ZZR250 Problems a plenty

I have asked this question some time ago in relation to the 3-4k revs flat spot.

1st, I have carried out the following since:

Emptied and cleaned the fuel tank, drained both carbies a couple of times, used a bottle of carbie cleaner during the course of three tanks, without much change to the problem. Do you think my only other option is, remove the carbs and clean the jets with a fine wire.

2nd, Today as I was cruising at 60Ks and felt the bike jolting slightly, what could this indicate?

3rd, Some time ago I had the bike on the centre stand to check the chain and I noticed the chain is relatively loose but within limits however, when I rotate the wheel a full turn and inspect the chain again, the chain is tighter. The rear sprocket is in line with the wheel and the teeth are ok. I have been lubricating the chain and cleaning it regularly but for some reason the chain links are ok for a length and tight for another length, can you suggest any reason for this, and what is the best cause of action?

I have considered replacing the chain and sprockets, front and back, would this be the answer, and do you think this may be also responsible for the jolting or cause any other issues that are not yet obvious at this stage?

I have been quoted $300+ for the chain and sprocket replacements and $100+ for the rear brake pad replacement. I was also thinking would it be in my best interest to change the dampers in the wheel axle area, and do you think the quote is a fair price?

Bike history:
93 Model, 18,200 kms, purchased last July 08, I have clocked 5k kms since then. The bike was not ridden for about 8 months before I bought it.

Cheers.

maybe check the fuel switch and the vacuum line that goes to it as well as the fuel line......the fuel switch has a diaphragm in it which can cause many problems if faulty....
as for the chain and sprokets it suggests that the chain has tight spots, if you have some mechanical knowledge or a friend that can help you could pick up the parts for around $170 and do it yourself.....the brake pads you can get for $50 and are very easy to do.....i would probably replace the damper rubbers as well since you would have the rear wheel off and easy to do.....the quote seems around the average price but it's more fun to do it yourself

The problems are now all fixed.
The carburettor vacuum hose required re-sealing and re-tuned.

The chain, sprockets and rear brakes were replaced with new parts.

The front sprocket is reduced by 1 tooth and rear added 3 teeth, to increase acceleration from 1st to 6th gear and a much quieter ride at 100ks +, it will interesting too see if the economy increases.

Thanks for your suggestions

The problems are now all fixed.

good!

The carburettor vacuum hose required re-sealing and re-tuned.

The chain, sprockets and rear brakes were replaced with new parts.

as long as that fixes the problem!

The front sprocket is reduced by 1 tooth and rear added 3 teeth, to increase acceleration from 1st to 6th gear and a much quieter ride at 100ks +, it will interesting too see if the economy increases.

Uhhhhhhhhh, subtracting front teeth and adding rear all mean that the gearing is shorter which by all means, yes does give better acceleration, but at the cost of higher rpm at a given wheelspeed in any gear and im guessing a proportional increase in fuel usage.

Well it wouldn't be worth going the other way as the ZZR would basically be revving on the spot.

I'm interested about the quieter ride at 100kph bit though, my GPX used to rev its tits off at 100kph and eventually my hands would go numb.

I'm guessing fuel economy would drop slightly, but if you're getting 80mpg instead of 90mpg who gives one?

Mick

Well it wouldn't be worth going the other way as the ZZR would basically be revving on the spot.

I'm interested about the quieter ride at 100kph bit though, my GPX used to rev its tits off at 100kph and eventually my hands would go numb.

I'm guessing fuel economy would drop slightly, but if you're getting 80mpg instead of 90mpg who gives one?

Mick

I dont think you can get a quieter ride at 100kph, its usually around 8,000rpm which isn't a relaxed cruising rpm and does get annoying on long freeway stretches. (and tends to upset drivers with their windows down if you have a Two brothers exhaust )

Is fuel economy an issue on a zzr?? Im still constantly amazed at the economy of my gpx even after a good run through the hills.