Spark plugs?

[CookMySock]

I''ve ridden with you in the past and know your running 40:1 and everything seems pretty standard with your bike.

That's why it's running lean and getting hot. Take it back up to 50:1. Better still, go to Amsoil 100:1.

Steve

[Reckless]

dangee - yea ill have a play with the timing later on.

reckless - plug colour sits at a 1970s trend brown colour.

chop - quite likely

ill also go back to a 9. no sence in running it hotter than it needs to be

Doesn't sound to lean then and I think you can read a plug and jet reasonably well.
You can try knocking the timing back a tad Dangers way to see how it feels.
You can't to any damage retarding it like that but mark it so you can put it back to where it was! I wouldn't want you to accidently advance it anymore than it is now!

If you want to know where your start point or factory point is you will need a dial gauge. (If you weren't far away I'd do it for you).
Mount the gauge, find TDC turn the rotor "back" from TDC to what your book says. My Ktm is 1.6mm BTDC or 17° ("Before" Top dead centre). The plug fires before the piston gets to TDC to give the gases time to explode. The mark on the stator should line up with the rotor. You will need to be able to see the gauge and the marks at the same time as due to the magnetic pull of the magnets you will need to hold onto the rotor at all times.
Its really simple and quick then you will know where factory is and you can ride it and make judgement calls from there as to what plug you want to run etc.
Re chop Comment: Better check your Manual to see if its a BR8 or 9 that's standard for that model year.

[B0000M]

Re chop Comment: Better check your Manual to see if its a BR8 or 9 that's standard for that model year.

done that, it says to use an 8.

but if it runs a 9 happily, id rather use that. cold = good in my book

[Reckless]

That's why it's running lean and getting hot. Take it back up to 50:1. Better still, go to Amsoil 100:1.

Steve

Agree with your previous comments here DB but not changing the fuel mix to fix this. Every study, track test (with computer download and analysis) and dyno test I did more oil = more horsepower. That's the rule we always went by. 20 years karting always around 25:1 and I read here that the 2smoke road race boys are running the same. So if it was lean I'd be changing the jetting not the fuel mix. But a copper brown plug doesn't sound to bad as long as its not leaning out in a particular area.

Personally I'd have a gander at the timing, I simply couldn't help myself if I where B0000M LOL!!!

Just my 2c

PS B000M I/we can only give you Internet style advice mate take it or leave it!

[Reckless]

done that, it says to use an 8.

but if it runs a 9 happily, id rather use that. cold = good in my book

OK mate I think I've given you all the opinion and advice its safe to give over the net without being there up to you what you do with it from here!

Cheers

[B0000M]

OK mate I think I've given you all the opinion and advice its safe to give over the net without being there up to you what you do with it from here!

Cheers

thanks for the advise, its more or less brought me back to what i was thinking to myself, except now i feel better about it as other people seem to think its the way too.

[Reckless]

thanks for the advise, its more or less brought me back to what i was thinking to myself, except now i feel better about it as other people seem to think its the way too.

If it where me I'd checking it out. As Danger says you might have a much better riding bike at the end of a simple timing check and adjust! But up to you!
CYA

[CookMySock]

Every study, track test (with computer download and analysis) and dyno test I did more oil = more horsepower.

I submit that is because it was running leaner. The more oil you have in the fuel, the less fuel you have in the fuel, so you get more oil = leaner. You would get the same result adding more oil and jetting richer, except you would then foul heavily.

if it was lean I'd be changing the jetting not the fuel mix.

I agree.

With modern 2T oils there is no reason to run 25-40:1. That is old-school thinking. We did a whole season racing a B1 on 100:1 and it was mint until it did a water pump bearing and overheated and stopped. The result was a very slight piston score.

We have the same problem with another 2T engine. We run it at 100:1 and it fourstrokes heavily and won't rev. Too rich! But if we run it on 40:1 it runs bewdy, but fouls and is hard to start. So we left it on 100:1 and rejet it, and it's mint now.

But hey, I'd say you were more experienced than I.

Steve

[B0000M]

If it where me I'd checking it out. As Danger says you might have a much better riding bike at the end of a simple timing check and adjust! But up to you!
CYA

thats exactly what im planning to do. tonight hopefully

[Reckless]

But hey, I'd say you were more experienced than I.

Steve

NA mate I just talk to much LOL!!!
I think us karters and possibly the road race boys have discovered what all the literature I read said that: more oil = more ring seal = more compression = more horse power and as long as your not putting so much oil in that it inhibits the combustion you get more horsepower. 25:1 was the magic figure back in those days. Then of coarse you have to jet it to run well.
Dunno really but it made sense and showed on the lap times. Sorta gave a fatter more usable power. You know, the old 10% Faster out of the corners at 50K = 10% at the end of the straight at 150K theory. Seemed to give us alot more where we needed it and didn't slow the top end at all. Leen was thin sorta power and you have to be exactly in the zone to make the most of it. when your racing other karts (or bikes) they don't let you be there. We had Micron set ups on the kart which gave top speed and down loadable track analysis as well.
But I do agree modern oils will let you run much much leaner.

Just my humble opinion though, I'm officially qualified for nothing, just quite few years karting under my belt.

[Ride it till the red]

I think if Boom had bothered to take any notice of my past posts on the CR250 he will have already seen that I recommend an 8 series plug and retarding the timing slightly on this bike, but how many times can you repeat yourself before it gets through?

To retard the timing loosen off the stator and turn it a penny width or an 1/8" in the direction of the motor rotation, takes about 5mins.

That post was all the motivation I needed, whipped downstairs and you were right, approx 5 mins to return to my seat (with a coldie too).

Just to check I've done it right; bolt top and bottom to loosen, undo screw and take off bottom plate (keep in a box to use to return to standard setting). Rotate anticlockwise slightly now that bottom plate is gone with top plate having a slot in it and tighten at required point. Yeah?

Bike has an 8 in it currently but I have a 9 that I'll take with me on Sunday when testing but I'm hoping that 5 minutes will have fixed any possible problems?

My fingers are crossed. Spent hundred upon hundred on getting it ready so far this week so it better bloody go well!

[Reckless]

That post was all the motivation I needed, whipped downstairs and you were right, approx 5 mins to return to my seat (with a coldie too).

Just to check I've done it right; bolt top and bottom to loosen, undo screw and take off bottom plate (keep in a box to use to return to standard setting). Rotate anticlockwise slightly now that bottom plate is gone with top plate having a slot in it and tighten at required point. Yeah?

Bike has an 8 in it currently but I have a 9 that I'll take with me on Sunday when testing but I'm hoping that 5 minutes will have fixed any possible problems?

My fingers are crossed. Spent hundred upon hundred on getting it ready so far this week so it better bloody go well!

Danger is the man to comment specifically on the RM but I'm not suggesting in any of my previous posts this as a standard mod to improve/change performance! I personally wouldn't move anything without the dail gauge and factory specs. The thread only went this way because B000m was suggesting the specific symptoms his bike was experiencing. This is particular to him or someone having very similar issues. If your bike is going fine don't bugger around with the timing without knowledge and the correct dial gauge etc is my personal opinion!

Jeepers I don't want everyone here ripping off to the garage and moving their stators to god knows where??
If you advance them to much by mistake you can completely shag your engine!!

[Ride it till the red]

Danger is the man to comment specifically on the RM but I'm not suggesting in any of my previous posts this as a standard mod to improve/change performance! I personally wouldn't move anything without the dail gauge and factory specs. The thread only went this way because B000m was suggesting the specific symptoms his bike was experiencing. This is particular to him or someone having very similar issues. If your bike is going fine don't bugger around with the timing without knowledge and the correct dial gauge etc is my personal opinion!

Jeepers I don't want everyone here ripping off to the garage and moving their stators to god knows where??
If you advance them to much by mistake you can completely shag your engine!!

Sorry mate should have specified, as per another thread where Danger, Booom and others gave me a bit of advice I have recently picked up an 05 CR250.... Initial test ride showed signs of detonation but was on old gas. After fixing a few other things I'm hoping to get it out for a proper test on brand new gas this weekend but thought I'd retard the timing as per Danger's advice as it seems from what I've read to be helpful with these damn honda detonation problems. Just wanted to check I'd done it correctly.

As for the RM, it's a Suzuki so it goes bloody mint! Nuff said!

[Reckless]

Shit that scared me a bit!! Saw you rode an RM and thought you where having a go at that??
I'd still want to know where factory was before changing anything if it was me but each to their own!

BTW: The warning is there for anyone else reading through this thread!!

[Ride it till the red]

From what I can tell factory is when the bottom plate is in there. If it's there it's held solid but when taken off it reveals the slot and therefore opportunity to rotate.... Obviously a bit hard to explain over the net which is why I hoped Danger would pipe back up and tell me that my suspicions were correct just to ease my mind. With this being the case I have moved it 1/8th of an inch anticlockwise (direction of motor) from standard as reccomended by Danger and in other places and therefore slightly retarded the timing and hopefully eliminated detonation. I guess we'll have to wait and see!

Cheers for the warning mate, it usually takes me a fair bit of reading and rereading before I go and change something like that so it should be ok.