Hi All This is driving me MAD , Help Me Please !

I have a 2005 Rev3 125 with the Delorto carb Its starting on 4th/5th kick take the choke off and away I go . Then half hour or so later there is no bottem end the bike stops and will only start on the choke . I have taken the carb off and was unable to see through the pilot jet , cleared jet and the rest of the carb refitted then it happens agian and agian. Unable to find any muck in the carb, fuel is fresh. Fuel cap breather is Ok .

Am I running the bike to lean at two half or so turns out on the air screw . The coil has been rewound . Next step is to start pulling my hair out !!

its the crankcase seals sucking in air.most likely mag side.

Not sure how bad crank seals are clogging the pilot jet? You need to clean everything. Change fuel filter, clean carb screen, new air filter with greased sealing surfaces. Check air box boot for leaks and new fuel. New fuel presumably w/o water in it. 2nd order, Theres also the top of the carb, Check the seal of the top cap and proper cable routing.

Somethings getting in. Usually from one of the filters not doing its job.

i dont know if the rev 3 has a filter in the tank like the evo but mine blocked section 1 at a trial it would trickle through but as soon as the bowl and in line filter emptied it died might be worth a look

Yes there is a filter on the fuel tap I had to remove the tap as it stuck shut I was surprised at the goo on the filter gauze

thats got to be worth a look

So has this carb ever ran right? The dellorto was not the original carb.

I'd start with having the carb ultrasonic cleaned and then fit new o rings etc, give the tank a good wash out with fresh fuel, clean air filter and then fit a clear (see through) inline filter to the fuel pipe.

How about the fuel tank breather?

Many Thanks To All for your Help I shall hopfuffly be in the shed this weekend. Will report back with news.

Good job I have a trusty old Ty Yam I drag out for a ride this weekend !

If you look at the float valve (the end where the fine wire clip engages) with a magnifying glass you will see there are two groves that are slightly different. The fine wire must engage in the smaller groove that goes all the way round, not the larger cut outs that only go part of the way round.

For some reason the wire often seems to find its way into the wrong groove. You will be amazed at the difference having the wire in the right groove will make to your bikes performance.

Check the exploded diagram on the Dellorto UK website.

Thanks Dad of 2. This Rings A Bell I will have a look soon . When I first got the bike I went through the carb to remove a restricter that the last owner had fitted and make sure it was all clean in side and when putting back together I put the floats upside down and try to get the bike to run , it would not go as the float valve was pushed up realy tight .