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Pipes get red near the head #147643 08/29/08 10:23 am
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thebevman Offline OP
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Hello all, I'm reaching out mostly because of parinoia. I have a '66 Bonnie and when I drive to work in the morning, at about 4:30, the first 3 inches or so of the pipes go dull red. Is that normal? I just catch it in the lower throttle ranges from about 1/8 to 1/2. I understand that there is a lot of heat coming out of the cylinder but is it enough to over come the cooling effect

She runs like a champ after she gets warmed up and stretches her legs a bit. Plugs look fine, a bit grey after a good hour + cruise. Got a Boyer ignition and it's right on the money. Mk 1 930's that have been bored, #2 slide sleeved to match, 105 needle jet and 200 mains. Also, she's got a later set of pipes, with the balance tube


'66 Bitsa Bonnie
Boatload of Hodakas

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Re: Pipes get red near the head #147644 08/29/08 11:18 am
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triton thrasher Offline
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I don't think they should get quite that hot.

I think it's slightly suspicious that your needle jets are slightly small compared to the usual 106. Weak mixture leads to excess heat.

First I'd try the needles in a richer notch. Just to see how it runs.

It's never a bad idea to tune the carb from first principles, as described on the forum, in case your main jet is a bit small.


Amateur Loctite enthusiast.
Re: Pipes get red near the head #147645 08/29/08 12:30 pm
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John Healy Offline
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"Is that normal?"

In a word... No!
j


Re: Pipes get red near the head #147646 08/29/08 12:51 pm
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Phatt Bob Offline
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If your pipes are glowing red, it means the mixture is still burning strongly when the exhaust valve opens.

I would suspect your timing has retarded for whatever reason.

Bob


Phatt Bob
'95 Daytona 1200
'98 Daytona 1200 dragbike
ex-850 T140 Caff Racer, 850 Triton, Morgo T120, Starfire and Pretend Daytona 500 owner
Re: Pipes get red near the head #147647 08/29/08 1:09 pm
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JubeePrince Offline
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I'm with TT on the needle clips...however, I don't think the mains would come into play in the throttle range you describe....

Why are you running a leaner needle jet and richer slide? In the throttle range you describe, the affected carb circuits are slide, clip and needle jet......

Double check the timing....I run Boyer as well....my plugs were gray like you describe. When I examined them with a magnifying glass, I discovered the 'gray' was actually piston material! I have reduced my timing one or two degrees to compensate for the soup they call gas here in the states...

HTH,

Steve


'77 T140J
"Vintage Bike". What's in your garage?

"The paying customer is always right."

Fitting round pegs into square holes since 1961...
Re: Pipes get red near the head #147648 08/29/08 1:11 pm
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JubeePrince Offline
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Quote
Originally posted by Phatt Bob:
... the mixture is still burning strongly when the exhaust valve opens.
Wouldn't that also happen with the burning of end gases during detonation?

Steve


'77 T140J
"Vintage Bike". What's in your garage?

"The paying customer is always right."

Fitting round pegs into square holes since 1961...
Re: Pipes get red near the head #147649 08/29/08 1:12 pm
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Dick Harris Offline
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John,I wish you would stop being so verbose!!!! If the timing is right on,as has been said,I would be going for .106 needle jets. What do you think??? : Dick

Re: Pipes get red near the head #147650 08/29/08 2:09 pm
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John Healy Offline
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Dick: There are other people who can take the torch.

Knowing what one should know about getting the timing disc right on these early motors it would be wise to verify the timing. This, even though you KNOW it is perfect.

I think at first glance, and not having the motorcycle in ones possesion, that Bob has a valid point. Glowing pipes is one of the symptoms of retarded ignition timing.

As far as the needle jet goes, TT and the Bethany Rooster are correct. The standard needle jet for this motorcycle should be a .106."

So what do you think?
j


Re: Pipes get red near the head #147651 08/29/08 2:11 pm
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John Healy Offline
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Oh, if the exhaust pipe is glowing can you imagine what the poor exhaust valve must be going through?
j


Re: Pipes get red near the head #147652 08/29/08 2:16 pm
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btour Offline
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Hi All,

I dunno, but wonder if the timing is the culprit, then perhaps if checked using a timing light, there maybe a loose rotor giving a false reading? I don't know how one checks for that. I know mine was loose, and it seemed to jump a bit on the light.

I remember that my right side glowed red when starting, and that is the side that blew the piston. But that red glow went away when I reset the valve lash. If I remember correctly it was too tight. It was many many miles later the piston went.

Perhaps check the rotor, to affirm timing, and check valve lash, then do carbs. RE-sleeved carbs tend to run rich, as I remember reading.


Bob, Lifetime bike: '71 T120R, bought in '71 at Ken Heanes, England.
Re: Pipes get red near the head #147653 08/29/08 2:31 pm
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John Healy Offline
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Dick: There are other people who can take the torch.

Knowing what one should know about getting the timing disc right on these early motors it would be wise to verify the timing. This, even though you KNOW it is perfect.

I think at first glance, and not having the motorcycle in ones possesion, that Bob has a valid point. Glowing pipes are one of the symptoms of retarded ignition timing.

As far as the needle jet goes, TT and the Bethany Rooster are correct. The standard needle jet for this motorcycle should be a .106."

So what do you think?
j


Re: Pipes get red near the head #147654 08/29/08 3:04 pm
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thebevman Offline OP
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I was suspecting the needle jet position. I'm running 105's because when I was dialing in the carbs the 106 was too rich in the lowest notch. The #2 slide came with the bike and I run it because it's worked so far and because the cost of getting one sleeved to fit the motor. I also have a '68 rotor on it so I can strobe time it. I thought the motor was getting a bit hot but from what I've read on this board these motors tend to get hot anyway.

As soon as I get the chance I'll double check the timing and try another needle position. Thanks all.
Gotta get It's date night and shmbo is on my a&^.


'66 Bitsa Bonnie
Boatload of Hodakas

Re: Pipes get red near the head #147655 08/29/08 4:12 pm
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spook Offline
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Golden Rule Bevman. Only do one change at a time,then test.

Re: Pipes get red near the head #147656 08/29/08 5:03 pm
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kommando Offline
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'I was suspecting the needle jet position. I'm running 105's because when I was dialing in the carbs the 106 was too rich in the lowest notch.'

You should only move to the next smaller needle jet if the bike in mid throttle runs rich with the clip in the top notch position. The lowest notch postion will give the richest setting for a needle jet as the needle is in the highest position and flows more fuel, the highest notch will give the leanest postion.

Re: Pipes get red near the head #147657 08/29/08 7:58 pm
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Jack Adams Offline
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A very common mistake when dialing in sleeved amals is to re-install the old needle jet which is most likely worn as much as the slide was.So I'm with Bethany Rooster,.106 needle jet. Jack AKA Indiana Rooster

Re: Pipes get red near the head #147658 08/29/08 8:28 pm
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don1 Offline
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Im with J.P.on this one.If it's getting hot enough to make steel glow then it's almost certainly hot enough to damage aluminium.I would replace the needle jet with a 106 and recheck the ignition,making sure that the timing mark on the rotor is in the correct position and the rotor is tight. Don. TT600.


don1
Re: Pipes get red near the head #147659 08/29/08 10:21 pm
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az-idea Offline
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..most likely need the 105 to choke down the too rich slide and aquire decent midrange..sure it'll work that way till you spring for the appropriate slide..more sure the pipe glow is due retarded timing despite the"certainty" its correct..?..whats your method for getting static tdc to start with..?..

Re: Pipes get red near the head #147660 08/30/08 4:14 am
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aceaceca Offline
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Do not forget to check for something dragging or resisting motion. Brakes for one. Oil in and circulating.

Re: Pipes get red near the head #147661 08/30/08 7:06 am
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thebevman Offline OP
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Kommando thanks for spotting my over site, I did mean in the highest notch. I had the wife yelling at me to get off the computer and take her out to dinner when I was writing that, so I was over come with fear of bodily harm. Now that I have a bit more time I can explain more.

My bike had been off the road for about a year, trying to get it up to German TUV insp. standards on a budget. I got the carbs close enough to get it through the insp. ok. At the time I had a new .106, same slide, and 190 mains. A few weeks later I got the time to try to straighten them out. I first double checked the timing w/ a strobe light, then took all my jets and the AMAL tuning manual I printed out to a deserted back road near my house and tried everything. What gave me the best acceleration and throttle roll on is what I've kept.

Jack- The carbs were re-sleeved when I purchased the bike though you make a good point, one which gave me alot of trouble in the past until I bought a new needle and jet that is.

Don1- I never though of the rotor being loose, I'll give it a check, and it only has one mark. I'll give the Boyer's rotor a check as well, my cams aren't machined for a woodruff key so I use a lock washer.

Az-Idea- As far as getting static timing, I follow the manual, I pull the plugs and spin the rear wheel until approx TDC comes up. Then go through the Boyer's instructions. I'd never heard of re-sleeved Amals running richer.

aceaceca- the only thing that's dragging is my *** and my Toyota's muffler (another story all together). Brakes are fine and I always look to make sure the black gold is flowing.

How much would it cost to get leaner slides sleeved to match my carbs?

Thanks for all your input, I'll give it all a try and let you know my results.


'66 Bitsa Bonnie
Boatload of Hodakas

Re: Pipes get red near the head #147662 08/30/08 11:22 am
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triton thrasher Offline
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Quote
Originally posted by thebevman:


How much would it cost to get leaner slides sleeved to match my carbs?
5 minutes with a file on the slides you have.

Bear in mind you can't un-file the metal back on!


Amateur Loctite enthusiast.
Re: Pipes get red near the head #147663 08/30/08 1:37 pm
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thebevman Offline OP
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TT, I saw that on another post. If I recall correctly you should only remove about 1/32 of an inch.
I'd rather look into another set of slides just in case it doesn't help and as you hint at I f--k up the ones I have.

I re-checked the timing this a.m. and it's spot on. Checked the rotor and the Boyer's rotor too, both are tight. I also dropped the clip from the middle notch to the lowest one, there wasn't a noticeable drop in performance and the plugs looked a bit darker.

When I was dropping the clip I took a look at the slide and notices something I'd forgotten. On the inside of the slide there is a #2 in the recess where the clip sits. On the bottom of the slide where the needle protrudes through is says, "Mike Gaylord Products" and there is a #3 stamped next to it. I'm assuming that Mr. Gaylord is the one who either made or sleeved the slide but what # slide is it?

Tomorrow morning I'll know for sure if the dropping a notch helped.

Thanks all.


'66 Bitsa Bonnie
Boatload of Hodakas

Re: Pipes get red near the head #147664 08/30/08 1:49 pm
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JubeePrince Offline
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Quote
Originally posted by thebevman:
What gave me the best acceleration and throttle roll on is what I've kept.

I pull the plugs and spin the rear wheel until approx TDC comes up. Then go through the Boyer's instructions.
BM -

A couple of thoughts:

1) I don't see any indication of using the state of the spark plugs to discern the tune of your engine (at least with regard to jet testing/plug chops)......does best acceleration and throttle roll mean this is what 'felt best' to you?

Subjective conclusions are no match for an objective plug chop. My bike 'felt' fine, but had I not inspected my plugs closely and sought out some opinions here, it would have been a matter of time before I destroyed my engine....

2) Static timing for the Boyer should occur at 'exactly' full advance (38 degrees BTDC) not 'approx' TDC. I would start there.....

HTH,

Steve


'77 T140J
"Vintage Bike". What's in your garage?

"The paying customer is always right."

Fitting round pegs into square holes since 1961...
Re: Pipes get red near the head #147665 08/30/08 2:57 pm
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bevman, I have Mike Gaylord (WA, USA) sleeved carbs on my T100, and you have a #3 slide there. Go by the stamping on the bottom, not in the needle recess.

A sleeved AMAL will generally run slightly richer than a stock one due to the better fit of the slide. In a stock AMAL, a percentage of air entering the engine follows a path around the slide without mixing with fuel, thus leaning the mixture slightly. As the slide wears, this gets worse, leading to erratic idle where it shows up the most due to the small throttle opening.

Even if your alternator rotor is tight, the timing mark could still be very wrong. I've seen it many times. I've even had one that was tight when cold but got loose when warmed up and the timing mark would return to correct when cold (which is generally where I checked it) but would then move when warm (which is generally where I timed the engine.) So don't assume that mark is correct, it probably isn't. I agree with retarded timing being the most likely cause of red hot pipes.


"Beer is proof that God loves us and wants us to be happy" - Benjamin Franklin
Re: Pipes get red near the head #147666 08/30/08 9:40 pm
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..Ditto Jubee on the"approx"TDC aquired by observation of what appears to be TDC..looking down the rabbit hole..your crank,to which the rotor is attached,can move side to side[cc\cw]as much as 6\8deg while the piston appears to be at tdc by your method..you need to archive for the info on aquireing TDC and 38btc precisely..dont trust any pre-existing marks"for"..correcting the slide by file to get a 3.5 is easy pie..finger nail paint the"line" of material to be removed..you should be able to go to 106nj then with the needle re-clipped center or#2 lean...what plugs\heat range you use comes next....and..there will be chargeing issues to read up on with the Boyer so you know what to expect and how to clear up..there will be a"when"..so be prepared!!..

Re: Pipes get red near the head #147667 08/31/08 2:06 am
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thebevman Offline OP
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J.P., hh, & az, you guys have got a point, one that I really never considered before. The rotor only has one mark and its the one I've just blindly trusted. Now comes the bad news, I have timed this bike this same way and ran it, sometimes pretty rough, for the last five years. I just finished a 230km trip to Hockenheimring.
Now the good news, I'll post the photos for you all to enjoy, later on.

Thank you all for passing the torch here, it certainly looks like I have more work to do than I had anticipated. Should get her finished just in time for winter to set in though.


'66 Bitsa Bonnie
Boatload of Hodakas

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