H1 missfire

[Tartan Triple]

you should be able to tell which cylinder as when it kicks back in, it will smoke a bit more, I am going with carb issue

[Ogri211]

i will get my pal to sit behind and check it out.

[Ogri211]

Thinking about what you are saying Tartan, the first year I had the bike it went OK, but when I rebuilt it I had constant problems with leaks from the float chambers, so I replaced the needle valves with viton ones, im thinking the symptoms I have could be caused by petrol starvation and this could be related to float heights, I set them up using takeaway container with the carb with the float bowl removed on stilts, any carb advice would be helpful as I have exhausted the electrical side by checking and replacing just about everything.

[Tartan Triple]

I have always just turned the carb upside down and with a steel rule, set the floats to 22-24mm

[Ogri211]

I took them apart again today if I set the floats below about 27 mm fuel just pisses out I have checked and the floats aren't punctured but if I try and set them to spec the fuel level is too high I changed the float needles to viton ones a couple of years ago as I had constant problems with leaking fuel. I have also checked the overflow pipes and they are fine so something is not right.

[Tartan Triple]

I took them apart again today if I set the floats below about 27 mm fuel just pisses out I have checked and the floats aren't punctured but if I try and set them to spec the fuel level is too high I changed the float needles to viton ones a couple of years ago as I had constant problems with leaking fuel. I have also checked the overflow pipes and they are fine so something is not right.

needle valves then, get original from motocarb and set the floats to the right height and should be fine

[Ogri211]

will do

[Wolfie]

Aye lad, if the Viton tipped valves are a slightly different length then the upside down / ruler method isn't going to work, your carb on stilts method should still be good though.

[Ogri211]

Another thing I have been reading about is the needles and needle jets in the carbs, when I bought the bike the previous owner said he had fitted Keyster carb kits, which I have since read about are not to the highest standard, also I have heard that the original 5DJ19 needles are not available anymore, but some people where saying that they may run with 5 EJ 13 needles , what would anyone recommend that I fit to my carbs because I will need to try and eliminate this as a potential problem as well. Is there a kit that I can fit that has been proven to be reliable.

[downpipe3]

Another thing I have been reading about is the needles and needle jets in the carbs, when I bought the bike the previous owner said he had fitted Keyster carb kits, which I have since read about are not to the highest standard, also I have heard that the original 5DJ19 needles are not available anymore, but some people where saying that they may run with 5 EJ 13 needles , what would anyone recommend that I fit to my carbs because I will need to try and eliminate this as a potential problem as well. Is there a kit that I can fit that has been proven to be reliable.

KEYSTAR ARE ONLY GOOD FOR THE BIN MATE GET INTOUCH WITH STEVE AT MOTOCARB AND FIT GENUINE MIKUNI

[Ogri211]

Ive got a couple of genuine needles from Tangoman, and Ive got genuine pilot and main jets from Steve, when I get home I will ultrasonic the carbs fit the new parts and set up the float heights, hopefully this will sort my cutting out, I also think if I sort this I may invest in a set of Ivans jets for the spring , a couple of boys on my other post recommended them and I have read quite a few posts about them all seems to be good stuff.

[Ogri211]

Seems to be fixed now, with top advice from the forum and especially Tango Man, he was correct with saying that the problem was most likely float heights and related to me using non standard needle valves. I stripped the carbs and done them in my ultra sonic, rebuilt them with needles supplied by Tango Man and also discovered I had the wrong needle jets, 172s fitted rather than 194s, again correct parts supplied by tango man, fitted new cruisin image floats and a set of standard needle valve that Tango man sent me , set the floats to 24mm and no leaks, reassembled carbs with correct jets from Motocarb. Took the bike out and rattled it no missing, just a small amount of pre ignition at the top end which is probably down to fine tuning or main jet size but all in all delighted with the result. Thanks for all the help and especially to Tango Man.Next stop I think a set of Ivans jets now the problem has been solved..