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Post by midlifecrisisrd on Oct 4, 2019 21:24:25 GMT 1
Had the 3hm1 out for a mile or so
Seem to have the spark issue sorted now but it runs like crap
It's on standard pilots and 2 sizes up on mains as got pipes on it.
Carbs cleaned out including behind balls
Starts without choke and spits wet black sh1t out the pipes
After the mile run you can hold the belly of the pipes without getting burnt
Its 4 stroking I reckon. Thought it was only running on one but both cylinder firing
Not a lot of smoke considering it's so rich but I reckon it ain't burning it hence the black crap
New plugs, new coil
Sounds and feels very flat. Almost not like a 2 stroke
Any ideas?
Steve
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Post by marsbar350 on Oct 4, 2019 21:25:56 GMT 1
check the timing steve an easy one to start with
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Post by midlifecrisisrd on Oct 4, 2019 21:27:25 GMT 1
check the timing steve an easy one to start with It's fixed, can't adjust it 🙁 Steve
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Post by marsbar350 on Oct 4, 2019 21:29:37 GMT 1
carb balance
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Post by midlifecrisisrd on Oct 4, 2019 21:35:23 GMT 1
carb balance They are balanced as jap spec linked carbs so slides balanced by an adjuster screw Choke doesn't affect it. I've even tried another choke plunger in case it was stuck on The pain in the ads is bike specific stator, cdi and carbs so can't swap out to test 🙄 Steve
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Post by midlifecrisisrd on Oct 4, 2019 21:36:19 GMT 1
I wonder if the slides fit in the wrong way round 🤔
Steve
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Post by ianboom on Oct 4, 2019 21:57:17 GMT 1
Air filter blocked/damaged? Carb slide stuck.
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Post by midlifecrisisrd on Oct 4, 2019 22:11:12 GMT 1
Air filter blocked/damaged? Carb slide stuck. New genuine filter in it The carb slides are activated by an arm so not just a spring return One cable pulls open, one pulls closed Steve
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Post by ianboom on Oct 4, 2019 22:14:50 GMT 1
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Post by midlifecrisisrd on Oct 4, 2019 22:45:13 GMT 1
Link not working but the name made me laugh 😂 Steve
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Post by 137d on Oct 4, 2019 22:52:18 GMT 1
Link not working but the name made me laugh 😂 Steve Plug gaps? sounds like too much fuel and not enough firing.
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Post by midlifecrisisrd on Oct 4, 2019 22:58:45 GMT 1
Link not working but the name made me laugh 😂 Steve Plug gaps? sounds like too much fuel and not enough firing. I'm on the second set of new plugs I'm afraid. New caps too. When I stripped it the crank cases were full of black fuel and it had not really been used since the mad Jap had done his bit so may have a historic problem Time will tell Steve
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Post by muttsnuts on Oct 5, 2019 8:36:01 GMT 1
set back to stock carb jets, it sounds like its way too rich, at least if its on stock jetting you have half a chance of knowing if its something else, you don't always have to up jet with after market exhausts, sometimes I've gone down on jets !
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Post by midlifecrisisrd on Oct 5, 2019 8:41:24 GMT 1
set back to stock carb jets, it sounds like its way too rich, at least if its on stock jetting you have half a chance of knowing if its something else, you don't always have to up jet with after market exhausts, sometimes I've gone down on jets ! Cheers Dave, that was my plan. I'll be on to you for 1 size smaller pilots, standard pilots and standard mains I don't trust the original ones have not been drilled as it had standard jets but pods and pipes Is there any chance it's pipe mismatch? They are tzr race pipes (I've checked they are clear) so obviously not for this engine It sounds it's best at idle. Doesn't bog or die on large throttle openings Steve
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Post by muttsnuts on Oct 5, 2019 8:51:58 GMT 1
yeah, could very well be the pipes are completely wrong for the bike, but starting back at stock jet settings a good place to be, should have the jets on stock if required, just let me know
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Post by midlifecrisisrd on Oct 5, 2019 9:52:07 GMT 1
yeah, could very well be the pipes are completely wrong for the bike, but starting back at stock jet settings a good place to be, should have the jets on stock if required, just let me know Cheers Dave, will do. Just done 10 mile round trip to mot test and it's looking like carbs At idle left cylinder is in and out. Right is fine It started and drove off immediately without choke It won't go over 5k. Anything over 4 is a struggle Its like a muffled gattling gun when riding. It only clears while loaded up on 3/4 throttle between 3 and 4k The fact it clears at all says carbs to me I'll check the standard jet sizes then let you know what I'm after Steve
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Post by steeley on Oct 5, 2019 12:52:47 GMT 1
Hi, my mates 250 wolf / naked vj21 wouldn't run very well and was crap mpg wise. In the end I built a spare pair of carb bodies up with new jets ect and gave him a hand fitting them . When he tried the bike out he said it was like riding a different bike. The jets in the old carbs had been improved by previous owner / butchered so the sizes / numbers on them were worthless.
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Post by hoist1 on Oct 6, 2019 1:05:45 GMT 1
Has previous owner adjusted or shimmed the carb needles? Have found this can stifle things.
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Post by midlifecrisisrd on Oct 6, 2019 8:38:47 GMT 1
Has previous owner adjusted or shimmed the carb needles? Have found this can stifle things. I'll have to check that Cheers Steve
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Post by rich on Oct 6, 2019 10:58:26 GMT 1
Iffy CDI causing a weak spark, or maybe a stator? Bit of a faff but could you try one off another bike? That age should be the same as the F2 setup.
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Post by midlifecrisisrd on Oct 6, 2019 13:22:16 GMT 1
Iffy CDI causing a weak spark, or maybe a stator? Bit of a faff but could you try one off another bike? That age should be the same as the F2 setup. It's something I'll be checking but the problem is the cdi is a combined cdi/pv controller specific to the 3hm1. The stator is too If all else fails my next build will have an ignitech so I can always buy it early and temporarily connect it up Steve
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Post by 17again on Oct 6, 2019 13:43:44 GMT 1
i would do what dave says and go back to standard jets.
then try a different set of pipes your spare allspeeds maybe.
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Post by midlifecrisisrd on Oct 6, 2019 14:00:38 GMT 1
i would do what dave says and go back to standard jets. then try a different set of pipes your spare allspeeds maybe. That's the plan mate Ordered 22.5/150 from Dave I'm going to try putting the old coil back on first Steve
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Post by midlifecrisisrd on Oct 9, 2019 19:31:33 GMT 1
Little update
I've got the jets from mutts but thought I'd have a mess about first
I'd fitted a new pattern coil from norbo as the original had the HT leads jointed to some transparent red leads and some black rubber plug caps
I fitted new ngk burgundy resistor caps as that's what I usually use
I took the new coil off and fitted the old set up and removed the carb rubbers to make it lean
As soon as I switched the ignition on it backfired on the left cylinder so obviously soaking with fuel
Kicked it and it started on the right but dead on the left other than leaking black fuel out the manifold
Changed the lh plug and it fired straight up, nice and responsive and crackling nicely
It's a bit boggy pulling away now but airbox not connected
Think I'll wait now for a v5 so I can give it a run and clear it out
Steve
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Post by 4l04ever on Oct 9, 2019 21:18:52 GMT 1
Check for twisted crank , as backfire could be ignition timing issue. Mark TDC for left and TDC for right cylinder on the stator to a fixed reference point on the engine, then measure both ways round the flywheel and should be the same measurement both ways if it is bang on 180 degrees as it should be.
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Post by midlifecrisisrd on Oct 9, 2019 21:32:19 GMT 1
Check for twisted crank , as backfire could be ignition timing issue. Mark TDC for left and TDC for right cylinder on the stator to a fixed reference point on the engine, then measure both ways round the flywheel and should be the same measurement both ways if it is bang on 180 degrees as it should be. The backfire was actually without doing anything When the ignition is switched off there must be charge left in the cdi. When the ignition is switched back on it discharges and ignites the wet fuel in the cylinder Well that's what I'm thinking lol Fingers crossed Steve
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Post by Gunny on Oct 10, 2019 7:08:27 GMT 1
Just done 10 mile round trip to mot test and it's looking like carbs Steve Must be the most miles you`ve done in years
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Post by midlifecrisisrd on Oct 10, 2019 7:46:54 GMT 1
Just done 10 mile round trip to mot test and it's looking like carbs Steve Must be the most miles you`ve done in years F*ck off 🤣🤣🤣 I did 30 last year 😬 Steve
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Post by madmick on Oct 10, 2019 9:12:41 GMT 1
Check for twisted crank , as backfire could be ignition timing issue. Mark TDC for left and TDC for right cylinder on the stator to a fixed reference point on the engine, then measure both ways round the flywheel and should be the same measurement both ways if it is bang on 180 degrees as it should be. The backfire was actually without doing anything When the ignition is switched off there must be charge left in the cdi. When the ignition is switched back on it discharges and ignites the wet fuel in the cylinder Well that's what I'm thinking lol Fingers crossed Steve I think your spot on Steve. I’ve come across it a lot when diagnosing problems before. M.M.
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