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No top end speed
- kwak750ltd
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Attachment IMAG0281small.JPG not found
All the work done so far is by me. Respray, rear light, front indicators off my old 440 ltd. rear frame sprayed up after sand down, Battery box bent back into shape and resprayed red. electrics sorted after blowing 2 out of the 3 fuses when i first took it out. And fitted a replacement front fork name badge. Still loads to do but It's a custom. I can have it how I like.
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- 650ed
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I'm not sure what you mean by thrashing the engine. Are you saying the engine runs poorly above 4200 rpm, or is it that you are concerned that the rpm are too high at 55 mph? If it's running poorly you need to clean the carbs and perform a full tuneup. These engines are engineered to run perfectly fine at high rpm and are perfectly happy to run hour after hour at rpm higher than 4200. Notice in the chart below that they make less than half their peak hp at 4200 rpm. Ed
Attachment 00003a-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20-21-22-23-24-25-26-27-28-29-30-31-32-33-34-35-36-37-38-39-40-41-42-43-44-45-46-47-48-49-50-51-52-53-54-55-56-57-58-59-60-61-62-63-64-65-66-67.jpg not found
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- kwak750ltd
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- GPzMOD750
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My exhaust was beat up and leaky so I put on a 4-1 system and it actually made it worse. I ended up having to rejet, fiddle with the timing, sync and resync the carbs cut off the stem on my intake cap.......
It's going to take some fiddling.
Another issue is that gas isn't the same as it was when these bikes were built so sometimes the recommended factory carb and timing settings are no longer the best setup. You can try non ethanol gas if you have somewhere local that sells it.
Edit: Just realized that you are over the pond so I don't know if you even have the stupid ethanol gas.
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- martin_csr
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630 sprockets.
33/13 = 2.538
32/13 = 2.462
34/14 = 2.429
33/14 = 2.357
30/13 = 2.308 <<>> this is probably about as low as you'd want to go, but it might be a tad too low.
32/14 = 2.286
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- kwak750ltd
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- KZB2 650
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1978 KZ650 b-2
700cc Wiseco kit 10 to 1.
1980 KZ750 cam, ape springs, stock clutch/ Barnett springs.
Vance and Hines Header w/ comp baffle and Ape pods, Dyna S and green coils, copper wires.
29MM smooth bores W/ 17.5 pilots, 0-6s and 117.5 main
16/42 gearing X ring chain and alum rear JT sprocket.
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- kwak750ltd
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- missionkz
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However, I wonder if the OP is actually experiencing clutch slippage?
Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado
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- GPzMOD750
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missionkz wrote: A bit hard to understand the complaint here as the terminology is a bit vague, and gearing vs RPM vs sprockets and symptoms doesn't make a lot of sense to me.
However, I wonder if the OP is actually experiencing clutch slippage?
I took his problem to be that he would get to a certain speed when no matter how much throttle he would loose power with corresponding lack of rpm and speed.
Not that the revs go up but not speed.
I think he's having air/fuel mixture issues not final drive ratio or clutch issues.
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- kwak750ltd
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- 650ed
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kwak750ltd wrote: Thanks for all the reply's. The clutch is not slipping as far as I know. And although the rev's in 5th gear are at around 4200 at 45-50 mph. It will pull away even more from 50 up to the max that I have took it to which was 60. But at that speed the engine sounds like it's thrashing it's guts out. Like I have said in past post's. It goes up the gears so quick just like a scrambler motorbike. ( Within seconds from a standing start. ) I will order some new sprockets and a chain to see if that helps. It's ratio at the moment is 2.54. and will change that to 2.43. Will let you all know if it sorts the problem out. Thanks
There is no speed below the engine's redline at which the engine should sound like it's thrashing it's guts out. The engine should rev freely and easily all the way up to redline which in top gear on your bike is in excess of 120 mph. I suggest you have an experienced rider test ride the bike to see if they also detect the engine "thrashing" you mentioned. If they do you need to correct the problem, and changing the sprockets is not addressing an engine problem. Ed
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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