I brought a 604 DS (rotax) to give it a bit of TLC which had a badly welded r30 front pipe (Joins at rear of engine) and some carbon fibre end can (looks like off an R6?) i couldn't save the front of the pipe so untill i can fund welding up the r30 front pipe i have put on the standard thinner dia front pipe (which joins at the front of the engine) and race ccm remus end can (without baffle ) with the Dellorto PHM 40 (no Accel pump)
first start was ok choke on seems rather rich with restricted air flow untill reved so slight throttle required and idle (off choke) also seems restricted air flow, first ride and she pulls well...... up to 3/4 and full throttle was flooding so i swapped out the 205 main jet for a 185 and now still pulls well and full throttle runs spot on but 3/4 still bogs n then pops and bangs and flames when throttle off off but runs better with the choke on at 3/4 throttle so i assume needles rich,
The link i used is...
http://advrider.com/index.php?threads/r ... or.635497/
so my set up atm is
Dellorto PHM40 (No accelerator Pump)
k35 Main Needle 2nd clip from pointy end :)
185 main jet
268DR Main Atomiser
CCM surge washer (with holes and cut out for air jet)
300 Float set to 18mm (as it says 17.5-18.5 in manual but will try 17mm)
B40 Idle Atomiser
32 Idle Jet
55 Starting jet/choke jet
clean light brown centre with slight black outer ring NGK Iridium plug (have ordered new brisk plug aswell)
no compression tester but compression seems good (untill decomp used) so i assume timing is also good, i will adjust tappets to 4tho in and 6tho ex at TDC to check the cam belt i installed :/
Right so i am going to follow Montys recommendations which is...
Gasket set: 52544-77
Needle jet/atomiser: 268DR
Float needle valve: for the 604 is a 300.
Main jet: 175 standard for 604, 185 for a 636? Fit 185 for aftermarket cans on a 604.
Idle/Pilot jet: The CCM factory said that they fitted a 32 idle jet purely to get it through emissions, but to get the thing to run right it needs a 40 idle jet.
Choke jet: If it is a 60 put a 47 in. It will start and idle on choke then whilst you put your gear on etc., something they never do standard.
Settings on the Rotax carb are absolutely critical especially the float height which should be 17mm.
Put the aftermarket can on, up jet to 185 main and drill the airbox, try needle second richest, one groove up from the pointy end, set idle mix 1.5 - 2.5 turns out
On a 40 pilot 2.5 turns out should be enough, but if 3.5 works then its all good!
Be sure that the slide is sitting home (closed) with slack in the cable before adjusting the idle speed.
If the slide is raised on the cable to achieve tickover the idle circuit is bypassed, this will make it a pig to start and you will never get the idle mixture correct.
Worth checking the throttle cable for free play when the idle screw is wound all the way out.
1. Set idle slightly high (so it wont stall, with bike fully warmed up)
2. Wind mixture screw in till engine starts to hunt/ go fluffy
3. Wind screw out, counting the half turns as you go, till engine again starts to hunt/go fluffy.
4. Set the screw half way, i.e. if you counted 3 complete turns out (between fluffy in and fluffy out) screw in 1½ turns, that then will be your optimum setting for the mixture screw.
.....so i will buy....
k32 Main needle (leaner taper)
new 300 float (dont know if the rubber has perished)
40 Idle Jet (worth trying any more? would the B40 atomizer restrict it?)
they do not do a 47 choke jet on dellorto? they do 45 and 40? if i go lower size does that go leaner with the mix if so i may try 45 and go from there?
but my main question which i cant find any info on is the accelerator pump, mine currently does not have one and is blanked over but i think i found them... (link below) and was wondering if it is worth drilling and tapping and installing the accel pump like the race carbs for 400 quid if so any one done it yet is it better??? and what jets/atomizers are best or is it one size? so any help is good help regarding extra possible jet/needle sizes to try or even ways for me to check what spec this bike is (besides my seat dyno ), is there a way to check from the cylinder if its a 604cc or any ways to tell if the cam has been modded, above sprocket says 640707 (where is the engine number on these bikes?).
https://moto-renzo.biz/en/Dellorto-Carb ... --PHM.html
Thank you everyone
I'll make things simple, fit a 175 main jet, 185's only for race can and open airbox.
I dont think you can fit a accelerator pump to a non pumped carb, internal drillings are not there nor the correct slide,