Ime pleased to announce that the rev 3 is now fixed !
After much stuffing around fixing little things, none of which sorted out the four stroking problems, we fitted a new stator and BINGO ! she reves out like a champion. Its now running sweet and will only get better with some fine tuning. I have now been told that rev 3's are prone to such problems.
I think it cost around $300 aust. and worth every cent of it. Time to go riding
All the things you have mentioned are pointing to a lean mix as you say.
I am of the belief that carburettor manufactures set a spesific float level for a very good reson, and any changes to it will affect its performance.
Ethanol is a great fuel and has some good points but it has two main drawbacks, firstly you need more of it to make the same bang and secondly it absorbs water from the air readily causing gelling with some premixes and promoting oxidation. By adding bio blended fuels without jetting changes you are effectively leaning the mix a little. Personaly I only run 98 octane or higher fuel in anything that I want to perform.
I too have noticed a marked inprovment in the engines problems after the carby work ie. it revs heaps harder.
I am waiting untill I get some new parts before I try to tune it any further, such as a new air filter to replace the torn one, new inlet manifold to replace the perrished split and possibly leaking one, some reeds to be sure to be sure and lastly a throttle cable to replace the worn out prickley and kinked cable that is on it. The next check will be the ignition timing.
All the obvious problems with the rev 3 i am working on are pointing to a lean mix like yours.
Keep you eyes out for the XR 1200 single make series this year it should be good racing.
A couple of big names have signed up allready.
I bought a road going one just befor christmass and if its anything to go on the racers will be fantastic.
There is something verry satisfiying about going up the inside of an R1 on a roundabout on a big twin,sat bolt up right pretending your not trying, depending how long the next straight is most of the time they come back past so you can do it again at the next twisty bit,Deep joy.
How did the word harley make it into the superbike area? challange a r1......... yeah sure , I bet If you had a decent mufler on the harley you would hear the r1 rider dying with laughter!
Yes the Rev 3 carby is leaned forwards lots and a front down attitude makes it worse. If you do a search on the Beta Forum you should find hundreds of postings on this issue with many suggestions for how to avoid losing petrol out the overflows. It might even be a pinned topic.
What is "1 1/2 to 2 1/4 air bleed"?
By that I mean the air adjustment for the pilot circut.
I have seen this problem in my friends 2001 Rev 3 and his problem was piston ring blow-by. Fixed with new rings.
Hard to diagnose yours via forum postings though - yours may be stator failure. The stator problem can cause an effect very much like rich mixture above a certain RPM because the ignition cuts above a certain RPM, causing misfire.
Standard carby settings are fine. Most people go through hours of changing things on the carby, only to find that it was not the problem.
There was a good reason the float height was set low and you will find out why when you ride the bike more. Set the idle mixture screw to suit your bike. The standard setting or anyone elses setting is only a guide.
You didn't list the pilot jet size and that is the thing that people commonly change.
Was the float set high to stop it from overflowing when on steep angles?
also ile post the pilot jet size when i get back to the shed.
I am working on a 2001 rev 3 270 that a mate has just bought, the bike has been neglected somewhat and ime trying to clean it up and get it running as it should. Its biggest problem is that its 4 stroking, from halv revs and wont rev out far.
So far ive fliped the reeds over to get them sealing again, cleaned the carb, reset the float height wich was out by a long shot ( low ) as per owners manual but its far from running perfect.
Mikuni 26 / 683
145 main jet
5c23 needle
3rd clip
1 1/2 to 2 1/4 air bleed
1 1/2 idle mix screw
what ime looking for is atleast someone ho knows the base carb settings including the idle mix screw,
also some advice on what the problem is likley to be.
Rev 3 270 4 Stroking ?
in Beta
Posted · Edited by on_one_wheel
Ime pleased to announce that the rev 3 is now fixed !
After much stuffing around fixing little things, none of which sorted out the four stroking problems, we fitted a new stator and BINGO ! she reves out like a champion. Its now running sweet and will only get better with some fine tuning. I have now been told that rev 3's are prone to such problems.
I think it cost around $300 aust. and worth every cent of it. Time to go riding