ZRX1100 - no go above 6000 rpm

[durcott]

Hi Folks - ZRX1100 newbie here.

I have just got a '98 ZRX1100. The first few open road runs were disappointingly rough, but the low rev range is now running smoothly after 2 tanks of fuel and a bit of carb cleaner run through it.

The bike misfires and practically gives up above 6000 rpm in top gear. If I snap the throttle shut in this state, I normally get a pop, so i suspect some unburnt fuel in the can.

It was reported as running well throughout the rev range by the dealer. Of course he would say that, but I don't really suspect this to be BS. The bike ran fine on a test run, but that was in town.

There's already quite a lot of traffic here on things that will stop a ZRX running perfectly - so I already have plenty of things to check.

However, I was wondering if anyone knew what is happening in the carbs at around 6000 - 7000 rpm?

It seems curious that the engine is sweet up to this point, and then loses interest. I wondered if that pointed to anything interesting?

Cheers

Jeff Adams

[Burchy]

Take it back to the dealer to sort out

[brakeline]

Burchy is right, take it back an say a few cross words to the dealer, and I'm sure he will sort it.

[durcott]

Hmmm - Easier said than done - there's 100 miles and an expensive ferry crossing to take away from the benefit of a free repair.

If it weren't for that, I'd be on his case - but then the price I paid was very low, so I'm not foaming at the mouth just yet.

But I have found 2 very similar threads on the forum now - and i have found plug cover No.1 is corroded and loose, which seems to be a ZRX special problem.

[Burchy]

Which dealer did you get it from? 100 miles from Radstock could be Plymouth to Wolverhampton!!

[durcott]

It was Bert's Motorcycles at Ryde (I kid you not) on the Isle of Wight.

As far as my spies on the IoW tell me, considered to be one of the good guys.

[firmhand]

Hello durcott, check the airfilter housing cover (under seat) is properly seated and tightened up, can cause all kinds of running problems if its not.

[brakeline]

change the plug covers, worked for me

[durcott]

New set of plugs and covers coming from the dealer

I'll let you know how I get on

[brakeline]

hopefully it works

[durcott]

;D Yep - that was probably it.

Changed number one plug and cap and it's a different motor.

There's still a flat spot or two, but only if I have the throttle wide open. I guess the trick is to feed it in as the revs rise?

After a few miles, 10000 rpm was got to fairly quickly in low gears.

I think we're getting there - thanks so much for the hints.

Jeff

[brakeline]

Magic

[durcott]

Hi Folks - rather than start a new thread on something trivial:

I've got a plug cap here - marked NKG SB05F.

As far as i can tell, this is NGK's longest plug cover - but i find it's a tad too short, and the seal on it feels to me like it's going to bind on the cylinder head hole.

But - folk have said - 'use an NGK plug cap'.

Are people using the SB05F, or a 'special'?

Sorry for the dull question :-(

[brakeline]

cant help with that I'm afraid, bought mine from a dealer and shoved them on. they worked . dont know what make they are though

[m8withblackbird]

Well I've heard it all Brakey giving sound advise Top Man, Top Man, can you please tell me why my Honda Blackbird stutters & misfires at 11,000rpm or 180 mph in top gear ?