knock knock

[autoguy]

well got ludwijg running and idling, but under power/load he knocks something fierce, he has a new 12 volt distributor, and coil, a rebuilt carb and has been converted to 12 volt from 24 volt, he also has little to no power, my vespa goes faster in first gear

he knocks in gears, 1-3 i don't know about 4th, and knocks in reverse too and i dont think it is the zenith warp, because the air/fuel mix works when you adjust it

me and dad are thinkin it is a burnt valve or a valve spring has come unseated or a valve has become unseated, or worn

he is missing you can feel it in the exhaust, we have not taken off the valve cover yet, that is on sundays agenda

any ideas what could be causing the knock

i had a nice bit of road rage today too and almost ran over a saturn car, would have been his fault though i was cussing something fierce too, the guy thought he was in a hurry as i was backing down a hill on our block and there was a car blocking the other side of the lane, i also realized i had taken my handgun for the ride but not my cellphone, i had fun even though he was not running right

[Firemanshort]

What is the chance of a leaky headgasket allowing blow by and spark share between cylinders? I had one do that to me once. It messed about knocking for a while before it got worse (really worse) and I finally figured out what it was.

[I Leak Oil]

Do a compression test and a leakdown to try to figure out the mechanical conditon of the motor. Knock from engines can be ignition related or mechanical in nature. Start by figuring out which it is and go from there. Removing the valve cover to check the valve train or the oil pan to check the crank and rod bearings is pretty easy to do.
When you find the problem you can cheer yourself up with a good KnockKnock joke!
Jason T.

[S11A]

Jason had a good point about ignition. I am guessing you timed it when you installed the new dizzy, but doublecheck to make sure the dizzy is tightened down, the advance mechanism is working properly, etc.

Does it knock ar all RPMs, or just under load?

Is the dizzy vacuum advance or other?

This is probably the easiest thing to check of all the good suggestions above, so on the day after the St. Patrick's day party, that is where I would start

[greenmeanie]

i also realized i had taken my handgun for the ride but not my cellphone, i had fun even though he was not running right

What were you planning to do? Put her out of her misery if she couldn't get back up the hill?

Cheers
Gregor

[autoguy]

FS, I had not thought about it possibly being a head gasket, I have a new head gasket

J, thanks, I will run a compression check too, LOL about the knock knock joke

s2 it only knocks under load only, it has a vacume advance dizzy

GM, woulda put him out of his missery if I could not have gotten back home nope I had my gun on in the front yard for good measure

[autoguy]

well mother nature decided i needed a break from working on my rover, its raining and is supposed to rain tomorrow too

if i do end up needing a head gasket should i go with the copper or the composite gasket ? i thought i had a head gasket but i looked and i dont

[Momo]

Composite. Torque it once and forget it

[autoguy]

Composite. Torque it once and forget it

thanks, composite it is

well it stopped raining and we ran a compression test, the front two cylinders where showing 70-90 psi with little resistance from the hand crank turned 5 times, the back two pegged at 100 right off (our compression gauge only goes to 100 psi

so i think its off with Ludwig's head and he gets a new gasket

should i order the head gasket set from BP or just the head gasket, valve cover gasket and manifold to exhaust gasket ? it will be $50 for the gasket set but i think that is with the copper gasket

what gaskets am i going to need ?

he does not smoke much at start up, nor does he knock at idle

i checked the dizzy and it was not loose

[S11A]

The knocking under load can be may things, but ignition advance is a common culprit.

Maybe check the vacuum hose for leaks? If it is not new-ish, maybe just replace it.

Also check to see if you have vacuum. If you do not have a vacuum guage, a quick test is to use a small (1/2" x 1/2") piece of paper that should stick to the hose after you pop it off the dizzy and are revving it a bit. That will at least tell you if you are not getting vacuum (something clogged inside).

Also, I haven't worked on a Series dizzy, but on other makes that have advance weights and springs, those can be a problem if they are incorrect.

[Tim Smith]

...i also realized i had taken my handgun for the ride but not my cellphone...

Note to self: Don't cut old Rovers or Vespas off when driving through Kansas City.

My guess is it's the timing but not being able to see the truck run, you might find different.

[autoguy]

s2a,I will check the vacume advance, thanks

TS, LOL I will check the timing again, the notch on the flywheel lined up with the notch closest to the drivers wing when we looked at it, is that where it should line up ? we have not hooked up the timing light yet either, and its raining something fierce today and supposed to rain all day

happy st.patricks day everyone

[Tim Smith]

...the notch on the flywheel lined up with the notch closest to the drivers wing when we looked at it, is that where it should line up ? we have not hooked up the timing light yet either, and its raining something fierce today and supposed to rain all day

To be honest with you, I'm not sure. I haven't taken a timing light to mine in such a long time that I've forgotten which mark is where. You may also find some timing teeth on the front of the motor as well, but again I'm not sure. I usually time it by ear.

...happy st.patricks day everyone

Happy St. Pattys!

[autoguy]

recon i will look in the manual about timing

how do i time my rover by ear ? i have heard of the guinness on the wing trick but have not tried it

[Tim Smith]

Once it's running, it's pretty simple really.

You just loosen up the distributor while it's idling (and you've made sure you aren't having any carb issues) and retard/advance until it runs the smoothest and then tighten it down. Go for a test drive and if it's still pinging under load, go ahead and retard it a few degrees more. Keep doing this till it's right.

Sooner or later you will find the best combination where it doesn't ping under load but still has enough power to get out of it's own way.

Well, sort of...