j model build thread, finally started

Pyke13 said:

The rubber thing in the rocker cover for the timing chain, its name escapes me.
is it important?
mine is in 2 half’s, ive seen contradicting advice. Can i just grind the pegs off and forget about it?
or should i borrow one out of another engine?

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I'm in the same boat.

The shop that worked on my engine mentioned this rubber part (120535B) was damaged and removed it. The purpose was to reduce cam chain noise. A damaged one, or deterioration from age can cause oil flow restriction. Mine had no wear marks like a chain guide.

Supposedly you cant replace it. It's integrated into the valve cover. No way to bolt on another.

Its held on with 2 dowels, the rubber just pushed over it.
i cant remember if its the M or N race kit manual says to remove it and grind off the dowels.
cam chain noise isnt important on a race bike i guess. a race engine probably gets opened up lots more often than a toad engine.
im not sure if i want to take the chance running without it or not

Just an inexperienced speculation, but that does not look like the cam chain has made too much contact. It's still in its oem shape. It started life with those grooves from what I understand. It looks like someone used something to press, or hammer it back on though judging by the marks in the center. The previous owner may have neglected a cam tensioner replacement.
Mine had 0 marks, and I smack the rev limiter occasionally. It just fell apart from the constant heat cycling.
The chain slack that would cause damage to that part happens on high rpm deceleration.

Here is a video on installing a new cam chain guide:

He also has a video showing all the pieces found in the oil pickup screen.

@Pyke13 looks like it might be in stock here: Fowlers Parts

mattv said:

@Pyke13 looks like it might be in stock here: Fowlers Parts

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Slorg442 said:

Just an inexperienced speculation, but that does not look like the cam chain has made too much contact. It's still in its oem shape. It started life with those grooves from what I understand. It looks like someone used something to press, or hammer it back on though judging by the marks in the center. The previous owner may have neglected a cam tensioner replacement.
Mine had 0 marks, and I smack the rev limiter occasionally. It just fell apart from the constant heat cycling.
The chain slack that would cause damage to that part happens on high rpm deceleration.

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Thanks for your help. Before i order, it says its for a p5. I assume all P models will be the same but is this one of the parts thats the same over the whole zxr/zx7r range?

Thanks for that. I hate trying to work out part number pages

had a look inside a parts engine, think its a 9R. Found one but its slightly different, saves me buying one.
last year i was sub contracting as a stonemason and money wasnt an issue. This year i am now my own company. Ive spent more on tools than ive earned in the last couple months. So as you can imagine spending on motorbikes is not the priority it used to be. As mentioned in another thread i moved country from scotland to england just before lockdown. Im now just Trying to build my business back up in a new location.

Whats green valve springs all about? Found them in one engine
The cams in that engine also look different, the finish on the shaft is different to the other 9r engine i pulled the cam cover off.

It turns out green valve springs are standard on 9R engines. The differences must just be B1 and B4 engines. Thought i had caught a break and got higher rpm springs

Pyke13 said:

It turns out green valve springs are standard on 9R engines. The differences must just be B1 and B4 engines. Thought i had caught a break and got higher rpm springs

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Green valve springs are stronger than unpainted valve springs. (LOL)

For the 9r head, I think a mod for them was to use the zx7 (k/l/m) dual valve spring to increase the rpm. The J model goes to 12k rpm and the k/l/m all go to 12.5k rpm. In conjunction with that, they ran the L igniter(CDI) to allow for the higher rpm. Though, I would want the crankshaft to be lightened and balanced to run that higher RPM. Throw in lighter and stronger pistons and con rods. Add hotter cams. Though, I don't know off the top if the 9r makes it's power in the upper rpm range to warrant all those extra upgrades.

Problem occur when the 9 engine is ran at high revs, the oil doesnt drain back into the sump quick enough. Theres way to cure it. I know someone building a 925cc engine with race kit spec cam regrind and lightened and balanced bottom end, i also think their running efi. I will share some info here when i get it.

Did the same with my SES fairing stay 😎

Definitely like the longer levers on older bikes. Just looks right.