Author Topic: 71 k1 issues  (Read 2662 times)

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Offline mycb750k6

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Re: 71 k1 issues
« Reply #25 on: July 20, 2010, 06:14:01 AM »
OP...maybe it's time for some photos or videos. This doesn't seem to going anywhere.

Offline khardrunner14

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Re: 71 k1 issues
« Reply #26 on: July 20, 2010, 07:19:36 AM »
Sorry to give you that impression. I'm really getting a lot of ideas. I will be working on the bike again thursday so I will try to get some photos/vid up. As of right now it seems I need to:

1) re-set the valve clearances...making sure I'm at tdc
2) work through static timing to see if I can get it close that way
3) check the carbs again
4) check for good spark on each cylinder

That's the plan for thursday. Maybe I can get it to run again and that way you guys can hear it. If you have any additional things I should do please let me know.

Offline Spanner 1

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Re: 71 k1 issues
« Reply #27 on: July 20, 2010, 11:31:53 AM »
Basically if the points cam advancer is sticky, when you go to set your timing at the F mark ( i.e. points to open at the F mark ) the cam may be already turned part way and your points are now opening too early = timing advanced at idle.
Worth checking/cleaning/lubing anyway if you have never done it. Simply remove the 3 screws from the points plate ( mark the position of the plate with a Sharpie first so it can go back in exactly the same spot ) remove the points plate . Undo the 10mm nut at the end of the cam and slide it off. Take care of the locating dowel pin on the back of the mechanism. Hold the advance plate and turn the cam to see operation of the springs etc... Is it good and free?.... lube where necessary lightly and re-install. Some advance units are sticky when the bike is cold and free-up with engine heat IMO.
My bad....... the T and F mark are 'fixed' to the crankshaft of course, so T would always be Top Dead Center, but the F mark would be false if advancer not releasing........
« Last Edit: July 20, 2010, 11:36:48 AM by Spanner 1 »
If your sure it's a carb problem; it's ignition,
If your sure it's an ignition problem; it's carbs....

Offline khardrunner14

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Re: 71 k1 issues
« Reply #28 on: July 20, 2010, 11:34:31 AM »
Thanks, I'll try that!

Offline techy5025

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Re: 71 k1 issues
« Reply #29 on: July 20, 2010, 07:53:48 PM »
Is there any possibility that while adjusting the valves or something else you either reversed or swapped the connections to the coils under the front of the tank? I don't know if you disconnected and reinstalled them or not. You can also reverse then at the connection behind the engine.....or at the points. Just throwing out long shots.

The engine will run..very badly...on two cylinders so it sounds like you aren't hitting on any.  ???

Jim
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1969 750 K0 (Reborn)
1969 Sandcast 750 K0 (Reborn)
2003 CBR600F4I
........

Offline khardrunner14

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Re: 71 k1 issues
« Reply #30 on: July 21, 2010, 03:48:19 AM »
I was messing with the coils early on the day I did the valves. I'm fairly certain I got things back correctly, but I will double check those connections.

Offline khardrunner14

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Re: 71 k1 issues
« Reply #31 on: July 23, 2010, 09:42:46 AM »
UPDATE: It's running...on 1 and 4 only though
 I put in another 4-5 hrs yesterday and today and here's what I did:

1) adjusted valves cold...again
2) checked fuel bowl levels and increased levels on 1 and 2 since they were only about half full
3) static timing done to perfection
4) clipped and reseated plug boots for 2 and 3 to be sure I had a good connection
5) checked and compared spark on all cylinders (screw driver method)
6) adjusted cam chain as per clymers
7) checked strobing timeing using a light... 1 and 4 perfect, NO STROBE on 2 and 3 so I couldn't tell
8) set points level both with feeler and tried using dwell tach... more later on that

Obviously its no good still on cylinders 2 and 3. I'm currently uploarding a vid to show it running but it's taking a while. The video was taken right after I tried using the dwell tach to set the point gap.

When I tried to use the dwell to set point gap it required me to close the points significantly to reach the correct dwell of around 48-49 degrees (set on 4 cyl mode). It ran worse, though only slightly when I closed the points to achieve the correct dwell... somthing isn't right there. I re-set the static timing and the points using the ohm meter and feeler guage.

There is some back fire, especially at higher rpm. It is tough to get it to idle, though since I reset the points it's better.

All of this of course does nothing to explain why 2 and 3 won't fire. I compared spark from 3 and 4 using the screwdriver method and achieved similar results so I have spark. It can't be anything to do with fuel delivery to the carbs since 1-2 and 3-4 are together on that. I checked fuel bowl levels and they are pretty high maybe l--l to l---l from the top of the fuel bowl.

movie later as soon as it comes up. Why can't I get 2 and 3 to fire???

Offline khardrunner14

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Re: 71 k1 issues
« Reply #32 on: July 23, 2010, 10:33:30 AM »
Try this... having troubles with photobucket so maybe maybe not on this

http://s214.photobucket.com/albums/cc197/khardrunner14/?action=view&current=bikeafterdwelltry.mp4
« Last Edit: July 23, 2010, 02:06:36 PM by khardrunner14 »

Offline khardrunner14

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Re: 71 k1 issues
« Reply #33 on: July 23, 2010, 01:40:07 PM »
Alright I got 4 cyls now!

Swapped a used condenser and point set in for 2-3 and found I had good spark with a driver. Still only had cylinder one though. I pulled the plug from 4 that had been working before and tried for spark with that...no dice. Same with 2 and 3. Put new plugs in and finally a rideable bike.

Still a bit sluggish for sure. I think I can feel lean surging but I can't tell for sure. It almost feels "fat", especially at WOT.

At least it's somewhat rideable now....more work to do yet I guess.