H1 flat spots in rev range

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Oshar
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Joined: Sat Sep 02, 2006 2:00 am
My Bike: tomos moped
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H1 flat spots in rev range

Post by Oshar »

Hi All,

This is my first post and I’m not technically minded so go easy on me :smt001

So, I’ve owned my H1 for about 3 years now. After 6 months she would not idle or start properly. Due to financial trouble, I put off fixing the bike for a while and rode it every day to and from work as it was my only means of transport.

After some time the exhaust developed the usual holes due to being made from mild steel and my all weather riding. I purchased some down pipes from Ebay and these also developed a hole. I managed to find a company (can't remember who but I can find out for those interested) that sold down pipes for around £240.

I thought it was time to spend some money so I sent the bike in to have “the works” done while I ordered the exhaust. The carb rubbers were the first thing to be replaced and the bike now idled well enough and started ok. I proceeded to spend more on brakes overhaul and new pads, new forks, new head bearings, new clutch cable, new battery, new rear tyre, etc

The following month I proceeded to fit the down pipes myself. One cylinder made a "ticking" noise that sounded like air was getting through. So after fitting and refitting the exhaust 6 times I was convinced that the noise was not from the down pipes. :smt013 What struck me strange was that this noise only appeared after fitting the exhaust :smt017

So far I have spent around £800 fixing her (Inc parts).

The bike still has the "ticking" noise in one cylinder and will not reach its top end speed. It also has flat spots in the rev range. My mechanic has told me that fitting the new exhaust could affect the bike and I would need to have the bike dyno’d.

So my dilemma is:
What is causing the noise in one cylinder?
And does the bike need a Dyno or is the flat spots related to the ticking noise?

So, do I have the bike dyno’d or is there something wrong with the engine?

PS, the Dyno will be at PDQ at a cost of £150
http://www.pdq1.co.uk/

Thanks, and Regards,

Frank
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masterofinsanity
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Post by masterofinsanity »

hi frank ! :smt006 is it a race system you have fitted?? if so then yes it will need dynoing check the headers are sealing properly at the engine, there should be copper washers to help seal the headers that usually get lost, if you are missing one this could cause the noise you are hearing, but i would do a compression test also , could well be a broken piston ring.
Don't forget people there is more to the zxr400 than this forum... check out www.zxrworld.co.uk also.
Oshar
Posts: 8
Joined: Sat Sep 02, 2006 2:00 am
My Bike: tomos moped
Location: South London

Post by Oshar »

I have replaced the washers with genuin kawasaki ones and used small dabs of copper grease to hold them in as they would fall out when fitting the exhaust.

The downpipes are not a racing system, but the end can has been changed by the previous owner. (no make but sounds good)
The company i purchased the downpipes from was http://www.dkmotorcycles.co.uk
Would loosing compression cause any smoke or other effects? Im not getting any smoke, and the noise seems to come and go. today its being quite good. :smt017

How much would a compression test be?
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masterofinsanity
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Post by masterofinsanity »

dkmotorcycles ooooerrr!! :smt009 get a comression tester from your local car accessorie outlet about £15-£18, figures are in the manual.
Don't forget people there is more to the zxr400 than this forum... check out www.zxrworld.co.uk also.
Oshar
Posts: 8
Joined: Sat Sep 02, 2006 2:00 am
My Bike: tomos moped
Location: South London

Post by Oshar »

I’m not having a good week. My bike yesterday has now developed a new fault. When driving along, the bike would stall and stutter (also backfiring) and the lights would also die. For some reason the rev counter goes mental too. I dip the clutch to start it back up and again it would do the same. It’s like riding a bucking bronco.

I know it’s an electrical fault, but could this be a regulator rectifier issue or just bad wiring somewhere?
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masterofinsanity
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Post by masterofinsanity »

sounds like the regulator mate, usual symptoms.
Don't forget people there is more to the zxr400 than this forum... check out www.zxrworld.co.uk also.
Oshar
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Joined: Sat Sep 02, 2006 2:00 am
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Post by Oshar »

Ok so I have an update for those interested.

Firstly, took the seat off check the battery and the positive was loose. That’s what was causing the bike to cut out etc :) so with one problem down I was ready to take the bike for the rolling road yesterday.

All I can say is WOW. Nick (I think) at PDQ is the dogs. He put the bike on the machine and ran it. Told me she wasn’t well and to come back in 2 hours. So I went and got a bite to eat.

When I got back he told me he had the carbs off twice. The floats were getting stuck and the person that put them together last was an idiot ...but could also be due to sitting in the garage too long :(

BHP is now reading 65 and I’m thrilled. She idles well and runs like she did when I first got her...its scary again :D

Torque has also increased from 21 to 28 lbs/ft

So, now she’s sorted, if anybody wants to buy a ZXR400 so I can upgrade to the 750 let me know.

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RedexRobB
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Post by RedexRobB »

Thats good news mate, how much was the dyno time and sorting the carbs?
Oshar
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Post by Oshar »

Dyno took 2.5 hours at a cost of 180 including VAT. (was charged for 3 hours labour)
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