Hanging a valve.

[deathcomesarippin]

Out of the process of elimination so far (still have to check the compression), But im sure a valve is hanging open in one of the cylinders. my question is, am I going to have to drop the engine to pull the head off? I would like to keep it in the frame.

[reelrazor]

The head will come off in the frame. It aint fun, but it is do-able.

Far preferable to let it drop down/hang on the rear engine mounting bolt.

If the valve(s) is just out of lash clearance, there will be no need to pull the head.

If you actually have a valve that's stuck in its' guide, and it was running when such occurred.......well, you are going to have to pull the engine anyway.

These are 'interference' engines.....waaaaaayyyy 'interference'.

If a valve hung/stuck while running, that valve is now bent, head is likely cracked. Piston is smashed and rod is bent.

[deathcomesarippin]

dam, well maybe its time for that 660 conversion. but im going to run a compression test later today..when the tool gets here..but what makes me think im having a valve problem is, when im turning it over and i put my hand over carb #4, its hardly making any suction, with both sets of carbs I have. It also back fires hard out of the exhaust like the raw fuel is just sitting in there, so it could be a valve, could be piston rings? It dosent smoke so im not thinking it would be piston rings, now im hoping its not a valve problem.

... Anybody know of a a good cheap engine stand for these engines?

[gre3nskeeper]

You shouldn't need an engine stand. They're light enough to lift and plop right on a work bench.

I hope its not major head damage. But if you decide to go down the 660 route, I have a YZF top end in the for-sale section.

[lamer]

Out of the process of elimination so far (still have to check the compression), But im sure a valve is hanging open in one of the cylinders. my question is, am I going to have to drop the engine to pull the head off? I would like to keep it in the frame.

Sorry if im missing something here but , What "process of elimination"?

If the valve(s) is just out of lash clearance, there will be no need to pull the head.

Have you checked/adjusted the valve clearances/lash?

when im turning it over and i put my hand over carb #4, its hardly making any suction, with both sets of carbs I have. It also back fires hard out of the exhaust like the raw fuel is just sitting in there

Is the intake on #4 cracked/split leaking?, Is the screw on #4 intake (where you connect the vacuum gauge) in place? both conditions can cause similar symptoms to what you are experiencing.



Did you buy those 1989 carbs? viewtopic.php?f=8&t=9196

[deathcomesarippin]

No I didnt end buying the 89 carbs, I got ones from a 95. Im sure there are no cracks in the intake,i have check it again and again, and the vacum screw is in there.

No I havent adjusted the valve clearance/lash, ill just might as well do that first and see what happens.

[97fzrnoob]

Have you figuered your valve problem yet? I had one that was bent, but bike still ran ok ended up replacing the whole head and got everything fixed. I do have the old head still that has 15 good intake and 16 good exhaust valves if ya need some spare parts.

[racerd14666]

check the valve adjustment first i dont think you did any hardcore damage cus you didnt mention any funky noises like a bunch of change bouncing around, random whistling or smoke just every were, after you confirm the valves are adjust correctly you can verify nothing is bent broken or has a hole in it with a leak down test. most backfiring is caused my excessive air in the exhaust not so much fuel, you only really get it to back fire from to much fuel/air mis is after the pipes are damn hot and you cut the ignition while the motor is still spinning a decent rpm like on a dyno or screaming down the road, its not that uncommon for bikes of this age for the carbs to be dirty/incorrect jets/mis-tuned what have you specally if you didnt adjust them after u swapped them cus every bike runs a tad bit different, the low compression/vacuum on one cylinder wont directly cause a back fire cus if its not sealing enough to suck any fuel air mix in it cant push any out into the exhaust to go bang. we can help pinpoint whats causing by u telling us more info like what you have for a setup like air box and filter, exhaust and what not, and how what were and when it dose it, like revving it up in the parking lot chopping the throttle it back fires ect. but if you do need a head i do have a few i can sell you.

[racerd14666]

I do have the old head still that has 15 good intake and 16 good exhaust valves if ya need some spare parts.

i dont think you have a fzr 600 head cus there 16 valve heads........

[DonTZ125]

[97fzrnoob]

its an fzr head, just got wonky on the math (4th straight 15 hour work day and too tired to sleep). 15 valves and buckets are good, the head and cams are toasted.