mrgsr

iTrader: (15)

Tom ill stick to my TZ's for now till they fix all these issues
my last tz lasted a whole year more than 25litres and was still strong!
all on standard conrod bearing etc, all i would do is just clean the outside.

last race meet it started to create blow by and lean so i replaced the piston/sleev

CraigM

iTrader: (34)

Hey John, I ran 7 or so tanks through my new CRF without encountering any of Tom's problems, and compared to my modified TZ it is much faster. The carby feels pretty solid at the moment but I'll see how it goes under race conditions at the next clubby

CraigM

iTrader: (34)

Does this mean its too lean on the LSN or too rich? mine does this a little, I read Bobby's method but he doesn't explain what he does to get it to return to idle immediately. My engine only runs at 92 deg C (197F) on 16% so i'd expect to have to go leaner

rmdhawaii

iTrader: (4)

When it doesn't return right away, it means something is too lean and you have to richen it up. You may have to play with the needles a bit to find the right balance between the idle & LSN.

At 197F, try leaning your HSN 1 hour at a time. Put in on the track, run it for a few laps, bring it in and check your temp and idle.

TomB

iTrader: (10)

or he has an airleak........the crf though acts lean when it is rich, just lean top and bottom dude, then see if it still does it, if not it's fien, ten re tune top at the track.

rcabj

iTrader: (1)

deleted...sorry wrong posts

rmdhawaii

iTrader: (4)

My experience has been...

If it's bogging (whaaaa whaaaa whaaaa sound), it's too rich. This use to be a really big problem with the original carb, but with the updated carb, it's not that bad. If you stop the car, let it sit for 10 seconds and it bogs really bad or just won't get off the line, you know you have to retune. If it won't get off the line, pumping the throttle may get it going. What's interesting about the CRF, is that even if it's way too rich sitting at idle after warming up, it may not die on you and just bog when you get on the throttle.

If you've been running for 3 minutes or more and it starts to make a fast "ha ha ha ha" sound, the engine is starting to go or is already too lean and it's best to pull it off the track and check the temp. It won't always make this sound if it's going too lean, but it is definitely something to listen for.

When your idle/LSN settings are off and you blip the throttle, if it's too lean, the engine revs will stay up. If it's way too lean, it will start to rev out of control. When adjusting the LSN, make sure that you don't set your LSN too rich or you'll be too rich after being off throttle out on the track, which will slow you down when you get back on throttle and perhaps negatively impact mileage.

Haven't had any air leak problems with the engine itself. If I suspect an air leak or just to rule it out, I usually change the fuel hose. I can get a bit careless with the ends of the header retaining springs.

CraigM

iTrader: (34)

I dont think its an air leak because the idle is very consistent, it just takes a second or so to return to idle. It's not too lean down low because it still blows plenty of smoke after idling for 5 seconds (doesn't really bog), it might be lean on the hsn and rich on the lsn I guess, TBH I need to have more of a play with it, if i cant tune it out I'll look for an air leak

TomB

iTrader: (10)

just to let you know, even with the loose carby issue mine idled fine in the pits. the problem arrised though when the engine got hot and the whole case+ carb expanded.

if i still have issues, i might just install, or at least try to, install the carby from my ninja. i still think the carb retaining nut and bolt system needs to be beefed up personally. i purchased a spare bolt and clamp for the carby, does anyone know how i can drill this out to accomodate a 2.5mm screw or a 3mm screw? (i think a 3mm screw will not fit though) i'm hoping to put a long enough bolt through that will allow a nut to be used on the other end

CraigM

iTrader: (34)

you'd need a drill press man, but looking at the manual the set up doesnt look like a normal carby screw would fit. have you tried putting a spacer between the screw head and the o-ring to give the screw a bit more clearance?

CraigM

iTrader: (34)

OK I figured it out, the idle was set too high. To sort it out I had to turn it down till it stalled, then kept turning it out till it started. It's lower than i usually set my idle but I'm a half a turn leaner than I was on both needles now and it returns back to idle after being gassed. I get a little bit of bog now because the clutch engages before the engine is really spinning but my temps are 105-109 now and the engine performs really well once it gets past the bog from the clutch. So far no sign of the carb problems tomas is having too

TomB

iTrader: (10)

wind the clutch spring in 1/4 to 1/2 a turn man..possibly even 3/4 if it is reeeealy early.

blanks596

iTrader: (20)

Could someone verify whether or not the CRF plugs are similar to the ofna/pico and os plugs? I've noticed that the taper of these plugs look more similar than the NovaRossi plugs.

blanks596

iTrader: (20)

just to answer myself and to help anyone else, the Picco plugs do not seat well in the head of the CRF. The Picco look similar, but head of the cone does not sit flush in the combustion chamber as dose the original CRF plugs.

CraigM

iTrader: (34)

ok so I took my CRF apart and cut the insulator off the carb to replace it and noticed fuel had been leaking through my front bearing, so I believe I found my air leak. The engine has only done 1L, is there any reason this would have happened so early in it's life? Also, how do i replace it? I've heard you have to heat the block to get them out, but I also assume I have to take the crank out and all. Should I put a CRF one in or are there better quality ones around that i'd be better off using?