K75 warm up problem

[Wirelic]

Hi All

I recently acquired an 88 K75 with 66000 miles on it. It has a problem warming up. When starting out cold, it will stall out at stop signs, etc. after it gets good and warm, it runs ok. Any ideas or help will be greatly appreciated.

[Laitch]

I recently acquired an 88 K75 with 66000 miles on it. It has a problem warming up. When starting out cold, it will stall out at stop signs, etc. after it gets good and warm, it runs ok. Any ideas or help will be greatly appreciated.

Welcome!

When a used K is purchased, the first priority should be reviewing the condition of its fuel tank interior, its spark plugs, its in-tank hoses and hose connections, and the valve clearances—at the bare minimum. Replace the fuel filter. Use fresh fuel in it. There is a BMW K75/K100 2V workshop manual in the Service Manual section. Download it. Get a Clymer manual and a Haynes, too, to help get different perspectives on procedures.

Describe what you know of the history of this moto and let us know what you have done so far regarding assessment of it. Post a couple of photos of it.

[Motorhobo]

Hi All

I recently acquired an 88 K75 with 66000 miles on it. It has a problem warming up. When starting out cold, it will stall out at stop signs, etc. after it gets good and warm, it runs ok. Any ideas or help will be greatly appreciated.

What's wrong with that? Engines need to warm up, that's why they put chokes on them. Have you just tried cranking the 'choke' lever (which is not actually a real choke, all it does is increase the throttle a couple notches) until the moto warms up? If it runs well when it's warm then doesn't sound like there's a problem. Unless it's not running on all cylinders until warm, in which case you have a problem.

What Laitch said is also valid, but I don't know anyone who acquires a bike and immediately starts tearing into it, pulling off valve covers and the like. When I get a bike that runs, I want to run it for a while to see what issues pop up, assuming it's safe to ride.

But be prepared to do all the things Laitch mentioned sooner rather than later, especially plugs, fuel filter, spline lube and valve clearance check. Assuming you want to keep this bike on the road for a while, that is.

[K1300S]

What Laitch said is also valid, but I don't know anyone who acquires a bike and immediately starts tearing into it, pulling off valve covers and the like. When I get a bike that runs, I want to run it for a while to see what issues pop up, assuming it's safe to ride.

LOL...I do.

these things are old. unless the bike comes with extensive maint documentation....it gets taken apart to check and replace all the old crap that if it isn't broken already, soon will!

[stokester]

Hi All

I recently acquired an 88 K75 with 66000 miles on it. It has a problem warming up. When starting out cold, it will stall out at stop signs, etc. after it gets good and warm, it runs ok. Any ideas or help will be greatly appreciated.

Check your valve clearances.

[jaxon]

I was going to suggest a bottle of champagne, a nice fire going and some Barry White playing in the background.

But then I realized Laitch is on target.

[alabrew]

Welcome Wirelic. Sounds like my ’85 before I found the split intake boot. Check the “z” tube too as they are known to crack.

[rdivy725]

I had the same issue with my 94 K75 that I bought last fall. If I didnt leave the "choke" (throttle advance) on for 15 minutes, it would stall out, especially on throttle tip-in from a stop. The ambient temp was around 50-60 degrees. I replaced the split z hose, ran fuel cleaner, changed plugs, oil, etc. The last time I took it out, the battery was weak and I had to jump it. It still had the cold running issue.  I replaced the battery this past weekend and took it out for the first time. Ran like a top. Its never idled so good, and I only used the "choke" lever for a short time. I am leaning on my issue being a weak battery.

Many things that everyone listed above can contribute to your concern. Even though the battery may seem ok, its state may not be enough juice for the FI system to operate properly. Start with the basics.

[Wirelic]

Guys,

I give a huge thank you to each one of you who replied. I do appreciate your help and expertise. Just so you know, I’ve been riding & wrenching on bikes since 1967, when I bought my first motorcycle. It’s been mostly British bikes, though, this is my first BMW.  So I thought I’d go right to the experts on this bike to help with the issues related to it.
I’ll definitely post photos and keep you updated as to the progress and what I find. Thanks again to all.

[Wirelic]

Laitch,

Please direct me to the shop manual you mentioned as being available to download. I’ve done a number of searches on this site but can’t find it. Thank you.

[Laitch]

Go to the top of this page. Click Home. Look for the Technical Directory section on that page. Click on Service Manuals. Click on K75 K100 2V. Download the PDF. After that, go back to Home. Click on Motobrick Workshop then click on How to Effectively Search MOTOBRICK.COM.

[Wirelic]

Laitch,

Thank you. With your directions, I did find the manual.

[johnny]

greetings...

its the 4 pin...

j o