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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => Project Custom Motobricks => Topic started by: Gurujimmy on August 22, 2017, 04:57:55 AM

Title: First Start in Eleven Years Special K
Post by: Gurujimmy on August 22, 2017, 04:57:55 AM
Hi All, this is my first day on the motobrick forum.


So I thought I would share my build, a K75s Cafe racer which i started 4 years ago but had to put on the back burner while I worked away, moved house, extensively renovated and built a new shed.
The last 3 months have finally afforded me the time to complete this project, and today was fire up day.  It has been a process getting to this day with many electrical parts that just said No!, after all it has been 11 years since the bike was last stated. But I have patiently work though all the issues, the last one being the idle switch not engaging which I resolved today, while most of the US was in ecliptic darkness.  No time for frivolous eclipses here in the southern hemisphere.
The good news is the old girl eventually started, how ever the injectors are not supplying fuel when the throttle is in between the idle and full throttle position, I'm sure the answer will be on this forum somewhere.
Title: Re: First Start in Eleven Years Special K
Post by: Martin on August 22, 2017, 05:43:32 AM
Welcome to the asylum from the northern realms.
Regards Martin.
Title: Re: First Start in Eleven Years Special K
Post by: Laitch on August 22, 2017, 05:49:53 AM
Welcome, Gurujimmy! Thanks for the photos.
Title: Re: First Start in Eleven Years Special K
Post by: BRIDGE on August 22, 2017, 06:47:00 AM
thats a very swish paint stripe, is it paint or bare metal?
Title: Re: First Start in Eleven Years Special K
Post by: Gurujimmy on August 23, 2017, 06:16:26 AM
Hi Bridge, it is indeed bare metal. When I discovered that the k tank was aluminium, it seemed only fair to display some of it.


I applied the grain with a coarse 3m pad and then 2k clear over the top.





Title: Re: First Start in Eleven Years Special K
Post by: BRIDGE on August 23, 2017, 08:13:38 AM
Hi Bridge, it is indeed bare metal. When I discovered that the k tank was aluminium, it seemed only fair to display some of it.


I applied the grain with a coarse 3m pad and then 2k clear over the top.


I tip my hat off to then Jimmy, you've done a very good job of it. Have you ever done paint work before?
Title: Re: First Start in Eleven Years Special K
Post by: duckytran on August 23, 2017, 10:34:06 AM
I'd love to see more pics Jimmy. What are you using for tail light? Did you modify the stock muffler or used an aftermarket one?
Title: Re: First Start in Eleven Years Special K
Post by: rbm on August 23, 2017, 10:35:35 AM
Nice build.  Is the gas cap polished or chromed?
Title: Re: First Start in Eleven Years Special K
Post by: Gurujimmy on August 23, 2017, 06:53:33 PM

I tip my hat off to then Jimmy, you've done a very good job of it. Have you ever done paint work before?


I've tinkered with painting a little over the years, but this is my first project of any consequence.
My strategy is an extra coat of clear then sand and polish.
Title: Re: First Start in Eleven Years Special K
Post by: Gurujimmy on August 23, 2017, 06:59:11 PM
Nice build.  Is the gas cap polished or chromed?


Thanks for the compliment.
The cap is not as fancy as chromed or polished, but just simply sanded and grain add with coarse 3m pad (the black one) then clear coated with two pack.


Just check your build what a great retro style... love it.
Title: Re: First Start in Eleven Years Special K
Post by: Gurujimmy on August 23, 2017, 07:11:38 PM
I'd love to see more pics Jimmy. What are you using for tail light? Did you modify the stock muffler or used an aftermarket one?


Hey Ducktran,


I have added a slash cut exhaust, not sure if it's going to be to loud as I wouldn't want to scare the wallabies. The tail light is Cafe style small and round which will mount to the number plate holder which I have just drawn up with auto cad 360 fusion and now need to get cnc routed out of aluminum.
http://bmwspecialk.blogspot.com.au
I will add some more picture or you can check out my blog for full build pics
Title: Re: First Start in Eleven Years Special K
Post by: K75Slark on August 24, 2017, 06:10:59 AM
Welcome!

As weird as this sounds, my K75 had a similar issue that we couldn't figure out for almost 18 months. Turns out taking apart every electrical connection and flushing it with Deoxit did the trick. It seems the Jetronic on these bikes is low voltage and low impedance, even miniscule amounts of oxidation adds up to poor running.

I'm not usually a fan of café'd K's but I really like the look of yours!


Sent from my iPhone using Tapatalk
Title: Re: First Start in Eleven Years Special K
Post by: Gurujimmy on August 24, 2017, 06:43:26 AM
G'day,


Makes sense. The bike was completely disassembled and then sat for a couple of years, I will start working through each connection.
Being duel trade electronics tech/electrician Have tested all inputs in in to the jetronic with the exception of the air flow and temperature.


Thanks for the advice, it gives me another avenue to explore and I'm glad you like the look of the old K.[size=78%] [/size]
Title: Re: First Start in Eleven Years Special K
Post by: duckytran on August 24, 2017, 09:43:29 AM

Hey Ducktran,


I have added a slash cut exhaust, not sure if it's going to be to loud as I wouldn't want to scare the wallabies. The tail light is Cafe style small and round which will mount to the number plate holder which I have just drawn up with auto cad 360 fusion and now need to get cnc routed out of aluminum.
http://bmwspecialk.blogspot.com.au (http://bmwspecialk.blogspot.com.au)
I will add some more picture or you can check out my blog for full build pics


Have you ran it much? I'm interested to know if you're getting a lot of backfire from the exhaust especially from gear 1-3.
Title: Re: First Start in Eleven Years Special K
Post by: Gurujimmy on August 25, 2017, 03:30:42 AM

Have you ran it much? I'm interested to know if you're getting a lot of backfire from the exhaust especially from gear 1-3.




Hey Duckytran,


I only just managed to get the old girl started, so time will tell if I am going to get lots of pops and crackles.
I suspect it will do a bit of backfiring due to lack of back pressure, but I can live with that lack of refinement.
Title: Re: First Start in Eleven Years Special K
Post by: duckytran on August 25, 2017, 08:54:55 AM



Hey Duckytran,


I only just managed to get the old girl started, so time will tell if I am going to get lots of pops and crackles.
I suspect it will do a bit of backfiring due to lack of back pressure, but I can live with that lack of refinement.


Looking forward to your project completion. Love what you did to the tank. I went thru your blog.  :2thumbup:
Title: Re: First Start in Eleven Years Special K
Post by: Rcgreaves on August 26, 2017, 05:38:03 AM
Welcome.  Enjoyed the blog

Sent from my A573VC using Tapatalk

Title: Re: First Start in Eleven Years Special K
Post by: Gurujimmy on August 30, 2017, 04:01:13 AM
OK an update, I have been investigating the no fuel issue. What i have found was the plug/connector that connects the Fi unit to the jetronic had one of the pin pushed back, resulting in a very poor connection, in addition I cleaned every connector.
Now she starts and runs easier and has fuel between the idle and full throttle switches, but was still missing somewhat when I throttled on.
Today I replace the spark plugs and there is a marked improvement, still missing a little and is very fuelly (if that's a word). Next step will be to mixtures right.
Title: Re: First Start in Eleven Years Special K
Post by: Vespa no more on August 30, 2017, 05:28:00 AM
Nice work there
Tank is particularly impressive.


The speedo caught my eye - what brand is it? Am trying to work out a single big speedo (don't think the tacho is needed). Was there many problems connecting to the wires already on the bike?


Also what size headlight did you go for?


Well done. Hope you get to enjoy it this summer

Regards


Guy
(wollongong - just up the road from Tassie)
Title: Re: First Start in Eleven Years Special K
Post by: Gurujimmy on August 30, 2017, 07:09:23 AM
Nice work there
Tank is particularly impressive.


The speedo caught my eye - what brand is it? Am trying to work out a single big speedo (don't think the tacho is needed). Was there many problems connecting to the wires already on the bike?


Also what size headlight did you go for?


Well done. Hope you get to enjoy it this summer

Regards


Guy
(wollongong - just up the road from Tassie)


Are the Gong.......You get much better riding weather than us.


The speedo is from Danmoto it was under the $200 mark around $170 I think. Build quality seems ok for the price. wiring wasn't to difficult, here's a link of what I initially worked out but I'm sure I need to amend it. http://bmwspecialk.blogspot.com.au/2014/12/danmoto-classic-wiring.html
I can't remember the headlight size, I know I based it on the gap between the forks, 7 inches rings a bell. I would go out and measure it, but it's already down to 2 degrees.


If I had the dollars at the time, I would have gone with a motogadget gauge.


Cheers James
Title: Re: First Start in Eleven Years Special K
Post by: duckytran on September 11, 2017, 09:51:39 AM
Hi Bridge, it is indeed bare metal. When I discovered that the k tank was aluminium, it seemed only fair to display some of it.


I applied the grain with a coarse 3m pad and then 2k clear over the top.


Did you use 60 grit coarse 3M pad to get the brush aluminum look?
Title: Re: First Start in Eleven Years Special K
Post by: Gurujimmy on September 12, 2017, 05:57:38 AM
Hi Bridge,


I'm not sure of the grit, but I can tell you it was the coarsest one I could get and it was black in colour.
Title: Re: First Start in Eleven Years Special K
Post by: Gurujimmy on October 20, 2017, 04:44:28 AM
Take 3 on trying to upload photos.


Almost ready for the road.

Title: Re: First Start in Eleven Years Special K
Post by: Gurujimmy on October 20, 2017, 04:49:34 AM
More pictures
Title: Re: First Start in Eleven Years Special K
Post by: Laitch on October 20, 2017, 07:08:29 AM
That's a nice touch including the fork brace in the stripe scheme. To what degree does the grit and moisture spraying upwards from the road under your fender-less fork and wheel assembly become an inconvenience?
Title: Re: First Start in Eleven Years Special K
Post by: duckytran on October 22, 2017, 10:14:31 PM
2nd on the fork brace matching the tank. Very nice indeed.  :2thumbup:
Title: Re: First Start in Eleven Years Special K
Post by: Andrew2 on October 23, 2017, 09:07:35 PM
  Nice work Jimmy. I never used to like K-series cafe' racers but they're really starting to grow on me.

 Cheers
 Andrew