Post Valve Check/Shim, Running Lean

[cobbadiggabuddyblooo]

Glad you found the issue...
Looks like the inlet cam has unloaded from the timing marks because when in place it has load upon it from slight compression on the inlet valves on cylinder no2.
If you don't get the front chain runner and tensioner in place while holding your tongue in the right place in your mouth the inlet cam can easily unload and slip on the chain.
I totally agree on being in the right frame of mind when placing the cams back in place.
Once you have pulled things apart and measured your clearances, take a break.
Round 2 is removing the cams , replacing any shims that need addressing, making sure all is aligned and rechecking clearances.
Then the same challenge of jostling the cam chain and stopping the inlet cam from unloading as it has some valve spring weight against it.
Glad you stuck with it and sorted the problem yourself.

It's always good to get things apart measure your clearances and right them down.
I give the lads a sheet with an outline of the head with the valves numbered.
Under this is a excel style section where they jot the clearance on the numbered valve, the shim value fitted, next is the replacement shim value and new clearance values.
This makes it so much easier next time you do the job because you know the values and any changes from previous service.

Couple of drops of yambond on the cam cover gasket to stick it in place in the cam cover is another handy tip. You'll usually find that rubber gasket can be reused a number of times, but it's worth spending a couple of $$ and just replacing that o ring on the water pipe.
Should be plain sailing from here for you..

Just a note, when ever I have had someone else do any sort of work on my bike when replacement parts are used, I always make sure they give me the old parts removed or replaced ...

I usually find the cam chain adjuster will give you 9 clicks from from all the way in to good weight against a new cam chain.

[dandywarhol]

What an incompetent prick. It had all the hallmarks of a mistimed engine. Do you even think the chain was replaced? He would needed to have removed the engine side cover to access the oil pumps/balancer shafts - any signs of gasket smeg there Neil?

[Overlord Neil]

Yeah not good, atleast I have a back-up bike or I would have been really pissed.

I'm pretty sure its a new cam chain, the guy showed me the old one, when it was still in the bike, to recommend the change. You could move all the links on the pins so it was pretty worn. The guy is an ex-courier mechanic and has an Aladdin's cave of a workshop, so he connected one of the new cam chain to the old one and pulled it through, rather then strip the engine to fit it 'properly', he seemed to know what he was doing and could see ££ signs spinning so I agreed to it. Having seen how shoddy the rest of his work is I might strip the engine completely and start again.

Cobba the gasket thing, I get most of them can be reused, but not when only half of it is stuck to the sealing face and the other half got shredded away during separation. Its just shoddy, I gave the guy the bike for a whole week and told him to advise me of anything that needed replacing, like the inlet rubbers. But he left it till the last day then rushed it when I pressured him to get the bike back because I needed to use it the following day.

With the benefit of hindsight [that cruel mistress] I'd have taken the bike off the road to work on it at my leisure, strip it down, work out the shims I needed (if any) order them in and slowly put it all back together again.

[cobbadiggabuddyblooo]

Yeah not good, atleast I have a back-up bike or I would have been really pissed.

I'm pretty sure its a new cam chain, the guy showed me the old one, when it was still in the bike, to recommend the change. You could move all the links on the pins so it was pretty worn. The guy is an ex-courier mechanic and has an Aladdin's cave of a workshop, so he connected one of the new cam chain to the old one and pulled it through, rather then strip the engine to fit it 'properly', he seemed to know what he was doing and could see ££ signs spinning so I agreed to it. Having seen how shoddy the rest of his work is I might strip the engine completely and start again.

That ain't gunna happen unless he breaks the chain then re rivets it again...
There is no way in gods earth you can remove the cam chain in 1 piece and loop it past the end of the crank unless you remove the oil pumps...
Time for this mechanic to get a taste of the black pudding over his skull....
ekky thoomp

[Overlord Neil]

I spoke to the mechanic last night, he's keen to 'help' but quickly distanced himself from putting his hand in his pocket as I've stripped it back, which is what I would do if I were in his position. But at least he wasn't a complete prick about the situation, he offered to do all the remedial work, but as its in bit in my garage and I've got the Blade on the road again, I think I'll do all the work myself.

Whilst its as stripped as it is, I'm thinking of doing a little head work to it. Back in the bad old days of running single cylinder 2 strokes, I used to be able to do a full engine rebuild in about 30 minutes, I had a nasty habit of over-revving my poor little H100 and went through a cylinder a month on average... Anyway, now that I'm older and far more sensible I ride a little more sympathetically. Question is, can you pull the head off the pistons and get them back in again, or do I need to strip the engine completely, get it on a bench and drop the pistons in from the top of the head and bolt the big end to the crank shaft?

I might go the whole hog and do a full strip down anyway. I'll probably start another thread but just as a heads up are there something that are worth doing over others, I'd like to focus on efficiency so I wondering if reducing friction through the running components with coatings is a good place to start, lots of small improvements through the engine, instead of one or two big gains?

[cobbadiggabuddyblooo]

Go hard on the boof head and get your cash back...
The head comes off in 5 minutes with 6 cap head style nuts under where the cams run and 2 long m6 cap head bolts you can see in the cam chain galley.
Barrels lift straight off and your left with the engine cases and rods poking up with the Pistons attached.
If you remove the barrels your up for another set of rings.
If you want efficiency to save you money, then you won't get more efficient than just reshimming and leaving the head n barrels bolted in place.
Otherwise your up for a few hundred dollars in gaskets, seals and piston rings n clips and the time just cleaning and what not.
If the motors still good personally I would just leave it.
Coating items will cost you possibly $130 a piston and add the running around time, things start to add up and what little you may save in efficiency won't really balance out in the overall lay out.
Head gasket alone is $100

Have a beer and think about it but I'm sure if you got your £350 back that would offset most of the costs..

[Rod.s]

Go hard on the boof head and get your cash back...
The head comes off in 5 minutes with 6 cap head style nuts under where the cams run and 2 long m6 cap head bolts you can see in the cam chain galley.
Barrels lift straight off and your left with the engine cases and rods poking up with the Pistons attached.
If you remove the barrels your up for another set of rings.
If you want efficiency to save you money, then you won't get more efficient than just reshimming and leaving the head n barrels bolted in place.
Otherwise your up for a few hundred dollars in gaskets, seals and piston rings n clips and the time just cleaning and what not.
If the motors still good personally I would just leave it.
Coating items will cost you possibly $130 a piston and add the running around time, things start to add up and what little you may save in efficiency won't really balance out in the overall lay out.
Head gasket alone is $100

Have a beer and think about it but I'm sure if you got your £350 back that would offset most of the costs..

Cobba, "Winter is coming" and he needs something to do during those great english winter months

[Overlord Neil]

Apologies for radio silence. Finally managed to spend a bit of time on the TRX that has been sat in a partially disassembled state since last summer...

To recap, the bike was sent to a local shop for a valve check, long story short the guy did half a job and botched that... I checked the valve clearances again and the inlets on #2 cylinder (furthest from the timing chain?) are way too tight in the region of 0.01-0.008 [should be 0.2-0.15 on inlet]. So I pulled the inlet cam out and tried to get the valve buckets out but they were 'trapped', the camshaft bearings have bulged and formed a burr that prevents the buckets from being removed. I've trimmed them back with a sharp blade, they were that slight, obviously removed any swarf and removed the shim buckets to change the shims.

Is this a common problem? The bike has 44k miles and was running prior to break down and theres no evidence of impact damage etc. Any thoughts?

[cobbadiggabuddyblooo]

Common sign of over tightening the cam caps... That mechanic is a complete numpty...
Bit of luck you can clean up the bearing surfaces in the head and caps with some wet n dry..
Re assemble with assembly grease and use a syringe to prime all the oil galleries in the head starting on inlet 1 , remove the bleeder bolt on the cyl 1 exhaust cam side until oil is running out of the bleed hole then re install the cams.
There's usually an air lock and inlet cam 1 cylinder is starved for oil on start up until fully primed .
Start the motor until oil is running freely out of the oil bleeder and screw the bolt back in place.

[nr]

I had something very similar when I looked at my top end. As well as the clearances being all over the place, the caps on inlet #1 were tight - when bolted down, the cam was completely seized. I used a steel rule to gently scrape the edges and the surface (the reason for using a rule was so I could keep the two seats parallel) and then rubbed it with wet and dry with some oil to keep everything smooth.It doesn't take much - just enough to open things up enough to allow it all to rotate smoothly again.

Worth saying - I've not run the engine yet Could all end up in a horrible explody mess on the garage floor. I did take the tip from here though, and primed the galleries before bolting it all back up again.

[Overlord Neil]

Managed a bit more time in the garage today (the up side to a rainy day!) got the clearances spot on, for the measurements, got the valve timing right and came up with a 'foolproof method' of setting the cam chain... well on my bike anyway.

Get the crank at TDC, install the exhaust cam in the right place [lines correct the head case] then install the inlet cam three teeth out clockwise. Put the cam chain tensioner in, give the crank a couple of spins and boom, job done. Doesn't make sense but it works.

Only down side of the whole venture was that the inlet's that were 'trapped' are still out despite being measured and shims changed. Either I got something wrong with my numbers (highly possible) or the bulge on the cam seat was somehow effecting the valve clearance, which sounds bad. There are two (furthest from cam chain) that are reading 0.13, so i might just leave it as it is and get the thing running again for the summer, but then again I might as well solve the problem whilst I've got the bike stripped down.

As a side note, I'm also doing the valve clearances on a CBR954 and found the cam chain tensioners are interchangeable, which makes me wonder if I'd be better off going for a manual cam chain tensioner? As I've just ordered one for the blade.

[Overlord Neil]

Latest instalment; Got the bike back together and tried a test fire with an auxiliary tank as the carbs will need fine tuning following their strip and rebuild with new seals and Factory Pro goodies... No Bueno, didn't even cough. Hmmm, doubting my own work I took the cam cover off to check the timing wasn't a million miles out again, still spot on. Did a compression test; 50 psi on both cylinders... As the bike was running [last year] before the whole debarcle started I can only assume the valves aren't seating correctly? Valve gaps are all good so *gulp* bent valves? But if the valves were bent you'd get no pressure build up at all?

I'm starting to think this might be a bigger job than I have time or money for, is anyone looking for a project bike? I could be very easily tempted to sell as it is and cut my losses, I'm not thinking a lot, try me.

[dandywarhol]

Did you carry out the compression test with the throttle fully open?

[Overlord Neil]

This might seem like a dumb question but why would you have the throttle wide open? Surely the chamber is 'sealed' at TDC so the throttle position shouldn't have an impact on compression ration... or should it, dumb dumb dumb.

[dandywarhol]

The throttle must be fully open to allow the maximum amount of air to enter the cylinder and register on the compression gauge.

You aren't checking the compression ratio, you're checking the compression pressure.

Reading previous posts, are you certain the valves are closing completely? - if they aren't, the compression pressure will be low