New high compression motor is knocking?

[hawaiirider]

Just had my xl 200 motor rebuit (same as 200x) the motor has a high comp 12:1 piston, big dg carb, dg exhaust, web cam race cam, titanium valves w heavy springs and clamp on uni filter.
it was dynotuned and runs excellent!
it runs great on pavement no issues at all, out on the dunes however it knock bad, sounds like both lower and valve train knock.
im running clear 93 octane with octane boost, no race gas, standard 10-30 honda oil
should i switch to race fuel? heavier weight oil?
the plug is white in the center, motor runs cool can spit on it and doesnt sizzle at all.
thanks for the help i dont want to blow my new motor up!!!!!!!!!!!!

[shortline10]

100 octane with that piston , pump gas won't cut it with 12:1 on an air cooled motor .
Octane booster doesn't work !

[hawaiirider]

100 octane with that piston , pump gas won't cut it with 12:1 on an air cooled motor .
Octane booster doesn't work !

thanks, and your right octane boost is going to be a campfire starter, thats about all its good for!
How bout my oil is the standard 10w30 OK?

[shortline10]

20w-50 in the summer 10w-40 in the winter .

[RIDE-RED 250r]

Agree: Octane booster is pure snake oil and the target market is kids who wear their hats sideways that drive Civics with a fart can and think that a wing on the back makes it hold the road better at 60mph, and that dumping race fuel in a stock engine makes it faster....

You need race fuel in that engine.

[hawaiirider]

[QUOTE=RIDE-RED 250r;1300078]Agree: Octane booster is pure snake oil and the target market is kids who where their hats sideways that drive Civics with a fart can and think that a wing on the back makes it hold the road better at 60mph, and that dumping race fuel in a stock engine makes it faster....

bahahahaa!!!!:lol:

[yaegerb]

I run 12:1 in my 200x and only use a minimum of 108 octane (as recommended by Powroll). I have never had a problem with it. 93 is way too low.

[RIDE-RED 250r]

I run 12:1 in my 200x and only use a minimum of 108 octane (as recommended by Powroll). I have never had a problem with it. 93 is way too low.


I seem to recall 11:1 on a naturally aspirated engine being the absolute cutoff regardless of timing and jetting adjustments for pump fuel as a general rule of thumb.

[90guy]

Agree: Octane booster is pure snake oil and the target market is kids who wear their hats sideways that drive Civics with a fart can and think that a wing on the back makes it hold the road better at 60mph, and that dumping race fuel in a stock engine makes it faster....

You need race fuel in that engine.
Watcha talking about there! hahaha! 12:1 need race fuel! Agreed on the octane booster It's garbage. Waste of money. Only one place sells race fuel here and that's over an hour away to buy it. So I can see why you tried.
http://i654.photobucket.com/albums/uu265/tumor633/photo23.jpg

[DohcBikes]

I seem to recall 11:1 on a naturally aspirated engine being the absolute cutoff regardless of timing and jetting adjustments for pump fuel as a general rule of thumb.
No.

Many naturally aspirated sport bikes run over 12:1 on 89-93 octane.

Old 2 valve Hondas are another story.

[El Camexican]

I'd be concerned with that white plug. You may want to jet up a few sizes and see how it runs. It should have a little color to it.

[hawaiirider]

I'd be concerned with that white plug. You may want to jet up a few sizes and see how it runs. It should have a little color to it.

i was concerned with it, but it runs perfect and is running cool, i spit on the motor didnt sizzle at all after sand hillclimbing?

[hawaiirider]

Watcha talking about there! hahaha! 12:1 need race fuel! Agreed on the octane booster It's garbage. Waste of money. Only one place sells race fuel here and that's over an hour away to buy it. So I can see why you tried.
http://i654.photobucket.com/albums/uu265/tumor633/photo23.jpg

dude that scene from the news checkin out the minimart episode you posted with layhee made me piss my pants i was lauging so hard, if yall dont know what im talking about watch trailer park boys, high definetion piss jugs episode, absolutely hilarious!!

[DohcBikes]

Top and bottom end noises but it runs perfect? I'm not being a Richard here but that don't make sense bro.

It does sound lean to me as well.

[El Camexican]

i was concerned with it, but it runs perfect and is running cool, i spit on the motor didnt sizzle at all after sand hillclimbing?

Sorry, I didn't realize it had passed the spit test, my bad.

[RIDE-RED 250r]

No.

Many naturally aspirated sport bikes run over 12:1 on 89-93 octane.

Old 2 valve Hondas are another story.

Well, not to get too sidetracked here, but those bikes have pretty sophisticated active fuel and ignition management systems that allow for that don't they?

I was more referring to a conventional carbureted engine that once jetting and ignition is set, thats how it is and doesn't have a system that keeps thing "in adjustment" during operation..

[DohcBikes]

Well, not to get too sidetracked here, but those bikes have pretty sophisticated active fuel and ignition management systems that allow for that don't they?

I was more referring to a conventional carbureted engine that once jetting and ignition is set, thats how it is and doesn't have a system that keeps thing "in adjustment" during operation..You said Naturally Aspirated engines, regardless of timing and fuel adjustment, are held to a max of 11:1 compression on pump fuel.

That statement is not true, so I just wanted to clarify.

Naturally aspirated means no turbo or supercharger.

Lots and lots of fuel injected engines are naturally aspirated.

So you meant carbed engines as opposed to fuel injected. I understand now.

[RIDE-RED 250r]

Well, given the question by the OP I didn't think it was really necessary to put in the disclaimer about modern fuel and ignition managed engines. I did say that was the general rule of thumb. And I do know what naturally aspirated means, probably didn't need that disclaimer either! LOL! ;) :beer

But we're good, I get where you are coming from. I was talking about the speed capability and limitations of a P-51 and you brought F-22's into the conversation! LOL!

[DohcBikes]

I seem to recall 11:1 on a naturally aspirated engine being the absolute cutoff regardless of timing and jetting adjustments for pump fuel as a general rule of thumb.

Well, we were talking about compression ratios and pump gas.

There are many naturally aspirated engines with higher than 11:1 that run pump gas.

I suppose if you meant carbureted, you should have said that, but you didn't.

You said naturally aspirated, so your statement is 100% false......no matter which airplane we are talking about.:)

And some beer for you as well.....:beer

[RIDE-RED 250r]

What I said was most definitely not false in context of the conversation. It was you who injected a modern exception to the rule, that is only an exception because of modern ignition management and fuel mapping. So if the modern tech allows the use of pump fuel at 12:1 safely by altering fuel mapping and ignition timing to compensate, you probably aren't getting the full performance benefit of that compression ratio anyway.

[DohcBikes]

Did the context require you to refer to his engine as naturally aspirated? Or were we supposed to assume he's running boost? Haven't seen a lot of boosted 200cc Hondas myself.

Naturally aspirated is a specific term pertaining to intake pressure. It doesn't take context to make what you said wrong, im sorry but it is wrong in any context, and that's all there is to it for me.

[RIDE-RED 250r]

Well, I guess I specified that possibly because I half expected somebody to nit-pick and let me know that its lower with boost. Or maybe its because I have been looking into setting up my small block with blower pistons, intake, and cam and putting a blower on that and that has been stuck in my head...(see how specific I was just then;)) But you're right, not too many boosted 200x's out there.

But it doesn't make what I said wrong in any way. Go back through this thread and tell me who was out of context.

When you refer to a cutting edge technology sport bike being able to safely run pump fuel at 12:1 it is only able to do that because the computerized fuel and ignition system is able to compensate for lower octane fuel using data input from knock sensors and maybe even exhaust temp sensors and de-tune fuel mapping and ignition timing. Its not because its some magical design of the engine components or the basic materials they are made out of. End of the day, unless your engine can automatically "de-tune" itself you won't run pump fuel safely for very long at 12:1...93 might be OK but that's probably pushing it.

And besides, Hawaiirider is it 12.5:1 isn't he???

And I still don't get what you think I said was wrong and why...was it the fact I brought it up or that I said 11:1 was the cutoff for safe running on pump fuel??

[El Camexican]

Did the context require you to refer to his engine as naturally aspirated? Or were we supposed to assume he's running boost? Haven't seen a lot of boosted 200cc Hondas myself.

Naturally aspirated is a specific term pertaining to intake pressure. It doesn't take context to make what you said wrong, im sorry but it is wrong in any context, and that's all there is to it for me.

Easy there buddy, you're starting to sound like Barnett is channeling through you:lol:

[DohcBikes]

Once again the Barnett comparison.

I was the way I am way before I knew who Barnett was, and its honestly offensive to hear this over and over. Nothing I do or say has a damn thing to do with how barnett acts.



No amount of extra info will make ride reds statement correct.

[86T3]

A little off topic and not trying to get into this argument but yfz450s can run up to 12.5:1 ratio on 93. Twin cams, 5 valves, liquid cooled but still carburated. Very far off from a 200x. I've always heard the older tech motors limit was 11:1.

[ezmoney1979]

A little off topic and not trying to get into this argument but yfz450s can run up to 12.5:1 ratio on 93. Twin cams, 5 valves, liquid cooled but still carburated. Very far off from a 200x. I've always heard the older tech motors limit was 11:1.

Took the words right out of my mouth. My YFZ runs good on pump non ethanol, 91 octane. 04-05 had 11.9-1 compression ratio.

[DohcBikes]

I'm very familiar with these numbers as well, I'm just not the type of guy that feels the need to prove myself, especially when I know I'm right.....hint hint.

:lol:

Ride red, I know exactly what you are saying pertaining to context, and its my opinion that you simply said it in a way that makes it not true in any context.

I also know that YOU know what you are saying, I just don't want people to read that statement and think it is true, that's all.

On another note.....

It wasn't two months ago that several long term members were attempting to convince people that they DO run 93 octane in their old 12:1 engines.......

Where are ya now guys?:wondering

EDIT: 86T3, I see no arguments here. Just a technical discussion:beer

[hawaiirider]

190356
heres the plug pic, has a little brown on it not much

[shortline10]

Plug looks good to me .
Not sure why a few got so far off topic , you can't compare the new hi strung water cooled motors to a honda 200cc air cooled motors they are 2 totally different animals . Race fuel is required with your motor .




190356
heres the plug pic, has a little brown on it not much

[DohcBikes]

190356
heres the plug pic, has a little brown on it not muchIts hard to judge by the pic because of the light but it looks lean to me.

Do you have any bigger jets? Would not hurt to try.....

And I totally agree that your engine likely wants race gas.

[RIDE-RED 250r]

A little off topic and not trying to get into this argument but yfz450s can run up to 12.5:1 ratio on 93. Twin cams, 5 valves, liquid cooled but still carburated. Very far off from a 200x. I've always heard the older tech motors limit was 11:1.

2 words... ignition timing.

Example: My boat has a carbureted GM 4.3 in it. Per the owners and service manuals, with the base timing set at 6 deg advanced I have to run 91 or better. If I want to safely run 87 I have to put base timing at 0 deg.

Modern carbureted ATV engines have more sophisticated CDI's than the machine in question.

In the case of the carbureted YFZ, that's how they get away with it...Liquid cooling helps buy some leeway as well.

But anyway, I'm done beating my head against a wall here....

[hawaiirider]

ill start with race fuel, then go up a jet if that doesnt do it, both main and pilot? also should i play with the ignition timing? i forgot to ask that

[yaegerb]

I don't know why you are messing with Jets/ignition to cure a pinging problem. Start with quality race fuel and go from there.

Go here: http://www.vpracingfuels.com/racing-fuel

Purchase 5 gallons of C-12. No more pinging!

[lokisbuddy]

Agree: Octane booster is pure snake oil and the target market is kids who wear their hats sideways that drive Civics with a fart can and think that a wing on the back makes it hold the road better at 60mph, and that dumping race fuel in a stock engine makes it faster....

You need race fuel in that engine.

omfg I just laughed so hard at that since my buddy was over while I was reading it and he drives a vw jetta with all the fast and furious trailprotrailprotrailprotrailpro on it. lol my 4 cyl stick shift ranger eats it.... god tuner kids make me smile. putting a wing on a front wheel drive car.

[RIDE-RED 250r]

omfg I just laughed so hard at that since my buddy was over while I was reading it and he drives a vw jetta with all the fast and furious trailprotrailprotrailprotrailpro on it. lol my 4 cyl stick shift ranger eats it.... god tuner kids make me smile. putting a wing on a front wheel drive car.


I like surprising them with the "tow/haul" function on my full size '06 Silverado every now and then too.... LOL!

[bkm]

Not to get off topic here, lol, but being able to run low octane gas in a higher compression engine has more to do with efficient combustion chamber design, piston dome, and cam timing. You can put a more efficient cylinder head/piston/camshaft combo in an engine and use the same ignition/fuel delivery system and be able to run more timing with a lower octane gas and make more power. No ignition or fuel system is going to overcome poor chamber/piston/cam design.

[hawaiirider]

so let me get this correct, if i install a spoiler and annoying muffler it will be better?

[RIDE-RED 250r]

so let me get this correct, if i install a spoiler and annoying muffler it will be better?

It won't just be "better"....it will be a full on race car!!! LOL!

[lokisbuddy]

yeah don't forget if you install a spoiler and stickers you go up 4 jet sizes and if you put monster stickers on then you have to add a bigger pilot jet ;)