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Exh. port fitting problems with a FMF 4.1 & YX160

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For those of you who have a YX engine with the KLX exhaust port and an FMF 4.1 pipe; did you have any problems with the fitting / alignment of the headpipe to the exhaust port?

I just installed a 4.1 on my OGM 160 and the headpipe/port angle is off. I can get the header to fit into the port, but it isn't all the way in and the can is angled upwards about a 1/2" above the stock mounting hole on the mount. The header flange is bottomed out on the head when the nuts are tightened, so you cannot tighten it any tighter to pull the header further in the port. Crank it and it leaks a little because the header isn't bottomed into the port, against the gasket.

Are you guys running doubled gaskets (or?), or do I have a tweeked exhaust?

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My buddy had issues with his 4.1 on his yx150....i'll show him this thread to see what he thinks.

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Scott,

If I remember correctly some of the Earlier (OGM Yx 150 Motors) had a slightly different Honda crf 50 style exhaust port design on there heads and GPX Yx 150 motors had the KLX 110 exhaust port design on there motors...they look the same but the port angles are different.

there is a fix a exhaust adaptor that corrects it.

it sounds like this is the case

OGM went with their design so that people would not have to go out and buy new pipes and could use CRf50 pipes when they swaped motors.... it was sort of a 50/50 exceptance with the design.... Other companys on the other hand saw that now people could buy new pipes from them as upgraded stock (klx style) or(FMF klx style) pipes off them and make more money

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Hmmm.... This is supposed to be a last batch YX 160cc '08 model.

Vince? .... Alex?

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Hmmm.... This is supposed to be a last batch YX 160cc '08 model.

Vince? .... Alex?

Does your motor has 6mm exh studs and the FMF 4.1 KLX pipe will not fit ?

please verify

as far as you question about your order , OGM only ever got one batch of SX160

SO

your bike is the latest 08 version

(other older 08 versions were SX150)

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Does your motor has 6mm exh studs and the FMF 4.1 KLX pipe will not fit ?

please verify

I have no idea.

I was under the impression from various threads that the latest OGM 160cc bikes had the KLX head/port? I'm getting frustrated quickly. This is a FMF 4.1 Ti pipe.

The header is also hitting the subframe in two places as well as the mount being too high.

Here is what I have. Is it a CRF port on a KLX head?

fmf.jpg

fmf1.jpg

fmf2.jpg

fmf3.jpg

fmf4.jpg

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Do you have any crf pipes (or access to) around to slap on to see if it lines up?

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Nope. It's almost got to be one. The header angle visibly differs from the OGM header when comparing them.

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Nope. It's almost got to be one. The header angle visibly differs from the OGM header when comparing them.

BINGO

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So there is no truth to the late OGM bikes ONLY coming with KLX ports? Instead, it was a toss up to what you ended up with. Only the China-man knew for sure.

Why in the .......... Screw it, nevermind. Let me go take another blood pressure med. Ya know, I never needed meds before owning a pit bike. I thought women were the only ones that could drive a man to drink?

Looks like I'll be giving NCC a ring.

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the studs look to be 8mm

if the top intake port is "flat" and not angled then its a honda or A type head

were sorry for the confusion and we will do what it takes to help you

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I am not familiar with the difference between the two intake ports. I would assume that I have a "Flat" style intake - crf style? Looks like it to me in the photos below.

70kick.jpg

uni1.jpg

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yep thats the CRF50 Exhaust Port (yx klx style head)

those were suppost to be gone almost a year ago....:banghead:

actually all you need is a new Yx 150 or 160 head or TB V2 Head to fix it but then your stock pipe will not be any good.

Whats next...:)

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Whats next...:)

You ain't shiitin. One of my goals of getting out of riding the big bikes was to lessen the load on my wallet. Before long I'll have as much in this bike as I did in my CRF250R!

Don't get me wrong, I love to tinker and work on bikes. I've always performed my own maintenance, but with Jap bikes at least you have some consistency and reliable information on the bikes. This is ridiculous.

Someone tell 100% what I need to make this fn thing work. Adapter? Spring has arrived and we are ready to ride.

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well your pipe should line up with the hanger in the back..for 1 thing it dont look like its going to no matter what.

but there is an adaptor..but someone owes you an explanation about the head ...

your kind of out the cost of a Pipe that does not fit "Big Bucks"

what you need is the correct head and (new Intake) not some rediculas exspencive leaky exhaust adaptor that my friend is "Hackning" the bike shouldn't be your issue...:)

when this first appeared (crf 50 style port) we cut and re-welded the pipe to fit " Perfecto " and had a custom welder stitch the pipe up with a beautiful weld

No offence to the Dealer I know who it is..... you dont make the bike but the head issue puts a big dampening on anyone looking to modify the bike and the customer get stuck in a expencive situation

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Hey P50,

thought you knew more than that about these engines?:thumbsup:

That is the exact same engine and head setup as what the Medina uses. And this is a prime example of how DIFFERENT they can be, even though they appear to have come from "the same factory in China".:usa:

gen_bike_1.jpg

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Hey P50,

thought you knew more than that about these engines?:thumbsup:

That is the exact same engine and head setup as what the Medina uses. And this is a prime example of how DIFFERENT they can be, even though they appear to have come from "the same factory in China".:usa:

gen_bike_1.jpg

there is 4 or 5 Versions of that Head alone (different internals, different intake runners, and different Angles on the Intake and exhaust ports) also there is 2-3 different versions of lowerends. And everyone that has a 160cc seems to have a bad run of them..... Again

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Whew, just got back from a productive weekend the lake. Had a great time with them family filling zip-lock baggies with Crappie fillets.

Everything's cool at the moment with the bike. Trying to work out the best solution with T-bolt and NCC. Gotta get-er-done though. Local schools (including my sons) have spring break second week of April and we plan to spend several days at Durhamtown Plantation - the Coolest Off-road park East of the Mississippi !

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Whew, just got back from a productive weekend the lake. Had a great time with them family filling zip-lock baggies with Crappie fillets.

Everything's cool at the moment with the bike. Trying to work out the best solution with T-bolt and NCC. Gotta get-er-done though. Local schools (including my sons) have spring break second week of April and we plan to spend several days at Durhamtown Plantation - the Coolest Off-road park East of the Mississippi !

theres got to be Many new take off "correct application" heads out there those adaptors can and have been known to leak.... just keep that in mind.

I saw one over @ PM for $75.00 + shipping new take off w/cam included

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