snippy
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| posted on 13/4/14 at 09:05 PM |
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more crossflow tuning woes
I am using this set up:-
1600 Crossflow with standard cam
Weber 32DGR carb
Accuspark distributor with electronic ignition
I`ve got it ticking over nicely around 900 rpm and it sounds very sweet. The problem I have is when I blip the throttle, it just dies, coughs and
splutters for a second or so. It sounds like it`s being starved because it sounds like it`s sucking air when I blip the throttle. If I raise the revs
slowly it will happily increase but isn`t sweet like at idle.
I`ve got the mixture screw wound out 2 1/2 turns from it`s full in position. My crank pulley didn`t have any marks to set up the timing so I best
guessed but can`t be far out because it ticks over lovely. It also starts straight away when cold and when hot.
So, is it timing issues or fuel starvation?
Does anyone know where the timing mark on the pulley should be relative to the woodruff key slot?
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ReMan
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| posted on 13/4/14 at 09:24 PM |
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I agree timing can't be far out, but nothing wrong with giving it a nudge either way and see if it helps.
Sounds more like fuel, through
Sucky noise can be normal.
Does this have an accelerator pump on the carb?
Has it ever ran correct on these jets?
Could it possibly be cam timing?
www.plusnine.co.uk
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snippy
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| posted on 13/4/14 at 09:29 PM |
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There is an accelerator pump yes and it does move when the throttle is blipped, you can see the `arm` moving. The carb was supplied brand new 20 years
ago together with the newly reconditioned engine. So, it did run back then (1994). Although it`s not run and been laid up for 20 years it`s all in
great condition. I`ve stripped the carb and all the jets are clear.
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mark chandler
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| posted on 13/4/14 at 10:11 PM |
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Engine off, when you pump the throttle you should see the accelerator pump arm move and a squirt of fuel exiting the nozzles, no fuel could be a
blockage or damaged diaphragm.
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Trollyjack
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| posted on 13/4/14 at 10:30 PM |
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I can highly recomend these guys
Linky
For advice and service kits
TrollyJack
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Fatgadget
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| posted on 14/4/14 at 09:39 AM |
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Laid up for 20 years?? Chances are fuel lines in the carb have fured up partially blocking fuel flow......Try another carb!
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snippy
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| posted on 14/4/14 at 08:20 PM |
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Mark, yes when engine off and throttle opened the accelerator pump arm is moving.
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snippy
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| posted on 14/4/14 at 08:24 PM |
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Fat gadget, the car hasn't run for 20yrs. During my restoration I have fully stripped and rebuilt the engine and carb to check internals. Both
were new items just before the car was laid up by previous owner. I've stripped carb again this evening to check all jets and everything is
clear.
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snippy
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| posted on 15/4/14 at 05:59 PM |
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Ok so I've measured where my timing mark is on the pulley in conjunction with the woodruff key slot in the centre of the pulley. The mark is
about 46 degrees past the slot. Can anyone confirm this is about right by measuring another Crossflow pulley? Please!
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Smoking Frog
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| posted on 15/4/14 at 06:20 PM |
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Set the timing before moving on to other things. If no marks, find TDC and work back from there.
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snippy
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| posted on 15/4/14 at 06:25 PM |
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I've done that, having found TDC you always get a 'Dead' area where the pulley will move without TDC moving. I've marked this
dead area to create my pulley mark.
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Smoking Frog
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| posted on 15/4/14 at 06:38 PM |
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quote:
I've done that, having found TDC you always get a 'Dead' area where the pulley will move without TDC moving. I've marked this
dead area to create my pulley mark
With TDC marked on the pulley and the crankcase. The correct timing will be something like 10 degrees (check this) BTDC. This link to a DIY degree
wheel may help.
http://www.britbike.com/forums/ubbthreads.php?ubb=showflat&Number=10243
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britishtrident
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| posted on 15/4/14 at 06:47 PM |
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quote:
Originally posted by snippy
There is an accelerator pump yes and it does move when the throttle is blipped, you can see the `arm` moving. The carb was supplied brand new 20 years
ago together with the newly reconditioned engine. So, it did run back then (1994). Although it`s not run and been laid up for 20 years it`s all in
great condition. I`ve stripped the carb and all the jets are clear.
You need to check the accelerator pump is actually squirting.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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threadbare wallet
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| posted on 15/4/14 at 06:53 PM |
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Have you got the acuspark plugs and leads? They are junk! They caused no end of problems with a simliar set up on my xflow,replaced them with ngk
plugs a copper leads and it ran and ticked over so much better and could rev out with out stuttering. Maybe worth a check.
Very few things are "really" needed.
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snippy
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| posted on 15/4/14 at 07:43 PM |
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The accelerator pump is squirting yes
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snippy
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| posted on 15/4/14 at 07:46 PM |
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I'm using a complete Accuspark set up - coil, dizzy, HT leads, plugs. I hope it's not their HT leads that's the issue. I've
used some spark testers whilst the engine is running and they do show good sparks. Hmm ????
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threadbare wallet
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| posted on 15/4/14 at 08:31 PM |
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If you have the splitfire type multi pronged electrode plugs sling them in the bin at least they really are rubbish,i did a test in a rig with normall
plugs and was amazed the thing was running at all! They were barely sparking on one pos two of the electrodes and they were so weak as to be hard to
see where as when i put standard ngk(very cheap of amazon) on with the same gap etc got a big fat spark that had direction! Then i changed the
leads....which had a actual staple shoved in the end to transmit the power to the cap and sorted all my ignition problems! The dizzy end seems ok but
will be changing that as soon as pos as well(it all came with the car) as dont really trust the quality after seeing the rest of it.
At least change the plugs they were about £6 from amazon or most motor stores.
Very few things are "really" needed.
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chris_smith
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| posted on 15/4/14 at 08:36 PM |
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going to throw a curve ball in here, as I had a problem with a 1300 xflow few years back, couldnt find the solution, changed pretty much everything I
could, then to find I had set the valve clearances when cold but not when hot, caused me no end of problems.
link to my thread
sometimes it the simple things?
The secret of success is to know something nobody else knows."
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snippy
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| posted on 15/4/14 at 08:51 PM |
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You're right re setting valve clearances on a hot engine for the 1300. The 1600 engine needs to be cold to adjust them according to Mr Haynes.
Good idea though thanks.
Just swapped Accuspark HT leads for some old HT leads I have but problem remains. I will try some different spark plugs and see if that makes a
difference.
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Oldaker
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| posted on 18/4/14 at 08:09 PM |
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Wind the mixture screw in a bit. Mine did this and I found weakening the mixture fixed it. On my engine. 2 1/2 turns out was too much
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alfas
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| posted on 21/4/14 at 06:57 AM |
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if valve celarance setting does not bring any result i would check the jetting of the carb.
you said "the carb was bought new"
this could be the reason: a new carb comes jetted for a certain application which does not match with your engine.
e.g.: original ford jetting was setup with a proper airfilter, seven-type cars run different filters and should be jetted accordingly.
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snippy
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 posted on 27/4/14 at 08:57 PM |
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Thanks to all for throwing in suggestions. I`ve stripped carb and measured float heights, rechecked valve clearances, checked fuel flow, checked
timing etc etc. So,after much head scratching I bought another new set of standard HT leads from my local motor factor and some new NGK spark plugs.
Fitted the new leads and plugs tonight and there is a marked improvement. My strobe light is picking up a better signal from no.1 lead now too so the
new Accuspark HT leads I bought must have been the problem all along. Very annoyed about this! It`s running so much better now. Couldn`t test drive it
tonight due to it raining but I feel sure it will be better now. Just goes to show you, sometimes basic OE parts are all you need!
Thumbs up chaps!
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alfas
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| posted on 28/4/14 at 08:01 PM |
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the pick-up for the strobe lamp shouldnt worry you:
i purchased some, rather expensive, HT leads and after installing i could not use my strobe light anymore...but!!! everything else improoved...
means the strobe light isnt an indicator.
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BaileyPerformance
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| posted on 28/4/14 at 10:32 PM |
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quote:
Originally posted by alfas
the pick-up for the strobe lamp shouldnt worry you:
i purchased some, rather expensive, HT leads and after installing i could not use my strobe light anymore...but!!! everything else improoved...
means the strobe light isnt an indicator.
Check your HT leads are resistive type, NOT copper core.
Also, you must use resistive plugs with electronic io ignition.
One comment, from past experience, cheap eBay electronic ignition is worse that a well setup points system.
Also, check your dizzy for wear - these engines are old and aftermarket dizzy's can be poor.
Best option is megajolt.
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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threadbare wallet
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| posted on 29/4/14 at 05:25 AM |
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Whats wrong with copper core leads?
Very few things are "really" needed.
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