"Revive" (1985 K100 Street Scrambler Build, not a Cafe Racer)

[rbm]

This US / UK measures are confusing.  I much prefer Metric.  Anyway, the actual numbers should be as follows:

UK:
tank size = 3.3 Imp gal., distance = 115 miles, fuel economy = 34.8 mpg Imp.
34.8 mpg Imp.  = 8.1 l/100Km (that's what my car gets!)

US:
tank size = 3.9 US gal., distance = 115 miles, fuel economy = 29.5 mpg US

Two up on a K-bike with luggage in a hilly country probably should get 5.5 - 5.8 l/100km. Let's take the worst.

5.8 l/100km  =  48.7 MPG Imp.  =  40.5 MPG US.

[DJEwen]

You're running 115 miles on 3.3 Imperial gallons, which gives you 34.8 miles/imperial gallon.  In metric, that's 6.75 l/100km.  That's not too good.  You should be more in the region of 5.3 - 5.5 l/100km which is 53.2 miles/imperial gallon.

Here's a link to my Fuelly results for my K75.  A K100 should be close.


With the lumpy response and the rather poor showing on fuel economy, there might be something up with the water temperature sensor.  It might also be the "Z" tube leaking between the crankcase and air plenum.  Try the test using propane gas around the TBs while the bike is running.  Lots of threads about how to conduct that test.

I highly doubt that TB sync problems gives you the symptoms you're seeing but it certainly will help towards fuel economy and better running to do that procedure.

Thanks for the useful information, Robert. Which temperature sensor do you suspect? The one in the stand pipe? I’d hope it’s not the crank case breather hose as it’s new.  I’ll search the threads on the propane leak finding.

[oneplustwo]

Sorry to back track your thread a bit.  I got almost the same saddle as you.  Can you help me understand how you chopped the frame to fit?  It looks like you took a section out ahead of the taper in the tubing toward the rear.  Did you just choose the middle section between the taper and the intersection near the tank?  Any other tips or advice you would recommend?

[DJEwen]

Sorry to back track your thread a bit.  I got almost the same saddle as you.  Can you help me understand how you chopped the frame to fit?  It looks like you took a section out ahead of the taper in the tubing toward the rear.  Did you just choose the middle section between the taper and the intersection near the tank?  Any other tips or advice you would recommend?

Hello there. Back track away, no worries. That’s correct, the saddle was 140mm shorter than the frame, I simply taped the thickness of the masking tape at the taper then cut 140mm out up stream of that. That 140mm lost 15mm overall over rear hoop width so I mounted the hoop in the vice, heated the bends and gently forced outwards to make up the gap, I then dressed the cuts and had it welded. Hope this helps.

[DJEwen]

Upon removing the damaged rear light it became apparent that the 2-up run had contributed to some heavy damage too. I guess the rider isn't so svelte  :giggles You could argue this makes my design flaw worse but the deflection plate and a reduction in rebound on the Hagon Shock should counteract future damage.





I cut out a plate from some 1mm sheet steel, bent in a rear section and drilled some holes. The rear light finishes at a 45 degree angle, I made sure there was enough plate to run parallel with the finished line of the reflector. I painted it with 4 coats of black gloss in a rattle can.







Finished article mated with the replacement rear light and then through bolted to the frame.











It doesn’t look too cave man like. Time will tell if it functioned as intended.

I also stole, cleaned up and mounted the rear tank pad from the spare bike.

[DJEwen]

And I like this shot...

[DJEwen]

I’m 848 Miles in now.



After returning home from a 70 mile trip, as I was cruising up to the garage the bike died and wouldn’t restart.

I took this video but it wasn’t until I listened to it back that I realised I couldn’t hear the fuel pump:



Here’s the culprit:



I don’t have any 7.5 amp fuses, my fuses range, 5amp, 10, 15 etc. I replaced it with a 5 and the bike started after a couple of cranks.
Will a 5amp be ok, would a 10amp even? Does anyone have any ideas why it will have blown the fuse? It’s hard to tell the age but lt looks as old as the rest of the bike before the rebuild.

Again, the 3x 7.5amp fuses were the only ones I didn’t change as I didn’t have that size.

[alabrew]

When I was blowing pump fuses, I went up to a 10 amp until I made the 4 pin connection better. Recently remembered to reinstall the 7.5 amp..

[rbm]

Did you add any additional loads on that circuit in the course of modifying your bike?

[DJEwen]

Did you add any additional loads on that circuit in the course of modifying your bike?

Nothing added, no.

The bike died on me 3/4 of a mile from my house this morning. The 5 amp had blown so I changed it for a 10 but I'm getting nothing now, no fuel pump and no blowing fuse. It appears both times it blew were upon closing the throttle.
Pushing a K100 in full kit 3/4 of a mile at 0630 in the morning isn't much fun.

So what do I do next? Pull the pump and test it direct to the battery first then start working back down the line?

[Laitch]

So what do I do next? Pull the pump and test it direct to the battery first then start working back down the line?

Yes. Be as certain as you can though, that the fuel injection control plug pins and wiring aren't playing up again.

[Skunky]

Yes. Be as certain as you can though, that the fuel injection control plug pins and wiring aren't playing up again.

+1 on that Dave, Take a methodical approach, Before you toss the pump check its getting voltage. If its not work back to the 4 way plug, if it is new pump. I would wager it isn't. Although the fact that your blowing fuses shows something is shorting. You had the frame powdercoated so you may be having a clean earth issue. IF your'e not getting a good earth it can do all sorts of weird shit where your power is all over the place. You could always put in a new 4 way connector to elinate that.
Laitch and Rbm put me onto Bertram Vogels troubleshooting guide and its invaluable when you have issues like yours.

 http://k-bike-knowledge.000webhostapp.com/electrical/EFI/bike-wont-start-EN.htm

[DJEwen]

Yes. Be as certain as you can though, that the fuel injection control plug pins and wiring aren't playing up again.

What more can I do with the FIC plug that I haven’t done already?

+1 on that Dave, Take a methodical approach, Before you toss the pump check its getting voltage. If its not work back to the 4 way plug, if it is new pump. I would wager it isn't. Although the fact that your blowing fuses shows something is shorting. You had the frame powdercoated so you may be having a clean earth issue. IF your'e not getting a good earth it can do all sorts of weird shit where your power is all over the place. You could always put in a new 4 way connector to elinate that.
Laitch and Rbm put me onto Bertram Vogels troubleshooting guide and its invaluable when you have issues like yours.

 http://k-bike-knowledge.000webhostapp.com/electrical/EFI/bike-wont-start-EN.htm

Copy that. I’m not going to do anything rash.

I’d hope it’s not an earth fault, I stripped a 1mm brown core from some household 2.5, sleeved it and ran it from the mount under the tank to the battery then onto the Gearbox making sure the ring terminals were touching bare steel and aluminium.

I have 2 copies of Bertram’s in the garage, I’ll read through it once my dummy is back in my mouth.

[Laitch]

I pulled the plug from the Ignition Control Unit in the head and attached the old ICU and went for start whilst twisting the connection into different positions during start- this identified the plug as the problem . . . Twisting position dictated fire/no fire.
I heavily dosed both male and female connection to the ICUs with electrical cleaner and vigorously cleaned with a paint brush, left them to dry then repeated the process.
Once dry for a second time I plugged back in as standard position and started. The bike ran with no issues- she heated to 80c and the fan kicked in and out as needed repeatedly.

Will twisting this connection cause the fuse to blow, or the bike to stall when running again as it did previously? If it does, there might be a short within that harness or faulty connectors. Otherwise, checking from the pump to the four-pin connector and onward is the way to go. While you're resting, clean the fuse slots with fine emery cloth and get some 7.5A fuses and replace all the ones currently being used.

[Laitch]

What size is the front Scout? Is it a Front/Rear type or is it a Rear? Is it a TT or a TL? If is a TT, did you mount a tube in it?

[DJEwen]

What size is the front Scout? Is it a Front/Rear type or is it a Rear? Is it a TT or a TL? If is a TT, did you mount a tube in it?

Rear type tyre, front mounted, 120/90-18, tubed.

[Laitch]

Rear type tyre, front mounted, 120/90-18, tubed.

Did you reverse its rotation direction?

[DJEwen]

Did you reverse its rotation direction?

Only when I’m pushing it backwards...

[Skunky]

Only when I’m pushing it backwards...

Pushing it a bit too much Dave  :hehehe. Seriously though have you got it sorted now?.

[DJEwen]

Pushing it a bit too much Dave  :hehehe. Seriously though have you got it sorted now?.

Haha, 3/4 of a mile was enough, Gary, never again! Nope, not sorted it, I’ve attempted it a few times, gone into the garage, looked at it for 3 minutes but ended up turning round and pouring a whisky instead.

I’ll get round to it...

[Skunky]

This could be the answer or at least eliminate the connector

https://www.ebay.co.uk/itm/Tyco-AMP-Electrical-Waterproof-Connector-Kit-1-2-3-4-5-6-Pin-Way-Superseal-Car/231993136001?_trkparms=aid%3D555017%26algo%3DPL.CASSINI%26ao%3D1%26asc%3D53380%26meid%3D4724fffa322f4a5a94756e57858ed5f2%26pid%3D100505%26rk%3D1%26rkt%3D1%26%26itm%3D231993136001&_trksid=p2045573.c100505.m3226

[Enfield]

Damn still looking Good!
 Couldnt help noticing your chicken strips on the picture! Exact same spot as mine - do you find that the 140 tyre is so “round” that it would be “ unhealhty” to go further Down doing corners?  I sure feel something Like that 😅
Guess it would be different with a wider rim!
What about the 120 in front is that ok? I run 4.00 - 18 - works Great - but still very round!
Regards
Chr

[Enfield]

Forgot the quote from the post i refer to - but I suppose you know what I mean 😇

[DJEwen]

Hello again,

Excuse my absence, had a lot going on at home. Thanks again for the assistance and to those of you who reached out privately in aid of repairing my mechanical horse.

It’s been two months since I pushed the brick home and since my dummy is back in my mouth I decided to head out to the garage and see what the story was. I was confident that the fuel pump had shit the bed so skipped a handful of steps on Bertram’s fuel injection trouble shooting process flow and went straight in to pulling the potentially offending item out. I stripped a couple sections of wire and bench tested the unit directly to the battery and got nothing but a click, I attempted reversing polarity to free the unit but this was equally as successful, findings below, would you agree the pump is finished? I’ve already found a replacement on fleebay for £25 on a 48hr courier.

There’s a Gentleman’s ride out this Sunday to raise money for a cancer charity, would be cool to get the Brick rolling without pushing it.







PS: Click the Brick...

[Skunky]

Welcome back DJ. Looks like the fuel pump is fooked. Can't do any harm to change it for £25 anyway, but your cutting it fine for the rideout. #FUCKCANCER  :2thumbup: