Ye Olde Rd400
- Thread starter SONICJK
- Start date
CarbsAndCylinders
Careful With That Axe Eugene
It happened to my on my H2. The engine buried the tach needle, I hit the kill button and it took a few painfully long seconds before it dropped revs and died with no apparent damage to the engine. I never thought about using the ckoke to kill it.
Brian
Brian
SONICJK
Reminds me of...me No, I'm sure of it. I hate him
I suppose I'll invest in a dial indicator.
I don't think the slides were stuck.
Any advice on figuring out why I'm only on one cyl? When it first started it would run on that cyl only in a very limited rpm range, now it doesn't run at all
I don't think the slides were stuck.
Any advice on figuring out why I'm only on one cyl? When it first started it would run on that cyl only in a very limited rpm range, now it doesn't run at all
SONICJK
Reminds me of...me No, I'm sure of it. I hate him
Okay so I need some help here.
I got it running, it starts on less than 1/2 a kick (i can even just push it over with my hand which is cool)
On the stand in neutral it revs freely and is running on both cylinders.
Once I try and ride it though its completely anemic. No power at all and won't rev over 5k.
Timing was set with a dial gauge to .079" BTDC (2mm) Then confirmed with a timing light.
The stock marks on the stator are nowhere near the marks I made after using the dial gauge, but I tried it on both settings with essentially the same results.
Spark is good and strong, battery is new and strong.
I have cleaned the carbs twice, i'll do it again but I'm fairly certain theya re clean :-\
Anyone have any other ideas?
Its currently without exhaust gaskets, I'm going to throw some in in a minute when it cools off but i feel like its highly unlikely that would cause this much drama.
I got it running, it starts on less than 1/2 a kick (i can even just push it over with my hand which is cool)
On the stand in neutral it revs freely and is running on both cylinders.
Once I try and ride it though its completely anemic. No power at all and won't rev over 5k.
Timing was set with a dial gauge to .079" BTDC (2mm) Then confirmed with a timing light.
The stock marks on the stator are nowhere near the marks I made after using the dial gauge, but I tried it on both settings with essentially the same results.
Spark is good and strong, battery is new and strong.
I have cleaned the carbs twice, i'll do it again but I'm fairly certain theya re clean :-\
Anyone have any other ideas?
Its currently without exhaust gaskets, I'm going to throw some in in a minute when it cools off but i feel like its highly unlikely that would cause this much drama.
The comment about timing marks being off is a bit of a red flag. They should be close enough to get it started. Even with the wrong points gap, they should open at more or less the right spot. I don't think we ever ran a 400 with points, but I don't remember a timing mark.
Revving like that is a sign of a really lean mixture. Either there's no fuel getting out of the tank and into the float bowls or jets are blocked. Start there.
Another possible reason for lack of get up and go is critters or wasp nests in the exhaust.
Revving like that is a sign of a really lean mixture. Either there's no fuel getting out of the tank and into the float bowls or jets are blocked. Start there.
Another possible reason for lack of get up and go is critters or wasp nests in the exhaust.
SONICJK
Reminds me of...me No, I'm sure of it. I hate him
teazer said:
No points, newtronics ignition.
I think I may have set the timing at .21" btdc instead of .79 so I'm sure that's messing it up.
There's definitely fuel in the bowls, float heights are set according to the manual,
Jets were just cleaned.
Exhaust was disassembled and cleaned so no problems there
I suppose I'll reset the timing and try again.
SONICJK
Reminds me of...me No, I'm sure of it. I hate him
teazer said:
Sorry forgot a 0, should read .021 and .079.
Changed it to 2mm btdc and no real change, it runs acceptably below 4k or so, shitty from 4-6 and then sputters and wont rev over 6. Feels like its on one cylinder but its running on both.
I'm at a loss and ready to torch the fucker :-\
What carbs, needle jets and main jets are you running at the moment?
With my first RD400, I ran pods and stock pipes and every time I rebuilt the motor after yet another meltdown, I went up another bunch of main jet sizes. I eventually changed the needle jets and that fixed it, but I was spending more on pistons than fuel for a while.
Do you have access to a dyno locally that you could strap it down and see what the air:fuel mix was doing?
Did you clean the carbs ultrasonically or just the obvious corrosion? I went back through the thread quickly and those carbs were pretty bad and it makes me wonder if there's still some crap in there.
Can you borrow a pair of RD400 carbs from someone that we know work, just to see if swapping them cures the problem.
You might also check the coils and that Newtronics - use a car type timing light and see if it still lights up on both sides as you rev it - or does it miss sometimes. If it's not a steady light, borrow some coils. I have sets of 3 ohm dyna coils on the shelf if you need a set.
Another thing to check is battery voltage. If it's dropping as revs rise, that could be the issue.
If you were closer, I'd suggest you bring it over, but that's not so simple from TN to northern IL.
With my first RD400, I ran pods and stock pipes and every time I rebuilt the motor after yet another meltdown, I went up another bunch of main jet sizes. I eventually changed the needle jets and that fixed it, but I was spending more on pistons than fuel for a while.
Do you have access to a dyno locally that you could strap it down and see what the air:fuel mix was doing?
Did you clean the carbs ultrasonically or just the obvious corrosion? I went back through the thread quickly and those carbs were pretty bad and it makes me wonder if there's still some crap in there.
Can you borrow a pair of RD400 carbs from someone that we know work, just to see if swapping them cures the problem.
You might also check the coils and that Newtronics - use a car type timing light and see if it still lights up on both sides as you rev it - or does it miss sometimes. If it's not a steady light, borrow some coils. I have sets of 3 ohm dyna coils on the shelf if you need a set.
Another thing to check is battery voltage. If it's dropping as revs rise, that could be the issue.
If you were closer, I'd suggest you bring it over, but that's not so simple from TN to northern IL.
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any news my man?how is the RD doing?
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any news my man?how is the RD doing?