motorcycle mods

JGD (☼Travelguide writer) says on Nov 29, 2008, 10:38:

lpdiver says on Nov 29, 2008, 10:49:

Here is what you do...Get up on your tiptoes and drive something with more displacement between your legs. There is no substitute for displacement. Any mods you make will cost you more it the long run than trading up to a bigger bike.

ts

Remember what the monkey says, "Fuck money it's free"

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mranderson says on Nov 29, 2008, 10:52:

Yes your right, but I´m looking for a cheaper way to squeeze some extra horses out of the engine. I figured that rejetting the carb would be the cheapest way to do it but I don´t know any mechanics here with knowledge of that.

Boring out the cylinder can cause overheating? I wonder how much that would cost anyway.

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mranderson says on Nov 29, 2008, 10:53:

Getting a bigger bike is definately the best idea but I just can´t afford it.

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vicshere says on Nov 29, 2008, 12:42:

Jorge if you bore the cylinder to a bigger size I think you would also have to change out the crank shaft

for the few extra horse if that would not be worth the headache

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mranderson says on Nov 29, 2008, 16:06:

I want a freewind, but I don´t have a game plan to get one. Not yet anyway. I think I´d kill myself on that ducati...at least here in medellin. I´m still sticking to the idea of modifying the cbf 150.

Vic, you don´t have to change the crank to bore out the cylinder.

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vicshere says on Nov 29, 2008, 17:03:

if you increase the piston size or bore size enough you also have to change the crank cause of the extra torque

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Cheers Terry says on Nov 29, 2008, 20:11:

First of all, the CBR 150 R is nothing more than a bored up CBR 125 R so there's not much room to make appreciable performance gains anywhere.

The guy at the beginning of the thread who mentioned 9:1 comprehension ration must be thinking of old Harley's because there's no way the Honda's out-of the-box ratio is less than 11:1, so no possibility for gains there either.

You're talking about a bike with a bulletproof engine that (unfortunately) makes less than 20 HP, but what are you going to do? Live with it, that's all...

Good luck...

Cheers,
Terry

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Cheers Terry says on Nov 29, 2008, 23:13:

Perhaps these guys could help? ;-)

(Sign on a motorcycle shop in Villa de Leyva.)



Cheers,
Terry

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mranderson says on Nov 30, 2008, 07:34:

The compression ratio out of the box is 9.1:1. My owner´s manual confirmed it.

Of course there are ways to modify it. Performance exhaust, rejet, modify airbox for more airflow are probably the simplest and cheapest.

I just don´t know where to get performance parts or where to find a good mechanic who can rejet a carb and tune it properly after that.

Unfortunately I haven´t had much luck finding info on this specific bike on the internet. Apparently this bike is only common in colombia, india, and some other parts of europe.

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mranderson says on Nov 30, 2008, 07:51:

Vic, I´ve bored out cylinders on dirt bikes without ever changing the crank. Never had a problem with the crank either.

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JGD (☼Travelguide writer) says on Nov 30, 2008, 09:45:

Vic I never metioned boring the cilinder holes, I suggested the cilinder head only. I`d never bore off cilinders on a bike that small. Too much hassle. Be carefull not to do it in excess, the cilinder may colide with the cilinder head and that a bye bye engine. Also because of the few extra HP gained overheating could be a problem, Same with brakes, you`ll have extra power wich means more speed, therefore same brakes will need to stop a faster bike, You will need to improve them too (brake and heat dissipation capacity ...)

Other things that come to my mind are better sparkplug and cable.

CheersTerry, look what the FANALCA`s website (Honda`s manufacturer in Cali) says about their product (CBF 150).
http://www.honda.com.co/index_motos.php, on the top menu click on motocicletas/nacionales/Sport/CBF 150 then when it loads on the right hand side menu click on especificaciones.
Don`t talk w/o knowing, that`s speculation.

You are worried the US is going to invade and take the Venezuelan oil?... you are selling everything to them !!Peruvian Pres. Alan Garcia to Chavez

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Cheers Terry says on Nov 30, 2008, 10:50:

Jorge,

Actually I do know quite a bit about the CBR 150 R. I had one in Thailand for a couple of years and raced it in a modified production class quite successfully. They're a very popular bike over there and I'm intimately familiar with the internals.

Mine was a 2004, bore and stroke of 63.5 x 47.2 and a compression ratio of 11:1. That's standard right out out of the box. I have never heard of a Japanese small displacement bike running an anemic 9:1 since the '80's. Why Colombia would get such a de-tuned model is beyond me. It makes no sense whatsoever.

mranderson,

I have a thought... Does your bike have a "R" designation, or is it a plain 150 with no letter after the numbers? If it's plain, then it would be a very simple matter to upgrade it to the R specifications with the standard 11:1 compression ratio. As Jorge mentioned earlier this is a easy mod - any machine shop can shave a little off the cylinder head.

That said, we're talking about modifications that can be done for peanuts just about anywhere, but in Colombia, who knows. Colombia has almost no high performance tradition (is there even a road race track in the country?) so their mechanics may be useless at this sort of service that is common elsewhere.

Lastly, what does your operator's manual give you for bore and stroke dimensions? Are they the same as mine, 63.5 x 47.2? Also, what are your gear ratios? Does the manual say anything like this: 1: 3.083, 2: 1.941, 3: 1.500, 4: 1.227, 5: 1.041, 6: 0.923. Just curious...

Rubber-side down...

Cheers,
Terry

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mranderson says on Nov 30, 2008, 11:40:

Terry, I have a cbf 150. It´s not a cbr.

Bore and stroke is 57.3 x 57.8 9.1 : 1 compression ratio


Primary drive 3.350

1st gear 3.076
2nd gear 1.789
3rd gear 1.304
4rth gear 1.090
5th gear .937

final drive 2.866 Front sproket 15 rear sprocket 43

This bike is supposed to run about 115 or 120 at 9000 rpm in 5th gear. I´ve never been able to get more than 100 out of it. I changed the front sprocket to a 16 and the rear to a 43. I can still get it up to 100 but I can´t push it past 7000 rpm in 5th gear. So I need to unlock a few more horses from the motor.

The whole purpose of modifying is that I want to be able to cruise at 80 or 90 without such high rpm´s

I´m a little nervous about trusting a mechanic to bore out the top of the cylinder here. Unless I can find one who really knows what he is doing.

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Cheers Terry says on Nov 30, 2008, 12:01:

Your bore and stroke is almost perfectly square at 57.3 x 57.8 ?!?! Holy crap... and that 9.1:1 compression ratio just slays me...

Sorry buddy, but I can't suggest anything to you. Honda Colombia should be ashamed of themselves for selling an old design that's so crappy.

Save your pesos, and buy a better bike... sorry...

Cheers,
Terry

If you want a fairly easy-to-understand article describing the differences between your bore and stroke and how the R model approaches it, this is pretty straightforward:

http://en.wikipedia.org/wiki/Stroke_ratio

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Cheers Terry says on Nov 30, 2008, 12:55:

Gringoloid,

Now that we've completely demoralized our poor buddy Mranderson I wanted to thank you for the Ducati tidbits. We do share a love of Ducks.

I've been a road racer and hardcore sport touring biker for years. I've collected many Italian race bikes with Ducati my favourite by far. I owned 9 at one time, but finally bit the bullet so I'm down to only 2 now, a 998R and my original Mike Hailwood Replica that sits in a Harris Chassis. It's one-of-a-kind. I can't tell you how many beers I've won in Harley bars on kick-start bets. Years ago in Oregon the MKR's kick-back put one guy in the hospital.

Lastly, a bit of Colombian Ducati trivia... Warren "Zulu" Keuning who runs Tribu Film Productions on Calle 85 in Bogota has a big 1100 Multistrada. I'm sure its got to be one of, if not the only one, in Colombia. It's black and he rides it all the time.

Cheers,
Terry

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JGD (☼Travelguide writer) says on Dec 1, 2008, 12:00:

mranderson says on Dec 1, 2008, 17:20:

Jorge good point. I don´t want to have to run high octane gas.

I found a shop who said they could change the cylinder to a 185 or 200. They told me they could do it for about 500k pesos but I´m not sure how much more power this will give me for that kind of money.

I´m just not real crazy about changing out the cylinder. I´m still looking for a shop that knows how to mod a carburator.

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Cheers Terry says on Dec 1, 2008, 20:52:

The higher compression is not much of an issue anymore on modern bikes.

Fuel and ignition management technology is so advanced now that even with a carb (instead of fuel injection) mine ran like a dream on normal crap Thai gas. It spent its life at redline and there was never any pinging or detonation and it'd still do 160 kph with a 200 lb. guy on board.

I bet Colombia is simply buying older technology because it's cheaper, and like you say it's certainly not a performance oriented society.

Cheers,
Terry

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mranderson says on Dec 2, 2008, 08:12:

Definitely not a performance society from what I´ve seen. I´ve met so many people here who tell me how great the cbf is. It´s really just a better handling scooter.

I´m sure one reason is that older technology is cheaper. Another is probaby that most colombians just don´t know and as jorge mentioned, these bikes are mainly for commuting in the city.

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