underpowered

ok i dont have my ful licence so im not sure about the power of FZR's but my m8 has a gpx 250 and he took my FZr down the road and he says he can only get 80mph (120 -130kph) out of it and it wouldnt pick up anymore speed wot eva he did.

im gonna try changing the oil , oil filter and spark plugs and then see if that makes any difference.

does anyone else think its something different.

its the FZR 250 89 3LN

 

When I had the FZR and my son had a GPX mine was slightly quicker, I think about 10hp more for the FZR but the power delivery is different.

Try the plugs first, but it sounds a bit more than that .Check the compression, 160psi new, under 100psi will be lucky to start. Between that will be ok...

Other than that, check the fuel consumption. Should get around 170k before switching to reserve. That might indicate carb problems, air filter, etc.

The only thing that I could think of after that is if the cams have been out to do the valve shims, the cams may have been put back a tooth out.

P.S. Check the EXUP valve is opening, are the cables broken?. It should be fully open by 10,000rpm....

 

well the wires move when you open the throttle to above 4k rpm but its got bigger jets in so makes a popping noise wen you release the throttle and top end speed of a gpx is 100mph while a fzr should reach that about 2 seconds quicker and has a top end of 111mph or 180kph ish i think :S

my mates says my fzr reaches speed quicker to 60mph but hits 80mph and it sits there at 10k rpm

so ill get the spark plugs and oil tomorrow and see if that work

 

And check the air filter likely she is running rich and needs a balance

 

I'd be checking those EXUP cables.
Nice healthy bottom end power but running out of steam in the top end means the EXUP valve might not be fully opening.

Does the bike pull well above 10k (through to 17-18k?) rpm in lower gears?

 

Unless the bike has been on a dyno, putting bigger jets in is prob not a good idea. These bikes have a tendency to run too rich as the carb wear, and bigger jets would make it worse.

Take the exup cables off and tie the valve fully open, which is about 1/4 turn clockwise. Then go for a ride and see what the difference is. Bottom end torque will disappear though. I expect a report back from you soon <!-- s --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt="" title="Very Happy" /><!-- s -->

 

well my m8 says its onli top gear that has problems so do you think it might have a 33bhp restictor kit on which is useless to me without paper work and i wont be able to do much over the next week got alot of work god help me so ill have a report in just over a week

 

If its running, don't f*ck with it unless its not your daily rider.

If you're happy with it, then don't let your friend sow the seeds of doubt.

 

so you think i should onli change oil oil filter and spark plugs and leave it there then

 

Don't even change the spark plugs unless they definitely need changing.

I only say this because a few people have had plugs snap during the removal process.

IMHO, you and your mate should get a guernsey on another 89 FZR if you really want to compare notes.

 

well my dad is more than capabale of changing spark plugs and i have done a motorbike maintainence course lol and well we dont no when the spark plugs oil and water was last changed or even if there is any coolant in the water so we changing all that stuff and dats it apart from the parts it need to pass a MOT lol

 

When you pull the plugs out make sure to put some anti-sieze compound on the threads of the new plugs. I had one that was so tight I thought it was going to snap. But it did come out in the end.

I used loctite brand "nickel anti-sieze". Its good for around 900deg C so it can also be used on exhaust header bolts, etc,

 

I'm not suggesting you or your dad is a numpty with a spanner.

The takehome message is that these bikes are getting old and some have been flogged senseless.

Through no fault of their own, people have had spark plugs snap mid-removal.

 

Very few though. If in doubt try putting in a bit of CRC or INOX or other spray lubes in the threads before removal. You will never know if you don't try

 

What hoops do you need to jump through to pass the MOT?

 

well for a mot of wot i know it needs gasets a tail light bulb and indicator bulb and fork seals and i have bought 4 incators and oil just need to get a oil filter.


i got a 1hx engine is that the same engine on all the 3ln's?

 

@badger: you're in the UK yeh? I saw an engine go on UK ebay for $A117 from a wrecker/breaker. Over here we pay in the vicinity of 1000 dollars <!-- s --><img src="{SMILIES_PATH}/icon_sad.gif" alt="" title="Sad" /><!-- s -->

I have a 3ln engine and a 2kr engine side by side on my workbench at the moment both stripped down one step off splitting the cases.

I can't see a great deal of difference between the two.

The main significance I have seen is that the 2kr oil filter resides inside the engine - the 3ln has an external spin on type. They have differing oil pans to accomodate this of course.

The other thing I noticed is that the 3ln has two oil spray nozzles situated to the sides of the 2 and 3 crankwebs - the 2kr does not.

The cylinder head removed from each has the same designate whereas the engine casing is not.

I expect to transplant ancillaries (starter, clutch etc) across shortly and I don't anticipate any issues.

If anyone wants any photos of these engines (including a completely pooched cylinder <!-- s --><img src="{SMILIES_PATH}/icon_redface.gif" alt="" title="Embarassed" /><!-- s -->) let me know.

 

so i take it the 1hx is the one that is on all 3ln's then.


also wen i open the throttle and look into the carbs the carbs seem to be opening up at different times so are they all surpose to be moving the same amount all the time or are they pose to onli go 2 at a tym.

 

bagder, changing your spark plugs and oil won't do much at all. Unless, that is, you've got a dogy spark plug or something. I'd still recommend changing them as part of regular service - it's unlikely that you'll snap a plug.

My theory is that your mate is full of ****. my fzr also has no guts in top gear, and so does everyone elses. there's probably nothing wrong with it, it's just a 250cc.

Maybe you should consider taking your bike to a mechanic and getting a tune-up to set your mind at ease.

 

well im currently trying to get it through its MOT and my mate was correct it didnt have its full power because the exhaust was blowing and therefore there wasnt anoth backpressure for the value to work so it was only opening half way im hopeing it will pass its MOT which isd the 3rd attempt bloody forks are too stiff so just bought a new set of forks lol £60.00 so sofar i have spent about £800 with buying but it be worth it wen it passes <!-- s --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt="" title="Very Happy" /><!-- s -->