Topic: CB550 Cafe build - 1st bike build, but not 1st build

[Tintop]

It's been awhile since I posted to the thread, so a quick update.  To preface, the shop is an hour drive from home/work, so all this has been happening over the phone.

The bike is in to have the jetting fine tuned with an EGA (dyno is down).  1st thing that went wrong was the clutch packed it in.  Acted funny during loading, no go on arrival.  After 4 new steels to replace the warped ones (), and different springs, it works like it should now.  Can't understand how there were warped steels, as they were all checked during the rebuild.  Thinking is the springs were wrong, but.....

Once all that got sorted out, it was found that the bike was now running on only 3, #2 was dead at idle.  Huh? These carbs have been off, and apart numerous times, now what?  So off come the carbs, their cleaned again, and this time they also find that the #2 & 3 pilot screw tips are bent.  I know who had them off last, they won't be touching them again.

Now comes the interesting part, its running very rich at idle.  The slows are #42's, with a slight mod.  This is stock for a 78K with PD's (38's for a 77).  All things being equal with the filter, and the pipes (no baffles) it should be lean.  The tech wants to go to 38's, but I pulled the stock slows from my PD 46C's.  Why you ask, because when I was checking them I found the extra set of new #42's.  They are Keyster's , and look bigger than the #42 Keihin's from the 46C's.  The Keihin slows are currently enjoying a spa night in the shop's ultrasonic.  Tomorrow AM they will size them, and try again.  Currently there are 115 mains in, and it looks like they may be close.

Hoping to have it on the road for this weekend.  Quick trip Saturday to check every thing out, then a ride out to Famous Sam's Sunday for the CVMG / GPR breakfast meet.  Following weekend is Mosport.

[Syscrush]

This is at Cycle Improvements? Sounds like they're taking good care of your bike and hopefully getting everything dialed in...

[Tintop]

This is at Cycle Improvements? Sounds like they're taking good care of your bike and hopefully getting everything dialed in...

Yes, I've been dealing with Jim.  At this point I'm sure they love having it there, but not so sure my bank account will like the end result.   That said, they have sorted through the issues, and it looks like things should be finished tomorrow.  I did P/U a set each of #38 & 40 slow jets from Sirius, and then dropped them off to Jim tonight.  It was either 3 hours of driving, or not have the bike for the weekend.  It seems when the Keihin 42's were clean, and then checked with the Keyster 42's, they were the same size.  Hence the requirement for the smaller slows to deal with the over rich at idle to 1/8.  Jim thinks the problem comes from the air corrector sizing.  The 77 PD's have the smallest.

[Syscrush]

Cool.  My experience with them was small/short, but good.

[Tintop]

Rec'd the hard weld rockers from MikeR.  He said they looked great and they do.

MegaCycle cam, slotted sprocket (from MikeR as well), and the rockers.



Close-up of the rockers



These will all be installed and dialed in after Mosport. 

[bwaller]

That's doing it up right. What's the Megacycle grind?

[Tintop]

That's doing it up right. What's the Megacycle grind?

The cam is a 126-00 - a basic street torque cam.  Also allows me to keep the stock springs / valves / keepers.  It won't do anything (little anyway) for topend, but mid range should bring a smile.   Any extra breathing will come from the filter/stacks & pipe(s).  A stage 1 cleanup by MikeR would probably bring it really to life, and add a few more ponies.  Possibility for the winter.

[Syscrush]

Also allows me to keep the stock springs / valves / keepers.

Admit it, you want titanium keepers.

[cwchan]

I saw this bike today.  I went into Cycle Improvements to see about repairing an exhaust and there was Tintop's bike.  I agree that its rather expensive there... but i guess people are willing to travel from all over Ontario to have Jim work on their bikes he must be good.  And he's only 5 mins away..

[Tintop]

Got the bike back tonight.  Kind of a good news / bad news thing.

Good news is the jetting is now very close, and the bike sounds great.  How good?  Jim took it for a final road test, when he was a block away, and hit 8K it sounds just like the videos of the Honda race bikes.   Makes those CBR's with the carbon cans sound like whimps.    

Feeling is it is still too rich in the 1/8th to 1/4 throttle area.  The suggestion is to either return the needle to the stock clip position, or drop it back a 1/2 notch.   The battery was almost flat from all the idling, short runs, starts, so an ignition issue cropped up.  A quick charge helped, so the battery is on the tender.  The bike really needs some road time, then a '3000 tuneup', and a final check of the jetting.  I'll change the needle height before then, as I now have time (see below).

The bad news.  Won't be riding it this weekend, and at best (unless I'm very lucky) it will be a non-runner @ Mosport.   What happened was the threads holding the remote adapter plate to the engine striped.  The bolt pulled out presumably from the oil pressure against the plate.  The attachment was a two piece design.  A hollow threaded piece that fit in the block, with return oil holes, and internal threading (at the top) for the attach bolt.  Seem the internal threading wasn't sufficeint for the pressure developed.    Luckily the bike was standing still in the parking lot, and it didn't happen on the road.  We were checking the ignition because of an intermitant miss (residual battery issue, or ignition, wires maybe?).  Jim rev'd the engine, and I was looking right at the plate when it blew off.  Shut it down instantly, but the top end didn't get oil for about 5/10 seconds.  Guess I find out if there is any damage when I go to change the cam.  Should be OK though.  I had spoken with Terry when he was making a 'Mk2', and suggested a different bolt design.  Time to upgrade.

I'll post some pictures tomorrow, after I have had a chance to remove the parts, and clean everything, that was already clean.

[Syscrush]

Sorry to hear it, brother.  Is this going to take more than some heli-coils to fix?

[Tintop]

Sorry to hear it, brother.  Is this going to take more than some heli-coils to fix?

It will require re-machining of the plate to accept a revised bolt.  The pictures later today will make things clearer.  Worst case it will require a revised plate.

[Tintop]

Back from taking things apart, and the point of failure is very clear, photos below.  Question is why it failed.  My quess is in tightening everything down the soft brass started to fail at the return holes.  Then the vibration, and pressure from the high rpm run finished the job.

The pipes stopped the plate from going very far, and limited the mess.


Point of failure.


The other 1/2, still bolted in place.


Failed part.


The next question will be how to resolve the problem.  A new piece in steel would probably work, but the chance of a similar failure would always be there.  Will need to take some measurements, and see how much room there is to make the fitting a larger dia.

[Honda Brat]

First time I have had a read and look from the start of this thread.  Tintop I take my hat off to you sir that is one exceptional build.  I have built a few bikes, 2 from scratch and currently at the beginning of a CB500/4 build.  I know how much works goes into getting everything right.  I was going to stay pretty close to the 70s style on my build (custom, mild brat style) but after viewing some of your mods it got me re-thinking    Shame that the oil filter didn't work out too well, the vibes on my Harley chop that I have not long  finished caused so many problems and hit me in the wallet department also.  They have now been ironed out, hopefully you will find a solution to your problem also?

Take care for now and happy riding buddy 

[Tintop]

Thanks Honda Brat.  I'm not to concerned, a set back, but certainly solveable.

Got out the magnifying glass, and had a close look at the part that failed.  It looks like the part (brass) stretched through the cross hole area (slightly concave) when the bolt was tightened.  This would have caused mirco fractures on the inside (weakest point).  The heat, vibration, and oil pressure then caused the part to fail.  They are fracture lines, not tears.  As I said before, luckily it when when it was stopped, or it would have been a serious crash from an oil soaked rear end.

A helicoil ( syscrush), and a gun & cross drilled flange bolt may be the answer.  Sizing will be the issue, to maintain sufficient internal clearence for oil flow.   Off to look at bolts.

[Terry in Australia]

I'll have to wait until I get home to check out the pics Brian, (my defence department firewall won't allow pic hosting sites) but anyway, that's a shame mate.

Your kit was the "prototype", and I've since come up with a much better centre bolt design, so if you'd like to mail me back the adapter plate, I'll modify it to fit the new bolt and get it straight back to you. Cheers, Terry. 

[Tintop]

G'Day Terry, thanks for the offer.  I'll check out shipping costs, but unfortunately, time is now the issue. 

The bike was suppose to go to Mosport for the vintage bike festival next weekend.  I can solder the broken part together as a non running fix, so the bike can be displayed, but riding it would be preferred.   Do you have photos of the revised setup?  Given the costs of 'quick ship' to OZ & back, it may be less expensive to just have the machine work done here.  I'll check out shipping today.

My biggest concern is that the 'prototype' doesn't have the 'meat' between the 'Out' gallery, and the 'In' to allow for any material to be removed.  Currently the threaded end of the brass mount is slightly larger than the 'In' return gallery.  I'll pick up my caliper and take some measurements today.

Cheers,
Brian

[Tintop]

It was a good thing it rained of and on all day today, let me get on with finding a fix, and not wish I was out riding.

I did figure out how to use an M15 x 40 (1.0 thread) bolt.  Question is if such a thing is readily available.  If not, the option is to turn down an 18mm bolt.  Sending everything back to Terry to be upgraded to Mk2 specs, will mean the bike is out of commission for a minimum of 3 weeks.  I could use this time to do the cam upgrade; and then recheck timing & carbs, once the adapter is back.  It's also likely going to take 2 weeks to get things done here (and cost more ).  Best thing would be to find somebody close by, who could do the work right now.  If not, it looks like the bike is parked, and will miss Mosport in 6 days.    Will make some calls tomorrow, and see.

[Swoop]

FWIW..................I have some M16 x 40 soc cap head bolts (takes allen key)
Steve

[Tintop]

Thanks for the offer Steve.  I may pop over and check one out against the insert for the engine, will call you.  However, when I was doing comparisons yesterday, I felt M16 might not leave enough meat in the insert.  Hence looking for an M15, having one made.  I can get a Ti one (used for cranks), but it is too short.

The option of sending it back to Terry is still on the table, and I will make a decision on that tomorrow.  My hesitation has nothing to do with Terry, or his skill(s), but rather the fear of it getting lost in transit.

[Tintop]

So the Mk1 adapter plate is on its way back to Terry.  Consensus is the original design needs to be beefed up, as was done for the Mk2 version.  Terry is going to try modifying the Mk1 to Mk2 specs.  If the isn't possible then he is going to make a new Mk2 adapter plate. 

Means the bike is now parked for a minimum of 2 1/2 to 3 weeks.    If I get it back by the 1st weekend in September, that will give me 2 weeks to sort out any bugs, before MCRider's Indiana ride on the 17th.

Time to start polishing the 400 for Mosport, and checking every nut / bolt / adjustment on the 550 in preparation for the 17th.

[Terry in Australia]

Don't worry Brian, I'm standing by my letter box and as soon as the postman pulls it out of his sack, I'll run down to my shop and "MK2" it for you. Now stop stalling and install that cam! Cheers, Terry.

[Tintop]

Quick update.  Terry has rec'd the adapter plate, and is in the process of modifying it to Mk2 spec's.  I also decided that with the bike idle, I would go ahead and install the Mega Cycle cam.  So yesterday I removed the rocker box, installed the new rockers, and sent it over to have the cam degree'd.  Won't know how everything works until the adapter gets back, and I can start it up & road test.

Do have some concern with the current jetting, after looking at the plugs.  There is definitely something wrong with number 2 carb, as it is showing rich (almost fouled),  all the rest are a very light tan.  Will have to pull the float bowl and check the main & emulsion.  Hopefully it is not the new slow jet, as this is a push in, and requires the carbs to be pulled.

[Raef]

It could be as simple as a sticky float or the float Valve not seating, all it take is one grain of sand.

How many hours or miles has this bike traveled under it's own power, btw hoping to see it in Indiana in a couple weeks

Mark

[Tintop]

I'm doubtful it's as simple as a sticking float or valve, as there is no sign of overflowing.  The bike had just done an extended high rpm run, and idled for less than 30 seconds.  As the slow jets had just been changed, I suspect dirt in a jet or emulsion tube.

As for road time - not much.   That's why the push to get some on it before the 17th.  If the weather looks like it will cooperate I'll be there.