Ping solution 76 Convert???

[sparrowhawwk]

I'm sure this must have been covered here somewhere but just wondering if anyone has had any success with carb changes or jetting?  Also see Harper's has a gasket set for lowering compression?  Thinking about doing a very basic water/methanol injection?  Starting to think I might have to move the sidecar to another bike if I can't find a solution.  Any help or suggestions appreciated.   B

[rodekyll]

What have you done so far?

[sparrowhawwk]

Installed a C5 ignition.  This includes a better coil with new wires and NGK caps.  Really balanced both sides and reduced vibrations.  Increased power, smoothed idle and improved starting but had no effect on pinging.  Richened carb adjustment and raised needles.  Have not tried re-jetting yet.  K&N filters.  Recently switched to NGK Iridium plugs.  BPR6EIX.  These have allowed me to reduce idle speed and mostly eliminated stumble off idle but no effect on ping.  I run Chevron Premium when possible with an octane booster.  When the weather is cooler and humidity higher the ping is almost gone with the exception of higher altitudes.  As soon as it gets hotter and drier the ping hits with a vengeance.  This has me thinking about maybe doing a simple water injection system.

[Rich A]

Have you checked the timing?

RichA

[Antietam Classic Cycle]

How many miles? If it's around 30k miles, I'd suspect the valve guides being worn. Oil in the fuel mixture drives the octane down.

Have you replaced the "distributor" advance springs? They're 39 years old now and have likely stretched.

[sparrowhawwk]

Timing is spot on.  Tried backing it off a couple degrees but no change.  Advance springs are eliminated with the C5.  I've not heard of the valve guide issue.  Mileage is about three times that. LOL 

[rodekyll]

Those are resistor plugs.  Do you also have resistor ngk caps and resistor wires?

Don't worry too much about the idle timing.  Look to your full advance.  I have no idea what a C5 ignition is, but I'm guessing it's a performance mod -- suitable for a lemans?  If so it's running a lot more advance (~37º) v the 32-ish you'd want.  My numbers might be off, but you get the point.

The valve guide thing is based on detonation or 'pinging' behavior.  Sometimes it's due to a crud buildup in the chamber.  A major cause of that is oil blowing past worn valve guides.

One cheep way to tell is to get a bad-kitty water bottle and spritz a little in each intake.  Allow it to recover and do it some more -- not too much at a time.  You'll blow out nasty smoke and then white.  The combination of steam cleaning and cooling the chamber can blow out the crud.  If it improves things you need to ask where the crud is coming from.

Be very careful with the water.  It raises chamber pressures and can cause damage if you use too much.

Other possibilities are a worn timing chain and/or a worn distributor gear.  Does the C5 ignition include it's own advance?  If so, is yours pegged somehow so it doesn't add to the programmed curve?

That's all I've got at the moment.

[sparrowhawwk]

The C5 is an optical timing unit that checks timing every 4 degrees and is programmable.  Actually it is an upgrade for older bikes and was originally developed for very old HD's.  It has now been adapted to a lot of vintage bikes as well as versions for small blocks etc.  Works wonders in older Goldwings.  Mine has 4 differet curves available at the touch of a switch.  The curve I am running is the mildest and almost identical to the stock curve.  It is also a multi-fire unit firing about three times per firing stroke at all RPM.   It can be seen at C5ignitions.com.
Can't verify the distributor drive gear but I just checked the timing chain and at maximum adjustment it is just starting to show a little slack.  I was planning to change it and use a self adjusting tensioner this winter.  I have an almost new chain and self adjusting tensioner in a spare motor.  Maybe I need to rebuild the heads and swap out the chain and tensioner.

I appreciate all the advice.  It gives me a place to start looking.  B

[dsrdave]

I have an '80 convert with a ural chair.  I run K&N filters.  I've had the pinging issues also (always run premium non-ethanol) std NGK plugs.  I went up to 150 main jets assuming I needed more fuel with the filters and the sidecar.  I was wrong,  I'm back to the 130 mains and backed the timing off to eliminate the pinging.  It runs great and has good power.  I pulled the plugs yesterday and they were a beautiful tan/brown color.  Get the jetting back to stock and back the timing off to get rid of the pinging and I think you'll be fine.  I just went down the same road......Dave.

[sparrowhawwk]

Thanks for that info Dave.  I was also thinking about upping the main jet.  Checking into my plug heat range last night I realized they were not right so I put the stock NGK's back in for now.  I wish I could find non ethanol gas here.  I think I'm gong to do a quick valve job and replace the guides and swap in the new chain and tensioner from my spare motor.

[Vasco DG]

The 'Vert motor is such a softly tuned lump it's quite hard to get it to detonate unless the timing is wrong/much too far advanced.

Do you know if the Pistons are stock? Someone hasn't put an 88mm LeMans set of Gilardonis on it by any chance have they? Have you run a compression test? That'll tell the story.

Pete

[Orange Guzzi]

I tried for months to get the knock, loose valve, ping to go away on the left side of my Convert.  It only made the noise when idling and take off.  One day a guy walked up to me and said, "your bike has an oversize hole in the connecting rod hole where the pin holds the piston on.  He said the piston is slapping.  He was exactly right.  I bought a new bearing and had a machine shop install and bore it to fit the pin.  No more noise.  I have no idea who the guy was, he walked up to me at a gas station and told me the problem and walked off. 

[sparrowhawwk]

Pete   You're absolutely right about doing a compression test.  I need to do that.  I am quite sure the bike is stock but......?

Orange Guzzi   Wow!  It sounds like you have my bike.  I have the same noise but from the right side.  I'm taking mine apart next week  Got to see what's in there.  Only way to know for sure.  Back about 15 yrs. the bike with sidecar pulled a 4 x 8 flatbed trailer from LA to Bellingham with a BMW R11RT on the trailer with no ping.  Had some issues stopping a couple times but no ping. LOL  Thanks for all the posts.  I'll post what I find.  B

[pehayes]

My bet.  You're going to chase this until you pull the heads and redo the valve guides.  After about 35K miles, the guides ovalize enough that the suction stroke pulls a small amount of oil past the intake guide and into the air/fuel mixture.  Relative octane rating quickly goes to hell and the bike pings.  Especially under load.  Especially when hot.

If your C5 ignition handles all of the advance, can you modify the advance curve? Can you get it to hold a few degrees of retard up into a higher rpm range?

Patrick Hayes
Fremont CA

[sparrowhawwk]

Well, after spending the weekend changing the intake gaskets in my Chevy 350 (that was fun) and unlike the last owner actually tightening down the distributor holding bolt LOL I got to play with the Convert some more.                                                           Compression test shows 155 L and 157 R.  I like that.  Harking back to another time helping my father with his old 53 Chrysler, I got out a long screw driver.  Putting my thumb over the handle and the other end on various spots on the cylinder heads I got to listen to the innards whir and tap.  Discovered a slight knock on the left side only.  Pulling slightly on the left throttle cable made the knock go away.  That tells me the wrist pin is probably a little more worn that it should be I think.
With time running out before my trip to Alberta I think my best bet is to have the heads rebuilt with new guides and a valve grind.  While they are off I can pull the cylinders and check the wrist pins and change if needed.  Good time to check the rest of the valve train for wear.  Anybody updated to the newer thicker push rods?  Might be quieter?

[Vasco DG]

If the rattle goes away as engine speed rises it might be worth looking at the camchain too.

[mtiberio]

My convert motor(in my loop frame) will ping when I use my loop distributor (changed gear), but not with the stock. No idea why a 9.2 Comp Ratio 950 should have issues with a curve made for 9.5 CR 850, but it does. Ditto what others say on valve guides, but lots of 'con rod' noises are actually cam chain running on case noises

[acogoff]

     Ran the T3 with a side car and had ping issues. Both exhaust valves eventially were found to be bent. The timing chain still had the stock tightener and had way too much slop. Replacing the timing chain and using a Valtec tensioner and 2 new exhaust valves and exh. guides did the trick. Checking your advanced timing with a timing light after setting the static timing is also a good idea to make sure it is not too advanced for some reason.

[sparrowhawwk]

My cam chain is at the end of it's life also.  I am going to swap out the almost new chain and Valtec tensioner from my other motor while I'm at it. 

[sparrowhawwk]

Swapped in the new timing chain and Valtec tensioner.   While I had the one cylinder off to replace  a wrist pin I was surprised to find quite a lot of carbon in the head and on the piston.  My bike works hard pulling a sidecar so I didn't expect that.  Will have to do the other side later.  Discovered that here in BC Chevron now sells a 94 octane with no ethanol.  Ping gone!  Been running my C5 ignition on the lower performance #4 ignition curve which still gave me a good performance increase.  Now I'm running on #2 curve with only the occasional switch to #3 in extreme or high altitude circumstances with no ping issues.  I'm sure without the sidecar load I could be using the #1 with no problem.  One more (third) re-torque to do before I leave.

[sparrowhawwk]

 Aside from taking out a driveshaft along the way the old Convert did well for 1800 miles including climbing the Rockies twice.  Final ping solution was cleaning out the carbon from the combustion chambers and finally being able to get some 94 octane ( 91 in Alberta ) with no Ethanol in it.   

  Next project over the winter is to change out the motor for a 2000 EFI 1100.  I like the bike too much to change but some extra power will help pull the sidecar with a little less stress on the motor.  Always fun to learn new things. 

[rodekyll]

That's the mill in my '76 Convert.  When you get it installed you'll say "Yeah -- that's the sh!t!"  It's the way it should have come from the factory -- low range pulls strong to 85mph.  I have no idea where the top end is in high range.  With the 1100efi I don't need low range for anything.

[sparrowhawwk]

That's the mill in my '76 Convert.  When you get it installed you'll say "Yeah -- that's the sh!t!"  It's the way it should have come from the factory -- low range pulls strong to 85mph.  I have no idea where the top end is in high range.  With the 1100efi I don't need low range for anything.

Mine's a 76 also.  Might have to ask a few questions when I get started on it.  Thanks for the info.  Have you posted your build anywhere here?

[rodekyll]

Nothing to post about really.  I 'convert-ed' it, stuffed it in and plumbed it up.  I used the oem tank with an external pump and the fuel regulator n the right side petcock spigot.  I spliced in the efi section of a Jackal wiring harness and changed the voltage regulator.  It's been flawless and satisfying.

[sparrowhawwk]

Sounds easy enough.  I bought a complete 2000 so I have all the bits and wiring.  I think I read somewhere you lightened the flywheel on yours but I won't for now because of the sidecar.  Sure will be nice to be able to stay out of low more.  Last trip coming west out of Red Deer the long climb over the Rockies had me in low for three or four hours to hold 60mph.   Can't wait.  Thanks

[rodekyll]

I put the heavy flywheel back on the engine for the trike project.  No need for performance parts on a tug.