Hi there. My name is Kris but most call me Red. I've recently purchased an 85 K100RS that is in need of a little TLC. So far, I've replaced the speedo sensor (pick was broken off by PO) & cleaned tightened the speedo connections.

Now I have to address the seals in the oil/water pump & I'm a bit confused. First, let me start by saying that I'm pretty sure they need to be replaced due to the oil leak that appears to be coming from a weephole in the front of the engine on the curbside of the bike. I've read a few threads on this site & others explaining the procedures & differences in the parts. I don't want to disassemble the bike & have it down so I'm going to assume it's got the original shaft with the nut attached impeller & that it's of the 19T variety on the other side. According to the diagram here: http://www.ascycles.com/Illustrated_catalog2/MicroList.aspx?id=51752&catID=11&catName=11+Engine&bindName=11_1818+WATERPUMP%2fOILPUMP+-+OIL+FILTER&bindCat=11_1818 I'll be needing numbers: 13, 14, 7, 8, 11, 15, 10 & maybe 27. Does this look right?

Actually, now that I'm thinking about it, it looks like I'm going to have to pull things apart to verify whether I have the 19T or 32T shaft otherwise I could end up needing a drive shaft as well... Or is the 19T shaft even available anymore?

Any advice would be appreciated


Thanks,


Red

Got to www.motobins.co.uk and have a look at the kit they sell to 'upgrade your water/oil pump. Many of the original parts are NLA (and also not interchangeable with the new items) and so you will likely have to retrofit the newer components to your bike. The easiest way to tell what you have is to whack the front cover off the pump and see if the impeller is cast or stamped. The later design is stamped and held in with a bolt rather than a nut. Order a new impeller and the mechanical seal kit and you'll be laughing, as we say Down Under.

I lived in Easthampton, Northampton and Williamsburg from '83 through about '92. Not far from Westfield they are, my old stomping grounds. I have a daughter in Noho. Welcome to the forum.

Thanks for the advice, I guess I'll just drain the coolant, pull the cover & should have a better idea then.

Two Wheels Better wrote:I lived in Easthampton, Northampton and Williamsburg from '83 through about '92. Not far from Westfield they are, my old stomping grounds. I have a daughter in Noho. Welcome to the forum.

Nice. I've been around here for most of my life save for a couple of years in Colorado. I rode through all those towns today! Nasty road conditions northwest of Williamsburg, though. I was clenching pretty tight a few times!

Just to get you going:
a. old vs new pump impeller



b. the bits you will need


c. the reason you may need a new shaft

Well, I've got a cast impeller with a nut on it so it looks like I'm going to have to go with a new shaft, bushing, impeller & bolt to go along with the seals. I'll be calling around for parts tomorrow.

Thanks for the help!

You are not so far from AJ's Cycle BMW up on the Mohawk Trail in Gill (the other side of Turners Falls). It's been many years since I visited the proprietor, Allan, but last time I was travelling through the area (early 2007) he was thriving. Motobins can ship in under a week to Australia so it must be far quicker to the East Coast of the States. They're a lot less expensive than the dealers as well. Pity you can't also get the option of Motorworks UK but for some reason they won't post to North America.

Good luck and when the bike's smoothly running get out for a long ride. You'll see the reason for and the beauty of the bike over the road. They reward gentle inputs and smooth throttle application. It's not by nature a sportsbike, but I for one reckon she'll bring you some smiles with the miles. Well handled they'll surprise the squids in some cornering situations.

You mentioned elsewhere that you're sorting the suspension. Try Realm Engineeering for the rear shockie (Ram), from the UK. Progressive make a spring for the forks and you can fiddle round with viscocity of the oil. I like 5W and a firmer spring. Telefix make a fork brace for 84/85 models and RT/LT that didn't come with them. This is a big improvement. Optionally, there's always the latter, two-piece mudguard and fork brace built in to the fork legs.

Thanks for the tip on Motobins -way more affordable than from a dealer!

I was planning on some PRogressive springs & maybe a shock a bit later in the riding season. Believe it or not, with the preload backed all the way off, the rear isn't too, too bad but the front is pretty harsh. I'm afraid of rough road in the middle of a turn sending me into the weeds or worse, oncoming traffic!

I was going to take a ride up to Gill to check out AJ's with my son this weekend. I'm going to see if they'll give the bike an inspection & make some recommendations for necessary maintenance to be addressed. I can do the work but I don't really know what I'm looking at aside from the obvious...

Ugh. Motobins doesn't have the shaft. I guess I'm going to have to call around stateside & see what I can come up with.

Is it possible to convert to the 32T shaft if I use the corresponding drive gear? Or will that not fit into the line to the filter?

No, it will not fit into the pump body. The diameter of the later gear wheels is different. The large one is larger and the small one is smaller. The pump bodies for the two types are different but interchangeable. Check out the picture of the old and new type pumps that I posted in this post on the forum.

http://k100rt.aforumfree.com/t126p15-oil-leak-from-oil-pressure-sensor-wire-hole?highlight=oil+water+pump

My k100 rt (10 1985) has the original design with the tip of the shaft extrnally and the impeller (cast steel) is held with a nut.
That time  seal was provided  by SIMRAX  and there was no spacer.
Design was changed and seal is provided by KACO which is quite longer.
I purchased a KACO seal from motobins  however when i tried to fit the impeller, this is pushing the seal more than it should be and the shaft stop turns.Fortunately seal kit was together withthe spacer. What i am gonna do is to machine the impeller to reach the same "depth" with the spacer.

Hi Red,

I did a job just like that not long ago.
You can check out the thread here :
https://www.k100-forum.com/t16771-first-major-service-on-my-own#194023

I also strongly advise to check out the following material in order to be on top of the assembly procedure: 
http://www.kforum-tech.com/mechanical/oil-pump/oil-pump-seals-replacement.htm
https://ibmwr.org/index.php/2003/05/01/water-oil-pump-rebuild/


Pay particular attention to the direction of the oil and water seal when you put those into the pump housing. Also use a threaded guide with a washer to get the shaft through the seals.


Hope the info is useful.
Cheers,
Einar/