Bikesure_adrianflux

Ho Hum .......new pilot jets are not the correct size

jerry

jerry

Old Git
Joined
May 12, 2006
Messages
3,257
Location
Cricklade
Bike
Multiple Monsters
got some new pilot jets for my 750ss


The old pilot jets are very worn and run a bit rich they were 40 which is normal for M750 and 750ss ,, looking at the supposedly new 40 ones i reckon they are marked incorrectly and looking at them with a old fashioned microscope its clear they are much smaller than the old 40s i took out ????????? cant actually measure them but the may be 37.5 ??? or less ????

when they are in the bike does not idle and runs really lean until over 3k revs also the bike is very very lean and the plugs come out white or completely clean

i have put the old worn 40 pilot jets back in the bike and it starts and runs fine runs but is a little rich at idle and up to 3k revs , the plugs get sooty thats why i want new pilots .. the supplier is saying they are 40s but i doubt it or they are chinky copies ????hmmm
 
Very hard to buy genuine stuff these days unless you go to the main dealer. I had fitted a new set of wheel bearings to my "new" 900 wheels only to notice that when I took them to have new tyres fitted one of the outside edges had gone rusty - never seen a new bearing go rusty before after a month in a dry garage!
 
I've got myself a chinese made play bike (GPX TSE250R) I was sorting the carb a bit which is a keihin clone.
The jets are all over the place size wise, I stepped up a size and got a not as rich as expected result.
Someone did put a set of their jets in for testing and the real fuel rates were OK for some but off for others, higher or lower by a size!!
I had to dig out an old baccy box of very old jets from my enduro days to end up with it right.
 
im helping my mate dave do the carbs on his Fazer 600 ,, the 4 float bowl gaskets are a disaster we put the 4 carbs back together and the float bowl gaskets all leak like a sieve .

We have had Keyster kit gaskets from NRP,, gaskets from Wemoto and some others of Fleabay all the same they are not made of correct VITON material or they are not the correct thickness to seal way too thin by 0.4mm ????!!!!!!! ,,, we have the old ones that are perished and they are better than all the replacements

,, we have now ordered genuine YAMAHA ones at £15.42 each that £62 for the gaskets ,, but yamaha cant supply for 6 weeks ,,,
 
Just bought x3 lines off Venhill - £175 if that makes you feel any better

Brake lines not lines of white powder either!
 
Spoke with gentleman at NRP he tells me that the genuine slow /pilot jets in 40 size for 750cc are unobtanium for mikuni BDST 38 carb he has genuine mikuni 42.5 for the 900 models ,, he says most of the jets out there even from some good suppliers are Hinky chinese ones , thats the same experience i am having with my mate Daves yamaha fazer 600 float bowl gaskets ....

he has mentioned that my rich low speed running may not be the worn jets,,,, but could be the choke plungers???? or now the old jets will have to go back in ...
 
This is part of the reason I went with brand new carbs as rebuilding my old ones plus the cost of a Dynojet kit was just not worth it compared to new flatslides.
 
OK what size is the Viton O Ring for the push in jet on BDST38 ???? i need to order some i believe from my measurments of old ones they are OD 6.4mm ID 4mm 1.2 thick ???? Thats what Frank MX says
 
Last edited:
You must log in or register to reply here.
Back
Top