Siebenrock 1000cc Jetting advice needed

[(RIP) maverick]

I have the 1000cc Siebenrock kit fitted on my R80 g/s and still fitted with the stock 32mm bings.

When I open the throttle 70% onwards it seems to starve from fuel and splutters and miss. The jets was severely blocked standing for a couple of years and then another two years with me with the odd starting now and again. I have done a sonic clean on the one carb making it slightly better but think it is time to replace the jets.

Now do I go with standard jets (and what is their size?) or is there any benefit in increasing them slightly?

 

[Rob Farmer]

I'd stay with the standard size and then spend £30 on a dyno run to see just what's happening. The temptation is to go for larger jets but the reality is that the originals are probably fine. I'd be more inclined to think you still have an issue with gummed up carbs.

 

[Garry H]

Kept mine on standard jetting
135 main, needle curclip in the middle ( 3 )
But found it a bit lean off the bottom so i drilled the pilot out to a 48
Best buy a 48 unless you have the proper kit to drill it
Mine runs great... But don't forget you will also need to set evrything else up correctly

 

[cookie]

the one i converted ran fine on standard settings. AFAIK it still does.

 

[(RIP) maverick]

Thanks for the advise and suggestions chaps

 

[mikyh]

Standard, till I replaced

the collector box with an after market 2 to 1 tubes. I had to go for 145 to stop the detonation when applying heavy throttle.
M

 

[chasbmw]

Check the float height. It's probably too low

 

[Beemerboff]

#1 on the float levels.

But check the diaphragm for small holes too

You could also try a stiff dose of fuel injection cleaner.
Yamaha dealers have a Yam branded one which seems to work well, and it is also a fuel stabiliser so it helps stop similar happenings, if you bike gets occasional use.

 

[cookie]

the one i converted ran fine on standard settings. AFAIK it still does.

i was wrong on that. i've now been told it's on 150 main jets, which it was before i fitted the big bore kit.