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CR750 Running (or not running!) issues

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philward:

--- Quote from: moorey on November 24, 2018, 10:39:15 PM ---Have you done a compression test on it.

--- End quote ---
No not yet but this problem has happened suddenly and all 4 plugs wet + thought it's unlikely that valve/bore problem on all 4 pots

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Moorey:

--- Quote from: philward on November 24, 2018, 10:48:54 PM ---
--- Quote from: moorey on November 24, 2018, 10:39:15 PM ---Have you done a compression test on it.

--- End quote ---
No not yet but this problem has happened suddenly and all 4 plugs wet + thought it's unlikely that valve/bore problem on all 4 pots

Sent from my Moto G (5) using Tapatalk

--- End quote ---
It is. Its just that you have stripped the carbs looking for bits of pods, I suppose its possible for it to have got to and stuck to the valves/seats .Unlikely but a possibility. Stranger things happen at times.

MarkCR750:
Hi Phil, which carbs are you running, PD41’s with an accelerator pump?

philward:

--- Quote from: MarkCR750 on November 27, 2018, 09:34:46 PM ---Hi Phil, which carbs are you running, PD41’s with an accelerator pump?

--- End quote ---
Early 750 carbs (screw top type) Mark

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MarkCR750:
Ok, mine started to get difficult to start, I found that giving the throttle a couple of sharp twists to make the accelerator pump squirt fuel into the intakes and then pressing the starter button regained instant starting, I think maybe my primary circuit is blocked, really must get around to taking carbs off and sorting, obviously you can’t try that because you don’t have an accelerator pump.
First I would try new plugs because it’s easy, but I think you’re issue could be fuelling , so I would..
1. Check the choke mechanism is working correctly
2. Check float heights and check that floats are not Punctured
3. Check the needle valves are seating/operating correctly
4. Check the carbs are receiving fuel from the tank and the tank isn’t forming a vacuum.
5. Give the carbs another clean.

Then, check the inlet rubbers for leaks.

Then alter your float heights away from the standard setting, if it gets better or worse you might be on to something.

Then because my bike ran badly with Pods until I grafted the original intake trumpets onto the front of them which makes me think pods are a bit crap I would get some velocity stacks, this doesn’t fit with your problem suddenly appearing but I think you’ll find the bike generally runs better with stacks, plus they look nice!

Also check your timing with a strobe gun so that you know the advance/retard is working

It will most likely be none of the above of course 🙂

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