CBR250R heart transplant, now won't run

[kiwi-on-wheels]

Heya guys, just done a heart transplant my mc17
Took everything from the transplant bike, wiring loom, cdi unit, coils, carbs, everything.

Working in old frame, swap it to my frame, no go.
Tried multiple combinations of spark unit,sensor unit, rectifier,no luck. Turns over doesnt fire.

Stuck my original loom back in, using the original cdi and rectifier etc, turns over, has a couple of attempts at firing at full throttle, then nothing.

Going to stick my original carbs back on and give it another crack,but i'm stumped.

All the coils test out right, both cdi units work, both ignitor sensors work, everything from both bikes test out perfectly but it just wont fire.

Both bikes ran fine (well, my original with the blown hg ran a bit naff) before the swap, which is why im so stumped

Anyone got a suggestion? At the moment i'm tearing my hair out, I just want to go for a ride, all this amazing weather the last 4 weeks (well,apart from the last few days) i'm itching to get out on the bike

Any suggestions would be greatly appreciated

[nzspokes]

Turn the kill switch to On.



Bahahahahahaha


Manually check for spark. If you have it put a little gas in each plug hole and spin it over. If it fires you know its carbs.

[kiwi-on-wheels]

:-P

Its funny you should say that, overlooked it once or twice in the diagnosing.

Found it though, felt like a dick, tried again but nope still no luck :-(

It'll ignite engine start happily with the carbs off, but both motors were running happily with the carbs on, I literally frame swapped the motor so I dont know why the same carbs wouldnt still work on the same motor...

Guess i'm stripping carbs again yay

[kiwi-on-wheels]

stripped, cleaned, rebuilt carbs
it now pours petrol out the overflow, floods cylinder 3 and still wont fire.

put it away for the day before i break something LOL

good thing i have a second set of carbs sitting here, might take a crack at those ones tomorrow, re-set mix screws, clean out the jets and balance, then they should be good to go.

any other suggestions? this bike is doing my head in, i just want to riiiiide....

[nzspokes]

stripped, cleaned, rebuilt carbs
it now pours petrol out the overflow, floods cylinder 3 and still wont fire.

put it away for the day before i break something LOL

good thing i have a second set of carbs sitting here, might take a crack at those ones tomorrow, re-set mix screws, clean out the jets and balance, then they should be good to go.

any other suggestions? this bike is doing my head in, i just want to riiiiide....

Float valve worn or contaminated.

[tigertim20]

are you trying to start it while is on its stand . . . ?

[kiwi-on-wheels]

Will have another look at the float valves cheers.

And yeah, on side stand. Has no center stand.

Worth proping it up so its level? It doesnt have a level cutout, or a side stand cutout... Its too old LOL

[actungbaby]

Heya guys, just done a heart transplant my mc17
Took everything from the transplant bike, wiring loom, cdi unit, coils, carbs, everything.

Working in old frame, swap it to my frame, no go.
Tried multiple combinations of spark unit,sensor unit, rectifier,no luck. Turns over doesnt fire.

Stuck my original loom back in, using the original cdi and rectifier etc, turns over, has a couple of attempts at firing at full throttle, then nothing.

Going to stick my original carbs back on and give it another crack,but i'm stumped.

All the coils test out right, both cdi units work, both ignitor sensors work, everything from both bikes test out perfectly but it just wont fire.

Both bikes ran fine (well, my original with the blown hg ran a bit naff) before the swap, which is why im so stumped

Anyone got a suggestion? At the moment i'm tearing my hair out, I just want to go for a ride, all this amazing weather the last 4 weeks (well,apart from the last few days) i'm itching to get out on the bike

Any suggestions would be greatly appreciated

I had a old suzuki gs 450 and i sold it new owner said he just sprayed some petrol into the carbs and got it statred i tryed and tryed and gave up

[kiwi-on-wheels]

Well, I got the second set of carbs cleaned up, cleaned out the jets and bench balanced.

This set dont piss petrol out everywhere either


Try kick it in the guts, it feels like its trying, it kinda splutters but doesnt properly fire.

If I wind the throttle open fully it splutters a bit more, but still, no firing.

Taken the spark plugs out, they are clean, gave them a gentle scuff up with a plastic brush head on the dremel, they came up mint. Left the plugs out for a couple of days, going to be trying to get it going sunday as im working in the city from Monday and really dont want to be taking in the car.

[eldog]

Well, I got the second set of carbs cleaned up, cleaned out the jets and bench balanced.

This set dont piss petrol out everywhere either


Try kick it in the guts, it feels like its trying, it kinda splutters but doesnt properly fire.

If I wind the throttle open fully it splutters a bit more, but still, no firing.

Taken the spark plugs out, they are clean, gave them a gentle scuff up with a plastic brush head on the dremel, they came up mint. Left the plugs out for a couple of days, going to be trying to get it going sunday as im working in the city from Monday and really dont want to be taking in the car.

Sounds like you need someone (NZSpokes) to have a quick look. Probably something really simple.

[kiwi-on-wheels]

Id hope so, im spending Sunday tinkering....

[eldog]

Id hope so, im spending Sunday tinkering....

I am no mechanic, but start from the beginning,

new fuel, get rid of anything in the tank, carbs, floats etc
check oil in sump, no fuel or anything in there.

check spark and plugs are getting something.

put it together, check vacuum - no air leaks - rubber does degrade
fuel coming through clean - I assume there is a choke.
Battery upto scratch, not just 12V and 10.9 when turning over, check voltage at starter.

hope its not something more serious.

remember for engines
fuel, oxygen, heat/spark/energy will start a flame.

for other things usually only require oxygen to start something smouldering........ :2thumbsup

[nzspokes]

Well, I got the second set of carbs cleaned up, cleaned out the jets and bench balanced.

This set dont piss petrol out everywhere either


Try kick it in the guts, it feels like its trying, it kinda splutters but doesnt properly fire.

If I wind the throttle open fully it splutters a bit more, but still, no firing.

Taken the spark plugs out, they are clean, gave them a gentle scuff up with a plastic brush head on the dremel, they came up mint. Left the plugs out for a couple of days, going to be trying to get it going sunday as im working in the city from Monday and really dont want to be taking in the car.

Plugs fully clean? No fuel? I would pour a thimble of fuel down each cylinder and try that.

[Big Dog]

May seem like a silly question but have you checked your firing order?

Sent via tapatalk.

[gsxr]

Plugs fully clean? No fuel? I would pour a thimble of fuel down each cylinder and try that.

http://www.crc.co.nz/Engine-Start/6895-92b6bebc-10a1-4592-a073-2fec45024cef/

Have you tried a squirt of Start You Bastard.

[nodrog]

how do you know the transplant motor is good?

[nzspokes]

how do you know the transplant motor is good?

How do know its not?

[kiwi-on-wheels]

Tried start yah bastard, no joy.
Firing order is correct, coils are good.
Plugs were dry, will try a bit of fuel down the neck Sunday.

The frustrating thing is that it ran fine before it came out of the old frame. Started easily, revved clean, fuel is fairly fresh, line filter is clean and can confirm theres plenty of flow, theres good spark, and atm im cranking it from a car battery, so that takes care of the weak start, its a 550cca grunter with a solid charge on it.

[nodrog]

How do know its not?

well it doesn't fuckin work for one.

[kiwi-on-wheels]

Both motors start and run. The motor that came out had a toasted head gasket, the one gone in is a minter. Nice and quiet too. Had it running, took it for a ride before the swap, felt a lot happier than the one its replacing

[nodrog]

Both motors start and run.

no they don't.

[kiwi-on-wheels]

They did before they were removed from the frames.

Which is why I dont get it, both motors were in running condition before they were swapped between frames, why the hell arent they working now

[nzspokes]

Have you ensured fuel flow to the carbs? Is the choke stuck open? How have you proven spark?

[kiwi-on-wheels]

Yep confirmed fuel flow to carbs, refills the float chambers happily. Needles are clean, smooth operation. Jets are clean.

Choke operates smoothly

Spark proven by holding a spark plug in each lead against the head, every lead and every plug has spark. Not a big fat blue one, more a softer yellow arc.

More earthing / more robust path to earth required perhaps?

[eldog]

Yep confirmed fuel flow to carbs, refills the float chambers happily. Needles are clean, smooth operation. Jets are clean.

Choke operates smoothly

Spark proven by holding a spark plug in each lead against the head, every lead and every plug has spark. Not a big fat blue one, more a softer yellow arc.

More earthing / more robust path to earth required perhaps?

Earth via frame? Or direct.
fuel in cyl not just carb.
air flow? Should have some air/fuel mix when turning over when plug out
Timing?
just thinking of things you might have dislodged/loosened when you installed it into bike.

[kiwi-on-wheels]

Earth via frame? Or direct.
fuel in cyl not just carb.
air flow? Should have some air/fuel mix when turning over when plug out
Timing?
just thinking of things you might have dislodged/loosened when you installed it into bike.
Earthed to engine casing. Which is Earthed to the battery through the starter motor earth.
Fuel is in cylinder as the plugs had a touch of wet when I pulled them out.

However, if I hold my hand over the spark plug hole and crank the bike, I dont get any fuel out of the hole.

Timing is via a cdi trigger wheel which has a keyway attachment to the end of the crank, no way it can be out.

[nzspokes]

Fuel is in cylinder as the plugs had a touch of wet when I pulled them out I dont get any fuel out of the hole.



Thats a problem. On a cold start it should be well wet. When turning over there should be a good mist coming out the plug hole.

Again try fuel down the plug hole.

[tigertim20]

Tried start yah bastard, no joy.
Firing order is correct, coils are good.
Plugs were dry, will try a bit of fuel down the neck Sunday.

The frustrating thing is that it ran fine before it came out of the old frame. Started easily, revved clean, fuel is fairly fresh, line filter is clean and can confirm theres plenty of flow, theres good spark, and atm im cranking it from a car battery, so that takes care of the weak start, its a 550cca grunter with a solid charge on it.

how can you confirm plenty of flow if the plugs are dry?.

[eldog]

Flow into carb not necessarily into engine:brick:

[kiwi-on-wheels]

What would prevent flow from carb to motor? Jets are clear, plenty of vacuum.

Will drop thimble of petrol down each throttle body and try that way.

Definately not getting a fine mist

I do however have the carb boot rings loose as the carbs have been on and off so much, might tighten those up and give that a go

[eldog]

I do however have the carb boot rings loose as the carbs have been on and off so much, might tighten those up and give that a go

you could always make up a spray bottle of soapy washer (from under the sink)
good way of detecting leaks/vacuum once it is settled.

cant do much harm apart from cleaning the bike.

[nzspokes]

What would prevent flow from carb to motor? Jets are clear, plenty of vacuum.

Will drop thimble of petrol down each throttle body and try that way.

Definately not getting a fine mist

I do however have the carb boot rings loose as the carbs have been on and off so much, might tighten those up and give that a go

Because for the first start it needs a chunk of vacuum to pull the fuel through the circuits in the carbs.

Pour fuel into the plug holes.....

[Icemaestro]

What would prevent flow from carb to motor? Jets are clear, plenty of vacuum.

Will drop thimble of petrol down each throttle body and try that way.

Definately not getting a fine mist

I do however have the carb boot rings loose as the carbs have been on and off so much, might tighten those up and give that a go

loose carb boots = air leak = massively lean....and suggest check choke cable operation. as someone said before plugs should be soaked if you have been trying to start full choke (and you mentioned full throttle as well...don't do that! normally you should have flooded it with that)

[nzspokes]

Running yet?

[kiwi-on-wheels]

Nope. Plugs wet, but still not firing

Flattened battery, chucked multimeter across the car battery im using to help diagnose, 10.5v cranking.

Soooo, both car and bike batteries are on charge, and i'll try again tomorrow

[eldog]

Describe wet:wait:

[gsxr]

Nope. Plugs wet, but still not firing

Flattened battery, chucked multimeter across the car battery im using to help diagnose, 10.5v cranking.

Soooo, both car and bike batteries are on charge, and i'll try again tomorrow

Maybe just maybe both your batteries are fucked .Each battery cell is 2.1 volts so you have 1 dead cell.
Charging it wont fix that youll still only end up with 10.5 volts.
Given that you need 12 volts for the starter it leaves nothing for the rest of the electrics.
It doesnt matter how big a battery you put up its arse if its not registering over 12v then its not going to be a happening thing
Appears to me you have both a battery problem and an air leak to compound your problem
As previously stated you need vacuum to drag the fuel and any air leaks will lean the mixture as well
Do the soap test as previously stated check vacuum hoses and get a new fucking battery

[kiwi-on-wheels]

Nah the battery is fine, iv just been trying all sorts of things and a lot of cranking so I expected a bit of flatness tbh.

Will check my loaded voltages tonight.

Carb boots are all tight now, no leaks there.

Describe plugs wet... They have a tiny amount of petrol on them. Not dripping off, more a light film

[nzspokes]

Did you pour fuel into the plug holes?

[kiwi-on-wheels]

Not down the plug holes as they drop a long way into the head, I went down through the throttlebodys

[eldog]

get a squeegee bottle or a funnel and a tube
I doubt it needs to be much, your not sinking the Titanic

fire in the hole?

[nzspokes]

Not down the plug holes as they drop a long way into the head, I went down through the throttlebodys

So now you have fuel but no bangs. So has to be spark. Are you 180 out?

[eldog]

So now you have fuel but no bangs. So has to be spark. Are you 180 out?

Nail on Head I reckon. :apint:
or the cable is faulty

[kiwi-on-wheels]

Nope timing bang on, coils match where they are supposed to, leads to the right place, plus wasted spark setup coils

[eldog]

Nope timing bang on, coils match where they are supposed to, leads to the right place, plus wasted spark setup coils

and you have checked the spark is happening

Clutch in
Neutral switch
kill switch
Air Filter

Just start from the beginning - don't assume anything

Whats coming from the exhaust

Take a photo of the spark plug see it you can put it on here Spokes may have a comment...

It sounds frustrating.....

[nzspokes]

Nope timing bang on, coils match where they are supposed to, leads to the right place, plus wasted spark setup coils

Are you getting back fires out the carbs or exhaust?

[kiwi-on-wheels]

If I cross the coils over so they are running the wrong trigger pulse it pops out the carbs.

Just cooked the starter motor. Got a couple of real good coughs out of it, but yeah, whoops.

Oh well, $50 for a new starter motor,continue the mission when it arrives.

[RGVforme]

If I cross the coils over so they are running the wrong trigger pulse it pops out the carbs.

Just cooked the starter motor. Got a couple of real good coughs out of it, but yeah, whoops.

Oh well, $50 for a new starter motor,continue the mission when it arrives.

:no:

Just sounds like weak as fuk spark now unless he is 180 out ....Time to resistance check coils and leads plug gap ect perhaps....

Some spark does not mean good spark.Motor running before replant or not.

Back to the basics chap take nothing for certain now check everything.

[kiwi-on-wheels]

Motor running before swap
Same plugs, carbs, loom, everything.
Got Honda manual, coils within spec, leads within spec, plug gap within spec.
Coil leads are numbered to coil and cylinder, thats all been checked through.


Its doing my head in aye...

[Rhys]

Sounds like a weak spark to me. Buy some new plugs, cheap way to know they are working well

[Icemaestro]

Battery voltages again? 12.8v unloaded is a health battery, 12.4 on its way out, 10v is a dead battery....


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[eldog]

Motor running before swap
Same plugs, carbs, loom, everything.
Got Honda manual, coils within spec, leads within spec, plug gap within spec.
Coil leads are numbered to coil and cylinder, thats all been checked through.
Its doing my head in aye...

I assume you got the new starter, have you had a go since?

Spark? - thinking Kill switch - may turn over but wont allow fire.
Not sure how tricky those crafty Honda guys were when it was made.
Damaged/loose/shorted/(blown fuse) et al - connection in wiring, its all possible in changing it over.

[kiwi-on-wheels]

starter should be here in the next day or so, its in nz with the courier. i have a spare set of coils, spare plugs etc so i'll basically tear it all apart, test everything, put it all back together again and try my luck

[nzspokes]

Going yet?