Engine Rebuild Parts

[CB1_Boost]

Greetings mates.

After many months and speculation it looks like I'll need to rebuild some of my -1 engine.

From what I've learned, I'll be needing:
Head gasket
Base gasket
Valves (hopefully not 8 )
Pistons
Rings

And all the bits and pieces in between. 

Anyone know where to find these parts (aftermarket or OEM) that aren't marked up so high?
Anything else I should know/replace while the motor is taken apart?

Thanks.

[clarkdw]

A quick check of suppliers indicates that you will likely have supreme difficulty finding pistons at all. You might want to get in touch with Wiesco and see if they have any leftover pistons. I would for sure replace crank and rod bearings if you have the engine down that far. If the barrels aren't worn real bad you could just hone them and fit oversize rings. That would keep the cost down significantly. If wear is bad the pistons could be knurled and use oversize rings. Not ideal but if pistons are NLA it is a choice.

Make sure you get new circlips for the wristpins. Do not reuse the old ones. An important lesson learned on the small Honda utility engines I built for racing Go Karts. Also replace the valve seals even if not the valves.

Honda parts not quite so expensive: http://www.hondaparts-direct.com/default.asp

[a_morti]

I've used this breaker before, he isn't far from me (near my old office, now about 25 miles from my home) and is a decent guy.

http://cgi.ebay.co.uk/Honda-CBR400-NC23-pistons-rods-set-0200-/350345000815?pt=UK_Motorcycle_Parts&hash=item519230776f

[Drewski]

It might be worth checking David Silvers. I've seen them sell new parts like cams, clutch basket etc and once seen a new cylinder block sell for a fraction of the listed price.

[CB1_Boost]

Thanks for the replies.  I'll look into the sites. 

Just found out 3 cylinders have exhaust valve leaks.  It'll be torn apart this afternoon so I'll have a better idea of what parts are needed. 

I'll keep this updated.   

[91cb-1]

If you need parts and don't mind using second hand parts i stripped down an engine with only 30,000 kms on her last year. have pistons cylenders etc.

[JX]

it might be worth your while just trying to get a complete replacement engine from a breakers somewhere.

there is one here,they ship worldwide:
http://cgi.ebay.com/HONDA-CB-1-CB1-ENGINE-PROJECT-/120649941679?pt=UK_Motorcycle_Parts&hash=item1c174c02af

just a thought anyway.

here is another one:
http://cgi.ebay.com/HONDA-CB-1-1994-Engine-/390261026658?pt=UK_Motorcycle_Parts&hash=item5add5eaf62

strangely enough,the CB was officially sold in the States,yet all the engines are in the UK

[CB1_Boost]

So after the mechanic opened up the head/block....here's a list of parts I need for the 3 bad cylinders:

Exhaust valves           (6)
Exhaust valve guides   (6)
Valve Seals                (6)
Head Gasket               (1)
Base Gasket                (1)
Rings                         (3 sets)

Total cost is going to be at least $300 USD in parts
Another $250 for labor and about $200 for the machine shop.

Total of about $730 just to get it running again.

Not sure if it's worth the price on such an old bike.  But gas prices are on the rise and it's a fun bike to ride without a doubt.

Thoughts / suggestions ?  

[91cb-1]

Find a second engine with less milage on it on e-bay and just replace, for about you gac then replace any crank cases, sumps etc that may be damaged with those from your own engine, a second hand engine will be a LOT cheaper
of course you could always use this oppertunity to put a hurricane 600 engine into it, give it a bit more umph! 

[clarkdw]

Given that there are almost never engines available in North America in one piece on ebay, the cost of shipping one from the U.K. or Europe would most likely be as much or more than your rebuild my vote would be to get on with the rebuilding. Finding some (valve guides) parts may be difficult.

I would strongly suggest to do all four sets of rings. You will have the barrel off anyway so why not do all. Doing three is a recipe for tears later. I hope that the head will receive a valve grind on all the valves and just replacement of the burnt ones? Again anything less is very false economy.

If you decide not to do the rebuild and part out the bike you will get very little back. Look at all the CB-1 parts that have been on ebay from parts bikes for long, long periods of time. The few parts that really sell quickly will not make it worthwhile. A running bike will certainly get most if not all of your rebuild costs back.

At a estimated realistic cost of $1000 I would not hesitate to do the rebuild and continue to enjoy the bike.

[mirror man]

i've got a motor sitting in my garage.dont know if its any good to you, it had sub 30000kms on it.was working un till it stopped...... so bought another and fitted yours for shipping only( i.e free,grataus) or to any one. to be honost i dont know if it will start,like i said its free

[CB1_Boost]

Clark - Appreciate your input.  I'll have to agree with you on continuing the rebuild.  Are you saying I should replace the 4th set of intake valves as well?  Only 3 cylinders have leaking valves.  And I did find Valve Guides for $12 a piece....just not sure if they're in stock or not.  I'll ask the mechanic about replacing the 4th set of rings.  Can you elaborate on the valve grind?  You mean what the machine shop will do to cut them and fit the valves in correctly?

You're definitely right about the parts on ebay.  I'd like to ride the bike some more before moving on to something better.  Thanks again.

Mirror - Thanks for the offer, but probably more logical to rebuild the motor.  

Anything else I should replace / check while it's all torn apart?   

[clarkdw]

For sure replace all 4 sets of rings. Taking the cylinders off the pistons and refitting it without putting new rings on all is very likely to mess up the sealing on the fourth cylinder.

As far as the valves. You are replacing 6 exhaust valves and having those valve seats recut. (The seats must be recut to be concentric and seal properly when fitting new valves and especially new guides) As long as the head is disassembled you should have all the seats, both intake and exhaust, recut for good sealing at the same time. The old valves can be ground and then lapped in to the newly cut seats unless they are really burnt. The 6 exhaust valves probably are burnt beyond repair.

All the valves, both intake and exhaust, should get new seals.

After grinding the valves and cutting the seats the machine shop will probably need to shorten the valves or you may have trouble getting the valve clearance correct. If they are familiar with motorcycles they should have no trouble knowing how much to shorten them. Your mechanic will have to recheck all the valve clearances when assembling the head as they will all have changed with the grinding and seat cutting.

I will try and think of any other suggestions in the next day or so. Keep us up to date

Too bad you are so far away. I would give you a hand and you could do the job yourself. It really is a fairly simple project if you are given a little help and guidance and I have all the cutters to do the valve seats at home from kart racing engine builds.

[Daveontheedge]

What about some oversized rings and boring it out a bit?

[clarkdw]

Oversize rings will only allow a deglazing (honing) of the cylinders. The rings can then be filed to fit the cylinder with the correct end gap. Actually boring oversize would require oversize pistons which are no longer available.