Hi chaps, excuse the noob questions but i did search 1st.

I bought my fist F2 a few months back and it needs a little tlc.
Mileage has just turned 24k and it needs its service.
So i found a genuine honda manual and went about changing all the fluids and filters. All went smooth.
At the same time i changed the manifold (usual rot) as it had a hole in it, despite this the bike ran fine and pulled strong before the change.
I've fitted a stainless replacement...
Now since all these changes the bike runs smoother BUT now has a drop in power between 6-7k then takes off.
Its also developed a clicking noise on tickover or low revs that cant be heard throughout the rest of the range.
My initial thoughts are its running lean at low revs and rich at high revs, and now the manifold has been changed the ECU is trying to adjust the timing slightly???(opinions plz?)

Now the manifold is an exact replica, so shouldnt be any change in back pressure, other than the obvious fact this one doesnt have a hole in it.
I've run the bike for about 200miles now, and not much has changed.

Your thoughts would be greatly appreciated.
p.s. ive already changed the usual CCTL, as it was gone when i bought it.

Thanks in advance

 

Read a few other posts, looks like a may need to clean the carbs and jets.
Whilst there check the valve clearences....???

 

The F2 is a carbureted bike. It does not have an ECU, just a CDI, which is not able to electronically manage A\F ratios, as that is done manually by physically adjusting parts.

Are you SURE??? Most aftermarket stainless manifolds are of a wider diameter, thus allowing more air through the engine. Did you remember to use a brand new manifold gasket? Most new ones don't come with it.


. . .why was it missing? If the PO had it off, that probably means he was trying to troubleshoot the same ticking sound you are. Engine ticks are generally caused by valves or lifters, and could have any number of reasons, all of which require you to open the thing up and stick your nose in there. Check your oil levels.

Additionally: did you have the carburetors separated from the bike at any point during your maintenence?

 

Whilst there? The valves are inside the engine, the carbs, and subsequent jets, are not.

It wouldn't hurt to clean the carbs and jets, but given that everything was running great until you did some basic maintenence, I was doubting that this was the issue.

 

Jonny,
Sorry im a tit and just realised ive put this in the wrong section (noob error i guess)
my bike is a 2002 injection model. Hence im hoping its intelligent enough 2adjust some of this itself.

The manifold atleast looked the same, i didnt measure it as it stated it was an OEM replacement, everything went back on with new gaskets yes, and i couldnt hear or feel any gasses escaping i checked straight after installation.

PO was not mechanically minded, he didnt know what the noise was hence i picked it up dirt cheap, but i did and changed the CCTL with a new genuine item within the 1st 100miles of ownership with new gasket, and it sorted all noises straight away, this noise has misteriously happened after service, i didnt play with any major parts etc, but did fit a K&N if that helps.
Heres the manifold i bought: http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=370261672794

Im assuming id need to pull off quite alot to clean the carbs fully, whats the possiblity of me doing more damage than good, or messing up the current tune?

Thank for your reply.

 

OH. You have an FS-2, not an F2. That's an incredibly huge typo


FI bikes do not have carbs. Fuel Injection and Caburetion are both means of creating an air-fuel mixture, so you either have one or the other.

That pipe has no specs on it. Do you have a make and model for it? I'm not intimately familiar with the European FS bikes, but generally speaking, adding a bigger manifold and K&N filter should lean out your mixture, but not to the point of malfunction. If I'm wrong on the FS bikes, you may need a Power Commander to correct the ratios to compensate for the increased airflow (the ECU is hard-coded, and doesn't dynamically adjust).

Otherwise, make sure all yoru vacuum hoses are routed properly. You may have a clogged injector or something. Also make sure you have a good tight seal at the other end of the manifold as well.

You should really post this in the European models section to get a more knowledgable answer.

 

if your ecu is anything like my 01 929 (which i guess it is pgm-fi) than it will automatically adjust to a certain extent with AEC thats how it warms up after all........and whats with the back pressure myth rearing its ugly head again.....

 

Cheers chaps.
And yes cowboy it is a pgm-fi model so being auto choke etc etc, thats where my guess that it would adjust somewhat the changes itself.

Johnny - All the seals around the manifold are ok that ok can see, hear and feel. I cant think it would be a dodgy injector as it was running sweet before hand and then instantly not after. i also emptied what little fuel was left in the tank out and put new in.

I did think ooh, might need a Power Commander now, as the setup has i guess changed, and in affect if it were an older bike it would need setting up again, so maybe a Power Commander would smooth it out.
Any experience with these???

Whats the best way to get an admin to simply relocate this thread, rather than repost the whole thing??
Cheers.

 

BAH! You didn't say you had a power commander in there, and I assumed you didn't. You changed the airflow through the engine which could absolutly cause it to get dodgy at certain RPMs. You don't need to replace the power commander, just take the bike down to the dyno and have them make a new map to upload into it.

 

pc ftw....my best guess is the new manifold has a slightly different diameter or the intial angle is different thereby increasing or decreasing exhaust velocity.