Float height

[rok-the-boat]

My 1993 DR250 was ticking over a little rough. Adjusting the pilot screw made no difference at all.

I checked the carb, cleaned it out, and discovered the float height was 10mm instead of the 14.2mm in the manual. Once adjusted it ran better - had to bend the tab quite a bit - it looked right as the floats were then level - but then I ran into fuel starvation problems due to a sticking float needle - it didn't seem to open/move enough, have enough free play to open properly. I have now adjusted it to about 12mm and so far so good. (When adjusting you have to press down on the float-stay to simulate the bottom of the carb being fixed on - it can make quite a difference to height).

My needle looks worn but the carb does not overflow. I asked Suzuki how much for a new one and it was over $80!!!! + GST. I now like my worn needle.

As far as I can tell, float height effects:
1 Smooth opening of the float needle
2 Tickover (level of fuel in the carb and ease of emulsification up the intermediate and main jets)
3 What else? Anyone know?

[scumdog]

Get another needle and seat, you've only fixed half your problem and you'll save fuel too and have a more ridable bike too.

[F5 Dave]

ok the bush method is to drill the float jet out a size, from the inside. Then drop a small ball bearing into the hole & give it a decent tap with a centrepunch to make the seat even. This should help the jet seal on an undamaged part of the needle.

This will however change the float level as the needle goes further in so you will have to bend the centre tang in a bit to correct it.

Obviously check the carb doesn't flood afterward, if so repeat with more care.