hey everyone i need some help, i have a 1776 with a single weber 40 twin throte and a 009 dizzy and the car runs smooth at idle and between 4000-5000 rpm and between idle and about 2000 rpm but after that it seems to ping, its a really bad tapping noise, it doesn't do it in neutral and if you half throttle it then it starts at 2500 and stops at 3000 then if you full throttle it after that its fine
i need help, any ideas will be good
thanks everyone
trunk monkey, because sometime getting your car back just isn't enough
Everyone has an answer but pinging is caused by
* too far advanced
* too higher comoression ratio
* not enough octane
* stuffed dizzy
pining mostly happens under load. You hear most small korean cars do it taking off at traffic lights - especially if they have only slowed and not stopped.
You get the idea.
The first thing i would do is give it a good tune
Valves, points and timing. In that order
Get a timing light and make sure your 009 doent go past 30 degrees.
Others will say not to go past 32 - others 28.
Whatever get a figure that is the upper limit.
Put higher octane gas in there. Shell 98 maybe
Still doing it???
See what happens
Futue te ipsum!!!
i have already done all of it except the timing light at different rpm. i set it at 0 degrees at idle, could it be jumping 30 degrees during higher rpm, i already use the bp ultimate (98) so i guess it wouldn't be that and i have made the compression higher but i dunno. thanks for the help, ill try the timing light again and see what happens.
trunk monkey, because sometime getting your car back just isn't enough
set static timing to 7.5degrees BTDC.
62/60 model bug eye baja bug, (Full Build in Progress)
1974 Chevrolet Luv
1970 MK2 Ford Cortina GT
1979 Yamaha RX125 Two Stroke tracker project.
2004 Harley Davidson Sportster XL Custom
It sounds like you are leaning out more than anything else.
Give it a good service that will help.
Then go and get some bigger main jets to fatten it up in the mid range and a bigger air correction to take out the extra fuel in the high range that you just put in.
I was going to join the Democrats to keep the bastards honest, but joined the forum instead.
There a lot of details missing before any real accurate advice could be offered. We'd need to know the compression ratio, cam, ignition setup, spark plug type, distributor type and carburation etc...
Assuming you've got standard heads your compression will be close 8 to 8:2 is to one. If you've got dual carbs with any luck you'll also have a mechanical advanvce distributor. You should be able to get away with 15 degrees BTDC at 800rpm idle and 40-45 degrees total advancewith 98 octane.
Most vacuum advance distributors don't work properly with dual carbs. You might also have a leaking vacuum line or a stuffed diaphram in your vac distributor if you've got one... good reason to go with a 009.
I run 18 degrees advanve just off idle with no issues at all. That 7.5 degrees at idle stuff was for back in the dark ages when octane ratings were less than 90... 😀
Dude,ide set the timing like has been said before at 28-30 max advance with a strobe and let the idle advance fall wherever,OR SO IVE HEARD,sorry tooo much merlot and peanuts :birthday
VDubya wrote:It sounds like you are leaning out more than anything else.
Give it a good service that will help.
Then go and get some bigger main jets to fatten it up in the mid range and a bigger air correction to take out the extra fuel in the high range that you just put in.
:thumb :kiss
sorry to hijack but ian im glad u have posted in this thread.
i had beening running about 14 BTDC on my engine with 009 running 98 octane and was told that i would have all these problems by everyone. (problems i hadnt had) and so ive whacked my timing back to 7.5degrees BTDC but i might advance it a bit now.
62/60 model bug eye baja bug, (Full Build in Progress)
1974 Chevrolet Luv
1970 MK2 Ford Cortina GT
1979 Yamaha RX125 Two Stroke tracker project.
2004 Harley Davidson Sportster XL Custom
It could be something else - like a loose nut or tinware or something that is resonating at certain RPM...?
Not much chance of pinging on a 'free revving' engine..
Pay your debts, CxxT
VWCOOL wrote:It could be something else - like a loose nut or tinware or something that is resonating at certain RPM...?
Not much chance of pinging on a 'free revving' engine..
He explicity says
bajaben wrote:it doesn't do it in neutral
So why would he listen to you?
sorry about this but i feel stupid, it is running a single weber, 40dcn and it has counterwieght crank and rods and lightened flywheel, it has recently had a service and has been put on an sensor and is running perfect at all rpm. stock cam, etc. i recently took the large off road wheels off and had to replace them with stock ones and it seems to be doing it only when it is cold. would the timing change under different load conditions and how do you set max advance etc, im not a competant machanic yet but am learning. ( im also not very competant at spelling so forgive the mistakes)
[ Edited on 7/11/2005 by bajaben ]
trunk monkey, because sometime getting your car back just isn't enough
when ur engine is cold u might get more tappet noise are u sure its not this that you are hearing?
62/60 model bug eye baja bug, (Full Build in Progress)
1974 Chevrolet Luv
1970 MK2 Ford Cortina GT
1979 Yamaha RX125 Two Stroke tracker project.
2004 Harley Davidson Sportster XL Custom
If you've got a 009 distributor (no diaphram on the side of it), hook up the timing light and adjust your timing to 34-36 degrees when reving it at 3500. This will ensure the distrubutor is fully mechanically advanced as full advance is reached at 2800-3000 depending on the 009. Running the 009 distributor this far advanced helps eliminate that "flat spot" that a lot of people complain about with mechanical advance distributors. With this advance it will idle around 15-17 degrees btdc.
You can easily run as high as 40 degrees BTDC total advance with 98 octane. I've seen 45 degrees on 10.5:1 CR motors with bp ultimate but I prefer keeping it a little more sane with lower compression engines.
If you've got a stock vacuum advance distributor (round disc on the side of the dist, with hose to the carb)you need to set your idle timing to 15 degrees, and then rev the motor and watch it advance to ensure it is advancing the timing properly. It should go to full advance with the throttle is opened. Don't over rev the engine though. 😀 Safer still , you can also pull the hose off the diaphram that goes from the carb to the distributor. This will cause the diaphram to go to full advance, which can also be 34-36 degrees. If the timing doesn't advance when the hose is removed, this means the hose is split or your distributor timing advance diaphram is leaking.
This should sort you out unless its not pinging.
Other things to check are tappets as Anthiron suggested. Also look for exhaust gasket leaks and check your exhaust nuts are firmly tightened. Slip fit headers like those used on buggies sometimes don't seal all that well and can make some wierd noises too.
