Octane Booster & Timing Question & The Story & Over It.

[Tom H]

No. They make noise when the load is removed, even a smidgen. (technical term)

Then it appears not to be a rod bearing. If I let off a "smidgen" it's a quiet as a church mouse. Back on a "smidgen" and the noise is back. Drop down from 4000rpm to 3500rpm and hold, and the noise is gone.

This would make a great city engine, I was after an engine for the open road.

Thank you again!!!!
Tm

[MattP]

I guess drain gas tank get a gall of high octain race gas. ride it if no change well its mecanical I did have a few pushrods come apart steel ends com loose easy to check. other wise wrist pin bush to check rock wrist pin back and forth. If it is the bushings what I would , did do install bushings and have them borerd so both centers to center are the same. also it is the absolut best surface finish.

[Tom H]

I did check the push rod ends. They feel tight, could not move them with my fingers. I checked the small end pins and bushings when I put it together originally. They do not rock at all. I may be pulling the heads again, if so I will check the pins and bushings again.

I wanted to really thank everyone who has made suggestions!! I have tried many of them already, but always worth being reminded to check, even if I do the check again.

This is just a really frustrating issue. If it made the noise at ALL RPM, then it would be easy to find the problem. It sounds perfect, until I get to right about 4000rpm and then above.

The only constant thing that makes any changes is to retard the timing. Yes, I have made sure the timing marks are correct so many times hoping that I would find I didn't get it right. Even if the arrow on the fly wheel was off a bit from the factory, I have also checked TDC with a chop stick in the spark plug hole. All marks line up right with the stick.

Thank you ALL very much again!
Tom

[Chuck in Indiana]

I chased a "mechanical vibration" for entirely too long. Eventually balanced the rotating assembly, etc. Nada. I became really good at crabbing that sucker. Eventually found it was a tweeked crash bar that was doing some kind of sympathetic vibration at a certain rpm. 

[Tom H]

Chuck, I have looked for that type of thing. I will keep looking just in case.

I even pulled the front end off. Years ago I had a rattle in my Ambo or Eldo. Turned out the fork spring was rattling, I think?

Tom

[pressureangle]

At some point, you look at everything and say 'nothing shows damage' and drive on as is. Crash bar vibration, fork spring vibration, alien elves- all these things are possible and impossible to discover so if it ain't hurt, it ain't hurt.

As a last simple check, it is unlikely but possible that it's a lean condition; check that the needles in both carbs are in the same slot, if not raise the low one. If they are, raise them both one clip and see if it helps. <shrug>

[kirby1923]

etc.

 Nada. I became really good at crabbing that sucker. Eventually found it was a tweeked crash bar that was doing some kind of sympathetic vibration at a certain rpm. 

Sorta like "aerodynamic", flutter..ha!...BTDT!

[AJ Huff]

I'm not mechanically inclined but what I keep reading in the two year saga is the same suggestions over and over, the same results over and over, and no improvements. At this point the problem solver in me says it's  either the most obscure possible condition in the engine or it's not the engine. I lean toward the latter.

One thing I see over and over is that your noise relates to rpm. You've created it in various gears but at the same rpm. That also means it's not a speed issues. So maybe the timing is a red herring.

So what if you focus on rpm not timing? Where does that lead?

-AJ

[Chuck in Indiana]

Sorta like "aerodynamic", flutter..ha!...BTDT!

Lucky you lived through that one..   

[Tom H]

AJ, you made good points.

I decided to buy the Lucas octane booster. I'll take the bike for a ride in the next few days and see if it did anything. If it did, I'll be hitting up Steve for his spacers.

If it didn't. I'm going to pull the cylinders and rods. I'm sure the rods are straight and the bearings are fine. But I will check them again. Maybe I'll install the spacers while I'm in there if I buy them.

Then if I don't find anything and the noise persists, I'll pull the POS, grab the useables, and dumpster the rest. Maybe grab a 1100 or just put my 750 back in. At least my 750 would roll along at 70. Though it always seemed like it was revving high compared to my Eldo.

Thanks,
Tom

[Tom H]

So here's where I'm at.

Added the Lucas Booster. Mixing ratio was a bit confusing. No clear instruction on bottle except that it treats up to X gallons. I went with the ratio on O'Rielly's site. 1oz per gallon. Full tank added 6oz.

Seemed peppier, probably just me?? Went on one of my freeway test tracks. One way has more flat to downhill, back is more flat and uphills. Timing was at 2deg.

Going: "Almost" seemed like less noise. Ran as usual. Hold throttle flat to uphill, noise. Downhill, noise gone.

Coming: I "think" the noise was worse than before the Lucas. The kicker was when I got off the freeway and about 2 miles of city, I stopped at a store for a few minutes. When leaving I felt like I wanted to get up to s[peed a little more briskly than usual for S+G's. Right about at my shift points for 1st through 3rd the noise was there and loud, only need to go to third and then turn to a side street. WTH!!!

Day 2: Adjusted timing to 0deg. Ran the same route. Much quieter, but noise still there. Stopped at the same place on the way back and tried to pull away like I did the day before. No noise this time.

I think I'm may just to have to give up on it for now. If I want to do a road trip it will be my EVT or HD. Both will roll along at 70+ all day. The HD will do 80+ all day.

I just don't get why at 65mph/~3500rpm or less it sounds PERFECT!!!!!! Just FN PERFECT!! Going slightly downhill holding 4000 RPM it sounds PERFECT!! Ever so slightly let off throttle on a flat or uphill while still at 4000, PERFECT!! Roll back in the tiny bit, BAD AGAIN. But get a hill or a headwind on a flat, it sounds like something like a valve is going to come apart.

I also wanted to say that the sound is NOT the typical "ping". My Eldo 850 does get the "ping" like popping/ breaking glass (probably needs a decarb after 15 years or more and who knows how many miles).

There was an offer for the spacers and a mention of that it helped. I'll PM  to see if the offer is available. Then when I'm in the mood to install them, I'll see if the spacers fix my problem. Since the jugs will be off, I'll look at both ends of the rods.

Well, thank you all very much for all the suggestions. I have been chasing this for WAY too long.
Tom

[Huzo]

Excessive glowing carbon deposits on the piston crown can lead to pre ignition. It can fire the mixture too early.
This is different to detonation, which is the uncontrolled burn rate of the mixture.
If you have an excess of carbon causing the ping, it will generally reduce or cease when you roll off the throttle, thus reducing the CHT...(cylinder head temperature).

[Tom H]

Huzo,

The 1000 was opened and cleaned many times. There has been no carbon build up while I have been trying to solve my problem. My 850 could be carbon build up.

Thanks for the thought!
Tom

[Huzo]

Huzo,

The 1000 was opened and cleaned many times. There has been no carbon build up while I have been trying to solve my problem. My 850 could be carbon build up.

Thanks for the thought!
Tom

Our little postie bikes used to routinely need a piston de carbon at 16,000 k.
They would ping their gutses out in hot weather until it was done.

[Tom H]

I'm thinking that is my 850's problem. It's on my list of "to do's" and have head gaskets ordered, may have new valve guides done since I have the heads off.

Tom

[NCAmother]

Don’t give up, I’m I a similar situation and it feels shitty.  With that said, can you measure spring pressure?  I wonder if it’s valve float.

[Huzo]

Don’t give up, I’m I a similar situation and it feels shitty.  With that said, can you measure spring pressure?  I wonder if it’s valve float.

It probably doesn’t help, but people here care...a lot.
I am really looking forward to the wash up on this. I did two back to back Melbourne-Sydney runs this week in the truck.
1000 km each way=4,000 km and I was thinking of your issue a HELL of a lot of the time.
Each time I stopped for a mandatory rest break, I checked the forum and although your side of the world was in night time darkness, I was amazed at how many replies you were getting.

[TOMB]

I've read all the posts here I didn't see anything that indicated that you actually check the advance Springs it may be stretched and it doesn't come into effect until you write that 4000 RPM range which would probably be full Advance on your engine anyway just a thought

TOMB

[Tom H]

Tonti heads springs: Bought a valve spring gauge and tested the springs per the Guzzi manual. This gauge you mount in a vice or arbor press and then measure the length of the spring per the specs in the manual and read the pounds. All tested maybe 5# less than the max spec in the book. Seemed acceptable to me. Also checked the installed spring height, provided I did that right, hoith was fine. Also spring free length was correct per the book.

I was thinking valve float as well, that is why I tested the springs.

Dist. springs: I do not know how to "test" the strength of the springs. I would guess the only way is to watch how the timing advances per rpms.

Dual point dist. W/Dyna 3 and Bosch Blue: Used set of stock springs as well as new performance (fitted mainly to big valve engines, slows the rate of advance) springs. Neither set fixed my noise when timed at 2 or 0 deg. Performance springs caused a loss of power in the low end but did hold back full advance until over 4000 rpm.

Single point dist.: Used set of standard springs from Harpers both loop/loop, don't remember the coil count. Also tried a new standard set from MG Cycle, 1 loop/loop and 1 loop/oval. No change with either set. Low end power was fine though with either set.

Guzziology has a nice chart of advance curves with different springs. Tried the performance springs because it would hold down full advance until about 4200 or 4300, can't remember which.

The closest I have come to eliminating the noise is with the timing at 2deg After TDC. I lost a fair amount of power this way.

Lets also see: New plugs (BP6ES or BPR as normal, BP5 as well as 7), 2 sets of wires as well as end caps. A used Tonti small coil set as well as new Bosch blue with the dual point.

I have tried to find ANYTHING and everything that could be vibrating. Nothing, except I found my gen belt was rubbing the upper belt cover mount. Even removed my horn and gen, went through the forks, put my foot on the side stand, ect..

Also thought it might be a crack in my headers or exhaust leak at the gasket. Using Tonti heads with Loop headers and 2 gaskets, tried to sets of headers. Changed to Loop heads and 2 sets of headers. No change.

As a refresher, I do have the valtec type chain tensioner and a new cam chain. Also made the noise with a stock manual adjust tensioner.

This is why I feel I'm over it. There is a noise coming from somewhere caused by something. Timing affects the noise, but could also change how the engine naturally vibrates I would guess. More timing more and earlier noise, less timing less noise. I really don't want to run at 2deg Atdc. Nor do I feel like tearing the engine down to a bare block and still not find anything.

Yes, I have made sure my marks are correct every way to Sunday.

Even thought I could have the wrong cam. Took a degree wheel and followed the book on how to check valve timing, should be the correct cam. Also tried to check valve lift with a dial indicator. I compared my lift to the lift of a correct for this engine used cam. They matched.

At some point I will try the cylinder spacers. and see what happens. If it doesn't fix it, does anyone want a great 1000 engine for a city bike

Tom

[Tom H]

I added the spacers and times it at 2deg. Went for as short test ride and it may have helped a bit. I need to do my longer test tracks to know how much of a difference it actually made.

I also looked at the rods since I was in there. I do not have a real good way to measure the small end ID. Removing the piston and just using the wrist pin, it felt fine. I could not feel any slop. I don't think I wold have measured accurately enough to tell how much wear they had. My 850 had wrist pins you could wiggle, I don't believe it made any noise. At least not like the 1000 does.

I also confirmed again that if I keep it at about 65mph in 5th or less, it sounds great. I would guess that's about 3500rpm. On the streets in lower gears and about that rpm, it sounds great as well. I guess that's why I could never understand a rod end being bad. Seems like it would act up at any rpm? (shrug)

Tom

[guzzisteve]

I would think w/shims at .020" it would not have any ping from ign. Your squish just got bigger. I'm not a math & science guy but maybe 8 1/2-9 to 1 comp.

[Stretch]

Another thing:

Have you checked your fuel petcock/filter?

Could be that you're running fine at small throttle openings, but
lean at larger throttle openings. could be making it ping?

Just a thought.....

Please keep us informed - I'm really curious!

                                               -Stretch

[AJ Huff]

Maybe it's not engine noise but transmission.

-AJ

[Tom H]

Took it out on my test track today. I do think the shims helped, about 75% or so better...SO FAR. More riding needed to confirm this.

Fuel idea isn't a bad one. I don't think they are clogged. The in-tanks are fine, might look at the carb filter. I had been running a universal inline filter. Removed it since I was thinking the same about running lean. I did try one time running on both petcocks, didn't change the noise.

Thought about the trans.

As I have mentioned, more timing = more noise. I'm at 2deg since adding the shims. I think if I adjusted it to 0deg, the noise "might" be completely gone. I need to ride a bit more and see how it does.

Thank you all again for the thoughts!!!!!
Tom

[AJ Huff]

Maybe you just need better better plugs.

-AJ

[Tom H]

Ear or spark??

Tom

[AJ Huff]

Damn autocorrect. Maybe you need better ear plugs. 😀

-AJ

[guzzisteve]

Did it blow up yet Tom? Just wondering what happened on more miles.

[Tom H]

Welllll..... I need to ride it more. After installing the shims I thought it had improved it on my first ride with them. Then on the second ride in warmer conditions, seems like it didn't make a difference.

I have been riding my 850 Eldo. The 1000 has more low speed power, but I could swear that the 850 has more get up and from ABOUT 65mph. No dyno data to prove it, just my feeling.

I'll ride it more and see. Right now I think it will make a nice city engine compared to my 750 Ambo with the 4 speed box. Always hated the 1st to 2nd shift of the 4 speed.

I love my EVT for how it runs. It "should" be my long distance bike. I had a tip over in a parking lot a while ago. I had to have help to pick it up, at least to do so quickly. Maybe I need to make my Tavern to Tavern "style" HD my long distance bike. It's low CG makes me think it I did tip over, I could pick it up.

AAARRRGGGHHH,
Tom

[Tom H]

Now that I had my rant.........

I do need to ride it a bit more to confirm how it's doing. Right now, the shims didn't make a significant change.

I think I'm down to the point of having to pull the engine apart and take all the bit's to a "specialist" engine builder to check and measure all the parts. But in reality, I don't want to spend any more money on it.

But again........ If I had an issue with a "part", I would think the issue would be there below the 65-70mph range as well as above. As I have mentioned many times. If I keep it at or below 65mph/4000rpm, it runs really nice and sounds really nice.

Thank you all!
Tom