Forum

[spence]

Hi all,
I have an 03 classic bullet didnt get to ride it much at all last year but now going through it ironing out all the niggles ready for this years riding.Bike starts really easily and settles into a nice steady tickover but as soon as the engine gets warm the slightest touch of the throttle sends it revving madly and then it gradually slows down and returns to tickover.Im suspecting the original mikarb is worn or wrongly jetted.The previous owner made a number of improvements?to the bike which i am slowly putting right.This is next on the agenda.Im wondering if its worth messing about with the original carb or buying a direct replacement and using that as a starting point if you add up the cost of parts to refurbish a mikarb jets throttle slide etc is it worth it?By the way yes i have done all the usual checks throttle cable correctly routed not trapped etc.Any thoughts anyone on original problem and on purchase of a new carb question ?Yes it will be indian made but so was the original!

[Norm]

Spence, the slide is sticking for some reason, either cable or binding inside the carb which is unusual, unlike an Amal that can distort the body. Needle sticking in the mainjet?, it is something simple and the Micarb is a reasonably robust carb that shouldn't give too many problems

[spence]

yes thank you for your reply norm,would it be usual to see much wear in one of these carbs when bike has only done 14000 miles? Mind you havent stripped it yet but im not familiar with these carbs. Im actually looking forward(in a perverse kinda way)to removing carb and solving problem.

[Alan R]

Hi SPENCE------- 350 or 500 ??-------------On E.Bay a brand new carb is about £45-50 whilst a used one will be about half that............ Our hosts have 2 off VM28's listed at £35 approx...........My advice is not to bother tweaking or adjusting but do a complete strip and check to see just what the previous owner has actually done....You'll also need to bear in mind the set-up of the bike ie}----Standard or "improved" and relate the carb setting to that particular condition............As it's been standing for some time you can expect the primary fuel drillings to be gummed up or partially blocked with Ethanol by-products......Have a look at this >>>>>>>>>>>>>>>>> http://www.youtube.com/watch?v=xhGyK6MpkOQ .............Drain the fuel tank and check for water, rust etc.....If you can afford it have the tank lined with E-10 proof lining....Fill with fresh petrol........As you say these are a robust and simple carb with a good history of service......Read our hosts notes in the Tech notes section on the left of this screen-----------DON'T POKE ANY OF THE HOLES WITH FUSE WIRE ETC !!!! It's NAUGHTY !!!!!

[Norm]

Spence, I wouldn't expect to see any wear on a Micarb with only that mileage on it, there is nothing in them they could not be anymore basic than they are. I'm afraid you won't get a lot of thrills ripping into it. Another thing that could be causing problems if it is a 500 is if you have the carby vertical the cable can bind, lean the carby slightly outwards and it will help. If it is a 350 this isn't a problem because the carby is lower

[Alan R]

----------or you could fit my tank "riser" like this >>>>>>>>>>>>>>>>>>

[Alan R]

SPENCE------------ whereabouts are you ??-------If near Shropshire I have an Ultrasonic Cleaner that you're welcome to come and have a "freebie" clean....can help you with float height setting etc...

[spence]

Thank you both for your reply,alan r the bike is a 500,unfortunately i live in essex so a bit to far to pop over :-)but thanks for the offer.I like the look of your tank raising mod and while im fettling i think i will nick your idea there is not a lot of clearance between carb top and tank bottom so this can only help.Norm carb is fitted directly upright at mo so will also try the slight lean out method. Im going to have a bit of a fettle this weekend so ill post back on monday and let you know how it goes.
Once again thank you both for your input,
Cheers chris.

[Midge]

Disconnect the carb inlet so that you can see the slide, then twist the throttle open and closed quickly to see if the slide is dropping correctly without sticking anywhere. If the cable route is ok, my guess is on the needle being off centre.

[Alan R]

Hi Matey----------if the PAV junk has been removed just check that the little tube coming out of the inlet manifold immediately behind the carb has been blanked-off properly....It sounds like a weak mixture to me............