SATANSAM Posted January 25, 2021 Author Posted January 25, 2021 Na, mixture screw o'rings in it's place...Measured all of them and they all measure the same....I'm totally lost...Can't be anything electric, CDI tested OK, Alternator OK, regulator OK, couls OK, caps OK, sparx OK, Valve clearance OK, no air leaks, damn thing is asking to be sold. Quote
SATANSAM Posted January 28, 2021 Author Posted January 28, 2021 Hi folx, Do you think a low float height could cause this? Excesive petrol in the pilot circuit...the the float vallve and oring are new (aftermarket but new). The circuit is clean as I stuffed it with intake cleaner, compressed air.... I'm using an external plastic tank ait a transparent fuel filter between (you can see fuel getting in perfectly) for this and blocked the vacuum pipe from carbs with a screw ok. As you can see on. the carb balancer, cylinder 3 does not vacuum as much as the rest, and if I get all the same bike goes up to 4000rpm or so...Does this suggest anything to anybody? Man....This is really driving me nuts. Quote
Blubber Posted January 28, 2021 Posted January 28, 2021 I have -recently- not gone through your previous attempts to fix this but here are a few pointers: Compression ok? Valve clearance ok? Valve lift / caml obe ok? Have you checked the carb top for cracks or leaks? / is the o-ring installed ( if applicable )? Is the carb diaphragm pinched, ruptures or even a pinhole->easiliy overlooked If you connect vacuumgage 3 on 4.. do you get the same results? Have you bench sync the carbs prior to this result? HTH to keep you sane 1 Quote
SATANSAM Posted January 28, 2021 Author Posted January 28, 2021 Hi B, The only thing that is "weird" is the compression (all 90PSI except the 3rd cylinder that reads bout 110PSI)...But loox like it's the compression tester as the other bike reads very underneath too. Compression ok? NO Valve clearance ok? YES Valve lift / caml obe ok? Sorry but What does this mean? The valve lift ok... Have you checked the carb top for cracks or leaks? / is the o-ring installed ( if applicable )? NO LIEAKS OR CRACKS Is the carb diaphragm pinched, ruptures or even a pinhole->easiliy overlooked - OK, BUT I'LL PUT A TORCH BEHIND IN THE DARK. If you connect vacuumgage 3 on 4.. do you get the same results? - SAME READINGS ON 3 AND 4 (3 POOR VACUUM) Have you bench sync the carbs prior to this result? YES So, I'm stripping them out AGAIN, see float height, spray the needle valve, see the diaphragm, bench sync... It's all so weird, the bike started failing when I changed the tank, it rusted and carbs got full of rust (1 cylinder off sometimes). Hamered the carb and cylinder in again...Took them out, cleaned them, on again, all cylinders ok BUT REVED. Now other carbs restored on the spot and still over reved... Quote
Blubber Posted January 28, 2021 Posted January 28, 2021 2 hours ago, SATANSAM said: Hi B, The only thing that is "weird" is the compression (all 90PSI except the 3rd cylinder that reads bout 110PSI)...But loox like it's the compression tester as the other bike reads very underneath too. Compression ok? NO Valve clearance ok? YES Valve lift / caml obe ok? Sorry but What does this mean? The valve lift ok... Have you checked the carb top for cracks or leaks? / is the o-ring installed ( if applicable )? NO LIEAKS OR CRACKS Is the carb diaphragm pinched, ruptures or even a pinhole->easiliy overlooked - OK, BUT I'LL PUT A TORCH BEHIND IN THE DARK. If you connect vacuumgage 3 on 4.. do you get the same results? - SAME READINGS ON 3 AND 4 (3 POOR VACUUM) Have you bench sync the carbs prior to this result? YES It should have read "Valve lift / cam lobes ok" . A worn camshaft lobe or camshaft profile will result in a weird running bike because the valve will open less. Happy hunting 1 Quote
TonyGee Posted January 28, 2021 Posted January 28, 2021 i wouldn't be happy with the compression test figures !!!! anything below 100psi is not good !!! they sould be done with a warm engine so it might be worth letting it rev for a while and re'doing the test and with full open throttle. 1 Quote
SATANSAM Posted January 28, 2021 Author Posted January 28, 2021 I'll do a propper compression test tomorrow...But this afternoon I put my hand on the air filter intake, only fingers (didn't cover it completely) the bike lowered revs of course but without stalling, then revs up again then down, up, down, up, down, up, down, mathematically....What the heck? I directly thought abuut electric...More or less at the same time of the super dirty carbs making the cylinder fail, 2 of the 3 alternator cables were melted by hanging on the motor...I re-soldered them OK, but I'm thinking that maybe that issue maybe fried the rectifier...Things are coming out and now I'm sure it's not the carbs, followed the manual strictly, like a monkey in a circus. Thanx guys, U R the best help. Quote
Pudzrx Posted January 28, 2021 Posted January 28, 2021 Since you have been taking off and swapping the carbs , have you balanced the carbs in pairs then both pairs together ? ( in sets ) Tbh , I would have paid a motorcycle mechanic to have a look at it by now , I bet its something really simple. 1 Quote
Captain Chaos Posted January 29, 2021 Posted January 29, 2021 8 hours ago, SATANSAM said: revs up again then down, up, down, up, down, up, down, mathematically.... Sounds like compression on one or more cilinders is low 1 Quote
Captain Chaos Posted January 29, 2021 Posted January 29, 2021 6 hours ago, Pudzrx said: Tbh , I would have paid a motorcycle mechanic to have a look at it by now , This ^^^ 1 Quote
SATANSAM Posted January 29, 2021 Author Posted January 29, 2021 You can't trust mechanics around here, not one of them....I think I must leave the bike alone for some time. Thanx Quote
SATANSAM Posted January 29, 2021 Author Posted January 29, 2021 18 hours ago, TonyGee said: i wouldn't be happy with the compression test figures !!!! anything below 100psi is not good !!! they sould be done with a warm engine so it might be worth letting it rev for a while and re'doing the test and with full open throttle. You R gonna kill me but yep, motor warm and here are the resoults: 4 = 140Psi 3 = 127psi 2 = 120Psi 1 =140Psi Well at least I know it hasn't got to do with the motor, well, I think hahaha Quote
TonyGee Posted January 29, 2021 Posted January 29, 2021 they are much better readings. did you do them with a warm engine ? Quote
SATANSAM Posted January 29, 2021 Author Posted January 29, 2021 3 minutes ago, TonyGee said: they are much better readings. did you do them with a warm engine ? Yes I did, just as you said, I've got a lot to learn here m8 Quote
Captain Chaos Posted January 29, 2021 Posted January 29, 2021 4 hours ago, SATANSAM said: You can't trust mechanics around here, not one of them....I think I must leave the bike alone for some time. Thanx I've been a motorcycle mechanic for 20 years. You pay the trip to Spain and back and I'll fix your bike. Quote
Swiss Toni Posted January 29, 2021 Posted January 29, 2021 Just a small point, as you seem to be getting there ... when you’re balancing your carbs with the gauges, the #3 carb is usually the ‘datum’, ie, non-adjustable. Set the other 3’s vacuum to this one. Might be a different set-up on yours, but worth checking. 3 Quote
TonyGee Posted January 29, 2021 Posted January 29, 2021 1 hour ago, Captain Chaos said: I've been a motorcycle mechanic for 20 years. You pay the trip to Spain and back and I'll fix your bike. lol yeah same here Quote
SATANSAM Posted January 29, 2021 Author Posted January 29, 2021 2 hours ago, Swiss Toni said: Just a small point, as you seem to be getting there ... when you’re balancing your carbs with the gauges, the #3 carb is usually the ‘datum’, ie, non-adjustable. Set the other 3’s vacuum to this one. Might be a different set-up on yours, but worth checking. Thanx Swiss, yes I'm actually doing that, all butterflies closed, use the idle screw to open or close the number 3, then sync.carb 2 to 3 (reference) , then 1 to 2 and then the 4....the thing is that to be balanced the bike has to be at bout 3000 or more rpm... Quote
Swiss Toni Posted January 29, 2021 Posted January 29, 2021 I’m almost sure all the carbs are synced to the #3. It’s a long time since I’ve seen the manual, so I may well be wrong! Quote
TonyGee Posted January 29, 2021 Posted January 29, 2021 (edited) not sure about your bike Sam but generally you do 1 to 2 then 3 to 4 and then 1and2 to 3and4 Edited January 29, 2021 by TonyGee Quote
Pudzrx Posted January 30, 2021 Posted January 30, 2021 17 hours ago, TonyGee said: not sure about your bike Sam but generally you do 1 to 2 then 3 to 4 and then 1and2 to 3and4 Thats what I said. Can't be arsed to go back over the thread again , but have either set of carbs been PROPERLY ultrasonically cleaned ? Puddy Quote
SATANSAM Posted January 31, 2021 Author Posted January 31, 2021 22 hours ago, Pudzrx said: Thats what I said. Can't be arsed to go back over the thread again , but have either set of carbs been PROPERLY ultrasonically cleaned ? Puddy No they haven't Pud, Quote
SATANSAM Posted January 31, 2021 Author Posted January 31, 2021 On 1/29/2021 at 5:13 PM, Swiss Toni said: I’m almost sure all the carbs are synced to the #3. It’s a long time since I’ve seen the manual, so I may well be wrong! Yes U R right Swiss, according to the manual all carbs are synced to the reference carb 3 yep Quote
Swiss Toni Posted January 31, 2021 Posted January 31, 2021 2 hours ago, SATANSAM said: Yes U R right Swiss, according to the manual all carbs are synced to the reference carb 3 yep There you go! The old mind's still working then! (Well, maybe parts of it)! 1 Quote
SATANSAM Posted February 1, 2021 Author Posted February 1, 2021 I took all air filter boots that go to the carbs out and found this crack in the boot that goes to cylinder 3...Stuffet it with gasket silicone to try tomorrow... I don't think that crack would hang the idle this much, but I've already been wrong in most of the things Beer time. Quote
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