Intermittent problem?

[F5 Dave]

As above, but if the plug fouls up then it is likely the carb emulsion tube worn oval, do a search, been covered here a few times.

Plug may need replacing if fouled, sometimes they don't recover even if they do spark in air.

[erik]

Check the chokes are all closing properly.

[FROSTY:Me]

As above, but if the plug fouls up then it is likely the carb emulsion tube worn oval, do a search, been covered here a few times.

Plug may need replacing if fouled, sometimes they don't recover even if they do spark in air.

What he says.--sorry dude thats what I meant when I said check the needle

[Pixie]

hi.
hoping someone out there with more clues than me has some good ideas about this.
Bike is only running on three cylinders. But not all the time, sometimes it runs on four like it should.
Low mileage rf900. Tonight i went to the nic smith thing, started off on three, about 2km up the road it smoothed out, power on beautifully and ran great all the way there. Coming home again,,,,,,3 all the way running like a pig.

the sparkplugs are fairly new and when swapped around makes no difference.

checked for spark and there seemed to be plenty.

swapped coils around but made no difference. So coils and ht leads are ok?

pulled out carburettors and stripped the offending one loking for blockages or wear........all seems good.

Someone suggested valve problems of some sort.......but surely this would be a constant state.

could it be an ht lead with a fault in the wire?

always same cylinder...........no 3.

any ideas/advice much appreciated

My brother's RF had these exact symptoms.
It turned our to be a blocked filter gauze in the carb on the offending cylinder.
Each carb has a small gauze disc in the fuel pathway to the float bowl.
To access it you need to remove the carb assembly,take off the float bowl,the float and if I remember correctly unscrew the needle valve seat.
In the case of my brother's bike it was a outer cylinder and the blockage was some lint like fibrous material.

[blossomsowner]

thanks for all the ideas and help.
got back from holiday yesterday and had time to play around and put it back together.

i stripped and cleaned and reassembled carbs, got some new ht lead and replaced all leads, made sure all caps and leads very secure.........and a new set of plugs.

Runs pretty good now.........did about 100km last night with no signs of any problems, running on 4 cylinders sweet as.

[MSTRS:Me]

Good stuff.
Hope it stays that way.

Problem is...because you 'fixed' or played with a variety of things, you now don't know which one was the problem. Or even if it was one of those things. Being intermittent, it may play up again.

[Wheeliemonsta]

hi.
hoping someone out there with more clues than me has some good ideas about this.
Bike is only running on three cylinders. But not all the time, sometimes it runs on four like it should.
Low mileage rf900. Tonight i went to the nic smith thing, started off on three, about 2km up the road it smoothed out, power on beautifully and ran great all the way there. Coming home again,,,,,,3 all the way running like a pig.

the sparkplugs are fairly new and when swapped around makes no difference.

checked for spark and there seemed to be plenty.

swapped coils around but made no difference. So coils and ht leads are ok?

pulled out carburettors and stripped the offending one loking for blockages or wear........all seems good.

Someone suggested valve problems of some sort.......but surely this would be a constant state.

could it be an ht lead with a fault in the wire?

always same cylinder...........no 3.

any ideas/advice much appreciated

Gidday,
How many K's is low - RF's (in fact bloody near all Suzuki's fitted with the CVK carbs are prone to this) are well known for radically wearing jet needles, needle jets & emulsion tubes in the carbs in what can seem to be impossibly short periods of times... There was a fault in the surface treatment of the jet needles on the first model RF's but it's my understanding that the bulk of these where replaced as a F.D.M at the bikes first service...

If your bike is an import it may well have missed the boat in as far as the F.D.M campaign went...

I would suggest going through the basics on your bike first to completely eliminate these items from the suspect list...

Then dive back into the carbs - I'm quietly confident this is where you will find the problem, it won't be a cheap fix unfortionately, needle jets run to around $30 ~ 45 each, jet needles $80 ~ 120 each, emulsion tubes $45 ~ 60 each & vacume valve assy's (slides) $300 ~ 400 each retail, if you have a mate in the trade now might be the time to call in a favour as short of the vacume valve assy's you'll need four of each - the vacume valve assy's can be replaced individually...

You may also want to try track down a fellow RF owner & see if you can perloin there crbs for a week or two to confirm the suggested above

Let me know how you go I'd be very interested

Cheers