Project FZR fix up

You'll need a leak down tester, and possibly an adapter to suit your spark plug size

https://www.repco.co.nz/en/tools-eq...pplication/toledo-leak-down-tester/p/A1290063

https://www.dealsdirect.co.nz/product/engine-cylinder-leakage-tester-2-gauges/

 

Clearance's are correct

 

Stuffed? Having to fit new rings to a 30 year old motorcycle does not really qualify as stuffed. I would call that a service.

 

Those tests conflict, the best performance on the leakdown was the worst on compression

You could try some threebond engine conditioner down the plug holes and past the valves to remove carbon, you would obviously need to drain the oil afterwards.

Watched the video you posted of it running way back near the beginning of the thread, it was doing superbly given that it was running without the airbox.

I think it may need a good run more than anything, you've been through the carbs, coil replaced, plugs were a problem for you at one stage - if you have one cylinder not firing consistently, the carb to cylinder head boots could be loose and leaking air, if you've removed them at any stage, another forum user was spinning in circles with a lot of what you've been through, turned out to be that, or they could be cracked

I say get on it and ride it, get the idle circuit tuning done with the engine up to temp

 

When you did the leakdown test how did you determine TDC compression on each cylinder and how did you hold it there?

 

Probably not necessary to go to the lengths of cleaning the carbs back out again, check the fuel level with them on the bike first - that's the important one which might take some fiddling.

I think people recommend spraying start-ya-bastard or carb cleaner or brake cleaner on the boots to check for leaks with the engine running and if it climbs you have a leak.

If you do need to adjust the float levels to attain the correct fuel level, then worth checking that you have smaller main jets on the inside, depending on what series carbs they are 3LN1 or 3LN3 and the kits that you used as to what those actual jets will be. It won't rev out properly with them reversed, and that error has been noted in the supplied kits from keyster, the inner and out main jets were in the incorrect boxes.

I seem to recall you got a set of 3LN1 carbs as replacements, so float height is 16mm, which should yield a 9.2mm fuel level - if that float height doesn't yield a 9.2mm fuel level, then whatever the adjustment needs to be, lowering or raising the fuel level, that amount is added or subtracted from the float height measurement.

The float height measurement PLUS the fuel level height should sum to 25.2mm or thereabouts, so as one increases, the other decreases by very close to the same amount, which takes the guess work out of it and having to make an adjustment, reassemble, refit and refill to check the fuel level - only thing to remember is that the fuel level is the important measurement and the one to get correct

Last thing is the emulsion tube needles:
1st possibile setting - If they are OEM and all 5CT7 across all 4, centre clip on all 4 AND the centre two have the 0.5mm shim underneath
2nd possibile setting - If they are OEM and 5CT7 and 5CT9, then 5CT7 go on the outer two and 5CT9 on the inner two.
If you have used the keyster needles as replacements, then they are all 5CT7 then it's the first possible setting

 

Just to be clear, for anyone reading this thread, it is TDC compression that has to be used not TDC. Also, to the best of my knowledge, timing marks on 4 cylinder bikes usually only show TDC for cylinders 1&4, but you could just put a mark on the opposite side of the flywheel for 2&3 as they are 180 degrees apart.

 

Fizzers can dispense frustration by the bucket load till you find the cause, however being frustrated as we all know isn't ultimately helpful

There's been errors with main and pilot jets swapped, which is easy to do actually as they're the same type

Just go through your list, easy stuff first - fuel level, then check and adjust carb floats if necessary.
Spark, correct leads to correct cylinders - that's an easy mistake to make, and one out of left field but it has been done, has it run since you did the valve adjustments?
The inlet and exhaust cams can be swapped, won't run, but there won't be physical damage.
IN and EX is in the casting between cylinder 1 & 2, if you're checking the valve clearances, have a peak for that at the same time

 

Yeah coil's are for 1&4, 2&3
Are your fuel level's good ?