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Messages - fisjon
1
« on: May 28, 2015, 04:48:56 PM »
Back in the 70's some guy just stuck two CB750 motors in a frame one behind the other and went drag racing!
cool, as they used to say............
2
« on: March 30, 2015, 04:45:14 PM »
Hi 'Billy'
This is john here from Caerphilly, is this the beast that I did the carbs for? If so then I can say that the carbs were definitely on the bike tidy, the carb balance correct and the ignition timing and points dwell spot on.
I do remember that the engine had a habit of racing up on it's own for no apparent reason and a it came back down when it felt like or after you blipped the throttle a few times, that might have been the fuel supply as it was a temporary arrangement at the time.
The only other thing I can think of that would cause that is a sticking advance retard mechanism. You say that you have checked this out, but did you remove it and clean up, lube and re-fit or did you just check with a strobe. If you checked with a strobe it still might be temporarily jamming up and that would cause misfire/popping but this would be on all fours pots. The other thing is the springs, are they the correct ones as I seem to remember they are different strengths.
The problem with these old Honda electrics is that they have a very weak spark to start with, if there is an electrical fault it won't take much to upset the spark output.
Just a thought.
john
3
« on: February 02, 2015, 06:45:56 PM »
Julie I would offer to do them for you but for the fact that my US cleaner (600watts) blew up and took out my electrics in the garage. It cost me £400 to have a new consumer box and the garage rewired! The best cleaning fluid to use in a US cleaner is' US-CAR' available from R&D Laboratories Ltd ( www.mistralie.co.uk) I can guarantee from experience good results using this product. Here's another one I did earlier  john
4
« on: February 02, 2015, 06:07:51 PM »
Hi Julie,
I take it you paid for this to be done, if so you should take them back and get them done again. If they moan about it just tell them that you will let everyone know that they do inferior work.
If any of the 'grit' is left inside the air/fuel tubes then you are going to have probs. I had an ultrasonic cleaner and I had nothing like that in any of the work I did. for an example see photo.
Everything I put in came out clean as a whistle with no crud or powder. I suspect they are not using the correct cleaning agent.
john
5
« on: January 17, 2015, 03:19:39 PM »
The Boyer system I fitted to the CB650 was a complete system, coils an all. Not one item of the Honda set up was retained. It cost £170 and was worth every penny. I could not believe the difference.
The engine started up instantly as you pushed the button, no delay.
The exhaust sounded crisper.
Throttle response was positive with no flat spots or hesitation.
Considering the CB650 came with electronic ignition as standard the difference between the two was a revelation.
It was like having an extra 100cc added to the bike.
I've used strobes and dwell meters to set up points/ignition but it doesn't matter how good you are you will not get the same performance improvements that will come with a full electronic system. If you take you time and put it in carefully you can then forget it, no maintenance required.
Don't be a dinosaur, go get a Boyer.
6
« on: January 13, 2015, 07:17:11 PM »
Boyer gives smoother tick-over, better acceleration, better mpg, better performance. END OF!
All due to a huge big fat bright blue spark always fired a the right time. The Honda points system is like a wet fart (a tiny little yellow putt) compared to the Boyer. If you haven't seen a Boyer spark to compare, you can't make a comparison. No contest. Those of you stating that the points system is better are just harking back to the 70's for the hell of it. Wise up guys. Oh, and maintenance free!
7
« on: January 06, 2015, 11:53:41 AM »
The Honda electronic ignition system on my CB650 was futile so I ripped the whole thing out and replaced it with Boyer. If you see the power of the spark that the Boyer system supplies (it's like an arc welder), you won't want to use anything else.
8
« on: July 01, 2014, 03:42:01 PM »
9
« on: April 06, 2014, 09:32:48 PM »
I had a brand new CB750K1 back in 1971. (cost £719)
When it rained, the bike just cut out. When I took off the metal plug cap covers it improved but occasionally misfired. So I covered the caps with heat resistant insulating tape and that cured the problem. The thing is that the metal covers on the original equipment were there to stop radio interference! Nowadays of course the caps come with resistors.
The original points, coils and caps were total rubbish and produced a puny spark. If you have these on your bike then you should consider putting electronic ignition on. You simply will not believe the difference. It will run smoother, have more power and do more miles per gallon. The difference between the spark on original fit and Boyer electronic ignition is the difference between striking flints together and a bolt of lightning. I speak from experience, you don't want to be holding a spark plug against the engine to 'test for spark' when it is attached to a Boyer kit.
Having a fat spark will eliminate a lot of problems associated with carbs. Good combustion will take full advantage of any carburettor.
What you describe however could be something simple........advance and retard..............remove the points plate, take the advance retard off, dismantle it and give a thorough clean. Reassemble with plenty of engine oil, (not grease as this dries up and causes it to jam). Note, it should have two springs attached that are different. One is stronger/heavier gauge that the other. What happens if the advance retard is not working properly is that it temporarily jams and of course changes the ignition timing for any given amount of revs, this will cause loss of power pulling away but will be ok at higher speeds. If you balance the carbs when they are jammed open, when they release the carbs will need rebalancing again.
It could also be the transition between the jets that is causing the problem. I would get the carb bodies ultrasonically cleaned to make sure that there are no blockages or small particles of crud bobbing up and down in the drilled airways. If you can't find anybody local to do them I can do them for you.
Hope this helps
10
« on: March 28, 2014, 08:53:15 PM »
Hi Bitsa,
I bought the cb650z as a complete wreck and it cost £4,300.00 to restore, it was a love hate relationship as it was really nice to look at but wasn't very nice to ride, not a lot of power and brake weren't very good, but then that was the seventies/eighties. I also had a VF750FD at the same time so, reluctantly the CB had to go. Sold for £2.700 and then I sold all the spares I had for £900 so just about broke even. It took 18 months to do.
Hi Green1,
It looks like RS paint sent me the wrong base paint then, they sent me Silver Base not Metallic Silver Base, no wonder I could not get it quite right.
cheers
john
11
« on: March 27, 2014, 07:28:00 PM »
Hi 'Billy'
John here from Caerphilly, my CB650Z was Candy Antares Red. If it's 'Candy' Antares Red it is definitely metallic.
You can get it from RS paint, it is a three part kit:
1. WB Honda 726 Silver Base
2. COB Honda 726 Candy Antares Red (it's a lacquer)
3. Clear Gloss Lacquer
I bought a new tank and side panels for the bike but could not get a new tail piece so I had to paint the old one. Not easy I can tell you. Probably the hardest thing I have ever tried to paint. One squirt too many and you have ruined it. Got a reasonable finish on the 3rd attempt, but each time you cock up you have to strip right down again as the silver base needs to show through the lacquer to get the right colour.
I've got a can of each! might be enough to do a tank...........just might
john
ps there might be a difference of opinion as to whether Candy paint is metallic, it is different from 'Flake' metallic but I would say that it is metallic. It is the same finish as the gold CB750K0/1/2. I think the correct term is Candy Apple finish.
12
« on: March 19, 2014, 05:44:57 PM »
Hmmmmmnnnn..............could loose a few nuts and bolts down there............................ 
13
« on: March 15, 2014, 02:14:54 PM »
I thought these were unobtainable, obviously not. Must have got my wires crossed somewhere!!!!!!!!!!!
14
« on: March 14, 2014, 07:47:23 PM »
15
« on: March 11, 2014, 11:18:16 PM »
Hi,
I put a Boyer Micro system on my CB650Z. I found that if you set it up as per instructions, ie, set the timing to full advance at 4000 revs it was a bit revy. So I simply timed as per contact points, ie, at the F mark on the flywheel and I had no further problems. The bike ran well and was quite torquey compared to the original electronic system.
If you set the timing at the F mark and you are still getting revs make sure that the push pull throttle is correctly adjusted as this can cause revving to occur. Make sure there is enough slack on the 'push' cable.
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