If it ain't broke, don't fix it by Orvo Valila

At my desk there is a piston. Nothing out of the ordinary really. Many a gearhead has got a piston on the desk. It can be an ashtray, it could be a nice polished shiny paperweight or just a memento of something worth remembering.

Mine reminds me of how things that you take for granted for years can all of the sudden jump up and bite you in the arse.

What is that supposed to mean then? See, a couple of years back I was on a leisurely ride with my kid bro (he rides a 350cc BSA so I was able to keep up) and about half way I started hearing this weird jingling kind of noise out of the left cylinder.  This started to concern me in the beginning but since it was getting no worse and CJ engines are really not world famous of their quietness, I decided to go on until I get there or something happens.

Nothing happened. I got where I was going and thought to take a look on that following week. So, after a couple of days I started tinkering and removed the head of the left jug. Nothing out of the ordinary except the usual amount of carbon soot and oil residues. I took a look on the head. Nothing. Valves good, no marks in the chamber, nothing.

After a brief doubt on my mental sanity I decided to shake the head (don’t ask me why). Jingle jingle.

Aha! A closer peek into the intake and more shakes. What the? About half in piece of the valve guide was loose on the valve and riding up and down. Well I’ll be buggered?

Lucky for me I knew that a buddy of mine was coming in from Beijing to Helsinki (yeah I was in Finland at that time) so I did not even bother taking the head apart. Quick e-mail and a couple of phone calls saw to that I was getting a pair of brand spanking new CJ OHV heads following week. Quick bolt-on installation and I was back on the road in no time, happy as a pig in…erm…mud.

This incident was total bygones in my mind for years. Out of the sight, out of the mind. Until this summer that is, when I got to my little ritual of starting the vacation. Y’know….. drag the bike out of the shed, add the oils, wash the dust, check this, check that. The bike started all right in a very satisfactory manner, but I thought I heard a jingling kinda sound on the right side this time. Made some test runs, let the engine warm up, triple-check the oil level. Nope. It still sounded weird? Oh well, it must be the stupid valve guide again then. So I removed the head with considerably more effort this time as it was the right head and it would not have the space to come off unless the bike is tilted away from the bucket first.

Nevertheless off comes the head but no matter how much I shake, no jingle? Odd?  Well, I had the jug apart and had still the spare right head from that shipment years back. Logical solution to my simple engineering mind was of course to slap the new head on and be on my merry way.

Which I did and sure enough as soon as the bike ran again the jingle was gone. Well pleased with myself I packed everything away, did final bits and pieces and was on my merry way indeed.

So what has this got to do with the piston with a gaping hole in the dome and valve jammed into it? Where are all the flying parts and exploding engines ( imagine a sound effect here….) ?

The whole sad story started unraveling little by little a couple weeks afterwards on the way to….you guessed it….Ural Roikka Rally 2005. This year the rally was a tad further away from us, plus very conveniently my buddy Tapsa’s summer location was on the way. So we decided to do the trip in two legs this time round and left a previous day already. First leg to Metsämaa was rather incident free, the usual adding oil and getting lost nonwithstanding.  Almost there we decided to stop for a bite and just at the gas station the bike all of the sudden started running rough, missing on the right side? Remembering that I’d had some problems previously on the right side running lean, I took off the plug and sure enough the electrodes were beaten and insulation badly cracked. Without any further thought on it I replaced the plug and made a mental note of buying more spare plugs of the colder kind. Bike started running just fine and after the break we went on, me admiring what a clever mechanic I’d become over the years.

Stopover at Metsämaa was very nice indeed, including the usual sauna, cigars, bike stories and a very fitting two-stroke Margarita mixer that was thoroughly tested and found very suitable for a gathering of this nature. Yes, you read right. It was a Margarita mixer with a 25cc or so two-stroke engine with handlebars, mirrors and a windshield. If there is a cooler biker gadget in the world I do not know what it is

So anyhow…  As the rally site was not too far off anymore and it was a very nice day, we decided to take a scenic route adding some 100km to just for the hell of it.  With hindsight this was a fabulous idea as it turned out.  Luckily we stopped to get some gas and I got myself a pack of spare plugs. The cooler kind remember? Luckily,  because after a few miles the bike lost the right jug again. And the plug looked like it had the living crap beaten out of it. OK a new plug was obviously in order. But bearing in mind that I was still almost overwhelmed by my excellence in bike repairing I was absolutely sure I knew where the problem was. Ahhhh…. The lean carburetor…but of course!

Off to the next gas station (bike running like Swiss watch… well almost) and replace the carb on the right hand side. See, I have all kinds of spares with me because I am such a clever bike mechanic now. All my spare parts actually, except those old heads that were replaced. Who’d need a complete head anyway on the road? So in with the new carb, test run, cup of coffee and on the road again.
Running like an angel until a few miles down the road again… right one dead again. This time with lots of backfire banging and flames.  Open plug, electrodes almost touching each other. Now it finally starts to dawn on Mr. Bike Mechanic Extraordinaire that this might be something more than just a lean mixture problem.  But rain clouds are following us and we’re just so darn close. So new plug in again.
A few miles and again…..
And a few (maybe a dozen this time) and again…..

And again. See a pattern developing here?  By this time the few alert brain cells left in the thick head of Mr. Bike Mechanic are trying to tell him that there just must be something loose on the piston to kill all those plugs. So we try again this time with a few extra spacers under the plug.

Maybe it would help to lift the electrodes a bit further away from the chamber or get them into a different angle… whatever works mate.

And it seems to work… for a while… until the same banging and backfiring happens again. Plug electrodes just touching each other. This time the plug is not too bad looking so I decide just to open the gap a bit and try again… until...
…again…

By now the fellow riders are already coming up with helpful suggestions like “ditch it“ or “we can give your wife and beer a ride and go ahead”. What would you do without  great pals like that?

Out with the plug, open gap, in with the plug… few miles again and…

Now by this time I’m getting pretty good at that and every stop takes less than a minute….
After a while we came across to a gas station again and it was painfully obvious that something had to be done rain or no rain. 

Interesting thing about biking is that when your bike breaks down in the middle of nowhere and you’d desperately need a spare part or a tool, you can bet there is absolutely nobody around for the next three hours or so. However if you’re reasonably well prepped, got the tools and would not really care for any extra audience, you can guarantee a convoy of fellow bikers will stop by. And the inevitable questions are: “is it broke?“ , “are you fixing it?“ and “how did that happen?”.  I figured that must be because bikers are such a sociable breed. ;-)

So after some hectic disassembly the head is off again and et voilá.  There were indeed some mysterious  bits on the piston (which was NOT looking good by the way ).
Some of them fell off from on the intake valve. Also some weird aluminum chaff in the valve cover??

Great.  So now we knew for sure that the damn thing is falling apart. And once again, just like the first head sometime back, you just cannot see the lower end of the intake valve guide anywhere. Mr. Bike Mechanic Man makes a lightning quick diagnosis that the valve guide must have broken in half also on this head and the loose bit shaking up and down on valve shaft has just disintegrated. Smaller pieces have been ingested to the engine and gone through after been bouncing back and forth for a few thousand times, scarring the piston, head, cylinder (bear in mind that these are bits of steel) and at suitable moment knocking the plug dead before exiting via the exhaust valve.

In the meanwhile the bigger pieces had been left on the intake valve waiting for their turn after being ground smaller…

Great theory ain’t it? Although somewhere in the back of my head the voice of reason (?) is trying in vain to tell me that there should really be more and bigger bits of those left on the piston if that really were the case…

Aaaanyhow… the rain is upon us and we make probably an new West Finland record in assembling the head and reconnecting the bike to the bucket. Problem solved, right? On the road again.

Yeah right… Same issue after a few miles. Banging, flaming, backfiring, the works. Without even checking the plug I know by now that the electrodes are touching again and the plug is next to useless.

The trip that we were estimating to take bit more than an hour had now  taken more than four hours. We’re all more than a bit pissed off (for various reasons), it was pissing down and we were just a few miles away. I made a decision to keep pushing the bike as long as it would run.

So on we went, 40mph. Putt-putt-putt-BANG-putt-putt-POW-putt-putt-KaBLAMMO! We must have scattered all the wildlife off for the radius of 20 miles with that infernal racket.

By the time we get there and park the bikes I’m ready to GIVE the bike away to the first featherbrained dimwit that is stupid enough to ask. Lucky for the bike all featherbrained dimwits stayed elsewhere or were scared away by my grim appearance.

As it kept drizzling down in a manner that only a beautiful Finnish summer can provide, we decided to concentrate on more appealing pastimes for the time being such as alcoholic beverages, sauna, kicking tires and general BS. Much better option than even trying any repairings that night given my state of mind at that time.

The night went on and little by little my mood got better as the old gang indeed was together again, sauna was hot and beer cold… It’s never exactly quiet there but it seems that this year the lads were compensating the pissy weather with extra merriment some of you have already seen, e.g. the burnout vids on Dan’s news. Among other things.

The next morning was looking a tad better and after some breakfast and coffee, so did we. The rain had stopped at some stage during the night so I thought to bite the bullet and open the head again for a more thorough investigation. Now, as I mentioned, a fast patchwork repair on the roadside is a crowdgatherer… Imagine what that would be like in biker camping grounds. Not that I could blame anyone for seeking some extra program. I’ve been guilty for the same sin myself many a Saturday morning in Roikka meetings. There is always some poor soul trying to piece something broken together and there is just something mystic about how that scene draws fellow bikers with endless advises and stories in. Y’know, “My uncle had a '53 Jawa once and it quit on him in the middle of nowhere and he had to use a potato as a capacitor... and this was at fall time and he was going to races and he had a…”

You get the picture…..
Interestingly enough there was still no obvious reason for the weird plug gap closing as there were still no major bits or pieces on the piston, and most of the small bits that were earlier diagnosed for pieces of the valve guide were on the intake valve again?

However when I got to disassembling the valves and the springs from the head the whole horrible truth started dawning on me.


Up until that point I had had the faint hope that it would have been just a matter of replacing the valve guide and be done with it. NO such luck Jose. Alas, it turned out that before the valve guide had disintegrated into gazillion pieces, it seemed as if the C-clip that prevents the guide to sink in the head had broken and the guide had started moving on the valve little by little on its fittings.

The head is, as we all know, made of aluminum and the guide is essentially a steel tube. It does not take all that much for the valve guide to grind itself VERY loose in the fitting and this sucker had about good 3-4 mm on both sides. So here’s the mystery. Every time the valve opened, there was not anymore support from the loose valve guide and the end of the valve was moving sideways every which way for that 4mm or so. There is not all that much space within the head so repeat that valve opening process a few thousands of times and it will touch the plug gap just enough to close it.

Sure enough I was excited enough of my wonderful discovery to have forgotten to take any photos of the actual heads. You can see some bits and pieces left of the valve guide here nevertheless. The exhaust valve guide seemed intact thank goodness.

So now I knew what the problem was but not really how would I have fixed it or at least get the bike patched together long enough to get back home the next day?

Bear in mind that only a few days earlier I had used my spare head on this side of the engine and never saw a reason to pack the old one as spare with me when starting on the road. Yes, I was kicking myself.

Well, we were in a biker meet and there was a swap market. So I grabbed the spare valves that I had and went ahead for a hunt for a really oversized valve guide or two. After some hectic digging in the swap shops and vendors warehouse vans in the place it was painfully obvious that I was not going to find anything that would fit both the valve and the mutilated head. Loads of other very weird and wonderful Ural, K and Dnepr parts and even some Chinese bits but not really what I was looking for.

There were some Ural OHV valve guides however and although they’re about the same outer diameter as CJ guides, they have a nice shoulder that keeps them in place in stead of the C-clip the Chinese heads are using. A cunning but desperate plan started to formulate in my mind. If I’d take a Ural guide and use it on the exhaust side, I could use the exhaust valve guide on the intake side, use some thick sheet aluminum wrapped around it and force it into it’s place. The C-clip should be wide enough to keep the whole thing in the right height and stop it to sink any deeper than necessary.

Quick guesstimate judged the aluminum head gasket of Dnepr 750 flathead about the right materiel for filling the extra clearance between the guide and the head. Good stuff, soft enough to be cut with a Leatherman.

Only minor problem there was that Ural valve guide was about 12mm too tall to fit. Now I know cutting the guide on a spare tire with a hack saw does not exactly qualify as precision mechanics but beggars cannot be choosers as they say. 15 minutes of furious hack sawing and some elbow grease sorted that matter nevertheless. Thanks, Tapsa.

For the centering of the valve we just had to pray that the old one had worked itself loose evenly on all sides and was not skewed in any direction. Cold fitting seemed good anyway so I worked the valve guides in the place with a gentle touch of a hammer and seated the valves with some grinding paste even.
Before slapping the whole thing back on the jug I took a good hard look on the piston to figure out whether or not it needed replacing as well. The cylinder was not likely to have a long life by the looks of the all scarring at the top end caused by all that steel flying around, so I decided it was not worth it to put a new piston into that busted jug.
Head on, bucket hooked back up… the usual drill. Even the pit crew was getting the practice now so it did not take too long.
Before too long it was the moment of truth. Will it run? If so how long? Will the filling hold? Is the centering…well….centered?

Only one way to find out.  Check oil levels, check gas, Ignition on and… IT’S ALIVE!!!


The feeling of relief was incredible. OK given the bike was still not running like a Swiss watch but then again it never was. The usual klings and klangs were still there all right. Somehow in my paranoid mind it sounded like there would have been some additional noises. Most important thing was anyhow that it was running. Even in time for the convoy. And the convoy was to be the trial run as we were heading to Uusikaupunki that was not too far of should the worse come to worst.

As seen from the previous photos sent to Dan we made it to the convoy and back. As usual the convoy of Russian, Ukranian and Chinese machinery got the attention they rightly deserve. My bike was running reasonably well and a little hope started to dawn that maybe, just maybe we’d be able to make it after all.

So Saturday evening went in the usual manner pretty much like Friday… good company, good friends and good bikes. Without forgetting good beer of course. ;-)

So Sunday morning came again and we started getting ready to start heading home. Not too early though as there were some minor repairings still to be done on a couple of bikes plus the riders needed some breakfast and recovery as well.

The trip back was following pretty much the same route as on the way in with a brief stop at Metsämaa at Tapsa but once again the rain was looming so we had to make the stopover rather brief and then hit the road again.

Apparently the trip had been too easy this far as a few kilometers before Metsämaa I started paying attention to the volt meter. Now I know the el cheapo meter that I have on the bike is not really the most accurate one, but the wobbling needle seemed to drop lower than my comfort level. Occasionally the voltage went under 10VDC, other times it seemed to stay more or less 12V.

Nevertheless there was another problem developing there. One nice thing about these bikes is however that the battery is ample sized (and there is probably a reason for that) and you can ride surprisingly long distance on a battery only. Of course that would mean that you can ride without the headlight on. However when it rains it may not be all that a great idea to ride without lights on. That’s right… a few dozen kilometers off the break the rain finally caught us. And not any drizzle either. For the next hour and a half we were riding in a torrential downpour.

Now that posed a different problem altogether. I was not really too keen on riding in that kind of weather but if the battery was dying indeed, there would be little point to stop and wait for the rain to go by (it was not looking like that anyway) especially knowing that at some stage when you’d stop the bike it would not start again.

So on we went and got more and more wet by the mile. Side observation, Chinese Gore-Tex is not really waterproof after awhile. We had layered that “North Face” jacket, layer of plastic film, leather gear and the usual undergarments. You guessed it—still all soaking wet. After a while there was just no point stopping anyway as we were well and thoroughly soaked no matter what.

I’m not going to bore anyone on the “Chinese water torture” details as I’m sure each and every one of us have been there done that. I would not even be able to tell the scenic details of Finnish backwoods as all my focus was on the white line on the side of the road (pretty much the only thing I was able to see anyway) and the wonderful co-motorists on the road who seemed to have little sympathy for the poor couple struggling their way through the Finnish version of monsoon.

Somewhere close to Jämsä (which means a lot to all I’m sure) the deluge was starting to let go a little and we were able to breathe through bandannas without having a drink at the same time. Voltage on the battery was not showing any better but the bike was running nevertheless and we were slowly but surely approaching the destination of this via dolorosa when…

...all of a sudden there was this horrible Ka-Runch sound followed by a few seconds of  klickety-klack-bang and the right cylinder just died again. This time it sounded SO bad that I started having really bad feeling about my jury rigged valve guide contraption. The bike was still running on one cylinder so I pulled it on the roadside on crossroads. The suspect was obvious so after stripping a couple layers of soaked gear I started taking the right jug apart with the all the drill and practice gained on this wonderful trip. As I had the bike tilted away from the bucket and the head off; I went to put the head away into the trunk of the sidecar without even looking at it as the head was kinda hot and I was in a hurry to put it down. My dear wife with the ever ready camera headed to the culprit to snap a couple of action pics and I heard a very innocent question: “Hon, is it really supposed to look like this?“

Oh great now what, I thought and leaned back to peek into the jug and…
...somehow it started to look like this was finally the end of the road.

Ooookey. Time to admit the defeat and call in the cavalry. Earlier we’d spoken with my brother that he’d spend the weekend at Western Finland as well and would have been heading back the same road sometimes Sunday afternoon… so I grabbed my cell and rang him.

“Yo, dude…’sup?? Yeah, great, just fine.... well… not really…”
“Say…. you wouldn’t happen to head this way anytime soon would ya? And…er… I do not suppose you would have a trailer on tow now wouldya? No?? Yeah…kinda figured you would not hitch that round just for the hell of it….”

OK so it was not that bad after all… we were about 90km off from our destination so we agreed that he’d pick us up and we’d go off and get back for the bike later that night. The bad news was that he was still a couple of hours away… and we were still kinda damp even after a change of some clothes on the roadside.

Nothing to do but wait. Oh well… back to the bucket for the supplies.

This was going to take a while. “Have I ever told you this one time in Taibei  when we went to… I have already? Really...”

After a couple of damp hours the cavalry did arrive indeed in a black 605 Turbo and we loaded all the gear in and went to get the trailer. 
After an hour and a half we were back again to load the bike.

When finally we were getting the bike back to the garage it was getting kinda late already and we almost literally collapsed in bed totally exhausted.

This whole ordeal was bugging me enough that next morning I just was not able to leave the bike alone but I had to get it back together right away…

It wasn’t pretty but certainly repairable still.
The only piece I was missing was new cylinder, everything else I pretty much had. Even the head that I had replaced only a few days earlier that turned out to be just fine. So it was going to get together with the old jug and I’d worry about a new one later.
Looking at the mangled pieces of aluminium found in the crankcase it was obvious however that sooner or later I would just have to take the whole engine apart for a rebuild. This is something that is planned for next year vacation as soon as I have the parts arranged from China. Thank goodness we still have some buddies still living in BJ.

The bike is back together now (even broken once more already but that is another story altogether) running and all. Alternator problem was just another burned stator that I replaced with a spare. I would definitely not take it on any longer trip without opening the whole engine, but running anyway. 

So what have we learned from this whole sad story? Sure, if it ain’t broke don’t fix it, but seriously, check your spares before bolting them on. Assembling an OHV head is not exactly rocket science but seems like the quality of the spares sometimes leaves something to be desired. If the material quality and the tolerances simply are not quite there the results may be as described above.

Contributing factors to the disaster here probably have been badly installed guides, incorrect forging of the valve guides, too tight tolerance between the valve and the guide and overall warped valves (?!?!)

All the talk in CJU and other arenas about quality of counterfeit parts seems to hold more than a little truth there.

One thing for sure, before I am to slap a head on any engine now I will be sure to take it apart first and take a bit closer look on it.

That’s it Brother and Sister CJ bikers. Hope you have learned something about my miseries or at least you consider yourselves warned. ;-)

Oh yeah, the hog. The hog you saw earlier is nobody less than the President of MC Hehku himself.

MC Hehku was taking care of the excellent arrangements of this year’s Ural Roikka Rally and for most of the weekend The President was honouring us with his presence. Please pay attention to the correct attire.

Mr. President was very sociable like a well behaved biker should be and personally I would not believe a word of those rumours that he gets cranky after a few beers too many.