works after you get it up and running.
Remember... we like vids 

[kxpegger]

Final update on the KX500 shift drum.

I now have the engine case back together on the 1985 KX500 and the transmission shifts through all gears just fine!

For the swap/upgrade I used the following parts:
1987- 2004 shift drum assembly
Part number 13239-1143
1987-2004 pawl, change lever.
Part number 13165-1122

Outstanding and good to know!

[Zack]

One more FYI about switching to the late kx500 shift drum and pawl.

After getting my engine back together and running, I noticed that the shifter wouldn’t return to the “neutral” position. I would change to 2nd gear and in order to get back to 1st gear I had to return the shifter to “neutral” position with my foot before being able to down shift.

I removed the side cover and clutch basket for a better view of the shifting action and the issue was clear. The rear of the shift pawl was actually interfering with the engine case when trying to return to the “neutral” position. This problem was remedied by clearancing the rear of the shift pawl some on a grinder. Maybe 1/16” material removed.
Kinda tough to describe here with words but I am sure anyone who tries this mod will fully understand once the parts are installed.

I have since ridden and the kx500 now shifts fine.

[KXDINO]

Thanks zack , if you want to see something interesting , look up alan millyard and see what he does to kawasaki road bike engines , you be making v twin k5 in no time.