New member with a serious engine issue

[Phil H]

Hello all , first post on the site so go easy on me
I have a 1981 pro-link that i have been customising for the past couple of years . After nearly finishing the bike and road testing it , all had gone well until on the motorway the cam chain snapped ! I have the bike booked in next week to see what damage is done . What i'm thinking is i may now go for a big bore kit as the engine will be out . Would anybody recommend a kit ? I have already fitted Cr round slide carbs from Tims USA , dynamite coils and a custom free flowing exhaust .
The bike will only be used on the road and being reliable is a big must for me . I'm not looking for big power just a nice fat midrange and little more poke than standard .
Any input would be appreciated .
I'm based in the U.K
Thanks
Phil

[daves79x]

The only situation I've heard of where a camchain broke is the dreaded 20-mile rebuild. The cams were installed incorrectly, I'll bet. Be sure that if the same guy looks at it that built it the first time, be there to document cam positioning. If it's wrong, he owes you. And if he was not the one, go back after whoever did build it. You will find some very expensive head damage. Most valves will be bent and most guides will be cracked. I'd have all the rods checked VERY closely for any bent ones also. Sorry, but this will get expensive if you are having someone do all the work.

Dave

[Russ]

Hi Phil, and welcome along.
Before you find out what damage there is you need to find out why it happened. Best not to tear into it and be methodical, if someone else did any work on the motor I wouldn't be taking it back there for the inspection. As Dave said above, it's very hard to snap a chain so it may be one pair of cams are 180' out. It will be an expensive repair.
Let us know how it goes, plenty of help on here if you need it.
Russ

[jnnngs]

Phil,

Where abouts are you in the UK? I am in the Basingstoke area so may not be too far from you, happy to help out if I can.

Paul.

[Phil H]

Hi all and thanks for your reply's . I should of pointed out that during the building of the bike we only put new shim's in . We didn't do any other work inside the engine .
Sorry for not explaining this in the original post .
Unfortunately i'm useless at mechanicing so will be having the work carried out for me . Looks like i need to cancel xmas as i know this will be expensive !!
If anyone could point me in the right direction for parts that would be great , i've only used David Silver before .
I did manage to ride the bike for approximately 600 miles before the chain snapped , this was the first time riding the bike for me . I loved it and was only thinking how sweet it was to ride before the chain went . Just want to get it fixed and back on the road as it took 2 years to get to this stage .
Paul thanks for your offer of help i'm in SW London , the bike is booked in with a guy called Steve at Rother Classic's in Yorkshire . Dropping it off next Wednesday .
Will post more when we know what the full damage report is and again thanks too all .
Phil

[wyly]

best CBX spares supplier in europe that I know of is Bert http://www.sixcenter.nl/index.html
only Louis at would have more... https://www.usedcbxparts.com/

I recall a zero miles CBX back in 1978 snapping a cam chain right in the dealers showroom... I was there when it happened

it's gonna be very expensive, I know all to well it may be less costly to buy a running engine from Bert at Six Center he had a number of engines when I was last there.

[Phil H]

Hi Wyly , thanks for the recommendation . I have contacted both Bert & Louis and they have engines , just waiting on prices .

[wyly]

I would guess Bert is your best bet, shipping would most certainly be less expensive or you could even drive there and pick it up if you have the appropriate vehicle...and Bert will give you a tour of his facility.

I have a Wiseco big bore kit, estimated 8% increase in power, very reliable set up for everyday commuting

[herdygerdy]

OUch that hurts! Been there done that back in the early nineties when I had, ahem, "far more ambition than skill".

Putting the cams in wrong (twice!) I broke two cam chains and bent 9 valves, both within about 5 kms.

Why does it do this? If the cams are in wrong, the cam chains are trying to open DOUBLE the amount of valves at any given point (four instead of two), with two cylinders on the compression stroke at the same time. Turns our silky smooth six into a horrible sounding and feeling 'twipple', if you get what I mean.

FYI, Captain in New Zealand on the 1100F.net site sells the CORRECT and ENDLESS (no joining link) Morse cam chains for the CBXs. Most of the ones sold by Honda now are not the same as the OEM ones fitted way back when and have the incorrect tooth profile, being forced to sit higher on the cam sprocket tooth. PM me for his contact details, you'll be pleased you did.

For reasons why yours broke, perhaps a joining link had been incorrectly fitted, or the wrong chain entirely or (less likely, given you said you rode it 600 kms) the cams were fitted with one cam installed 180 degrees out.

Good luck on this $$$ journey. At best, you will have bent some valves.

[Phil H]

Quick update on this . I have gone down the route of rebuilding the engine rather than buying one . I will give some updates next week of the total damage we have found .
So far it's not looking too bad could of been much worse .
One thing i do need to get hold of is the cam chain tensioner ( the small one ) if anyone could help with this that would be superb !
Thank you for all the good luck messages guys .
Thanks
Phil

[Larry Zimmer]

Can always give a shout to Louis at usedcbxparts@hotmail.com