Need help tuning Lifan 140

[my67xr]

Might be the head that is warped still, give it another sand and remember not to move the sanding block too far in each direction to keep it flat, and let the paper do the cutting, don't use too much pressure.
You could use some freecut dry sanding paper, 180grit work's well and use good quality paper too like the Norton or 3M stuff.
The mounting face of the manifold look's good.

Tighten up the 4x head cover bolt's and see if it help's stop the leak.
Check that the spanner doesn't spring back a bit as you tighten it, if it does you will need to add an extra washer's to each stud under the dome nut's to stop the nut's bottoming out before they're tight

 

[locko90]

Well gave the head another hit with the sand paper. Got it looking better. Made up 3 more gaskets. A total of 5 gaskets put it all back on and still has a leak.

Im about ready to give up on this engine.

You think it would seal with all them gaskets and i got it really tight! Like how is air still getting in there ffs

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[my67xr]

Have you tried holding the flat edge of a ruler against it to check it's flat, should only need the 1 gasket

 

[locko90]

Nah dont have a flat edge. But im going to get that 140 out of it now, and that way ill be able to work on it more easily.

I swaped the inlet manifold and 26mm carb off the 140 and put it on the 125 i got there. Didnt even have to tune the carb! And its running AWSOME!!!

Omg its so good to open the throttle with out backfiring and dying! Just acceleration .

So that 125 is going into the pit pro untill i sort out the 140s air leak.

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[gottagetacheaperhobby]

You can use anything flat as a straight edge, doesn't have to be a ruler, just straight..

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[locko90]

yeah well its a bit hard to work on the engine in the mounts man with the oilcooler lines exhaust pipe in the way. its to tight a space

ill work on the engine when shes sitting on the table.

but for now the highest priority is getting the 125 in the bike. I just wana ride im over working on it bro!
I got a 125 there.... just guna chuck it in the pit pro and be done with it.

 

[locko90]

Old pit bike striped down. Got the 125 allready for install.

Dont know if ill get it all done tonight.

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[locko90]

Maybe soon ill be getting one of them pitsterpro 160 ho engines for the pit pro. I been looking at them but thought ill hold off for a bit.
I see there 640 from dhz.
Are these engines any good ?
Will my dual exhaust fit in it ?
Wouldnt mind buying a second hand engine.

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[gottagetacheaperhobby]

They are a great engine, with tons of upgrades available. If your dual exhaust fits your 140 and 125 then it will be the wrong bend at the header for the 160, but you can get a adapter for them, I have heard of a few forums that you can get away with using 2 copper crush washers to make up the difference to..

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[locko90]

What do you mean by the wrong bend ? Whats the header pipe ?

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[my67xr]

Header pipe is KLX style, so the bend is a bit off, and the end where it goes into the head is different.
KLX use 8mm stud's too not 6mm like CRF.

Pitsterpro/DHZ have these for sale to adapt them
Pitster Pro - NCC Pipe Adaptor

CRF style flange

KLX style flange

These are the copper gasket's Stu mentioned above, you can sometime's get away with using 2 to adapt the exhaust's.

You can also do a cut and weld job, and drill out the hole's to make your pipe fit the Z160HO head
An exhaust shop would charge maybe $20 to do it.

 

[locko90]

dammm I just got the 125 going in the bike was a big job swaping them 2 engines!!!

and to be honest it just dosent have enough power , its reving its head off and running sweet but not much wheel spin acceleration which is what I want.

I was just dead set ringing dhz about postage of the 160ho but there line was busy. and now im having second thoughts like maybe I should just fix the 140..
and theres probably more work to be done to that pit pro frame.

for one the swing arm bearing gota be replaced, and the rear wheel is bent or something gota, have bolted in on an angle so the rear sprocket lines up with the front sprocket!

im not sure what causes this but if I don't have the wheel on an angle the chain comes off cuz rear sprocket is on a angle that makes chain come off, like hard to explain but the rear sprocket points in towards right side when tyre is in line with the shock absorber.

so yeah if im going to chuck a nice 600 dollar engine in the frame I kinda wana fix the frame up a bit and also replace suspension.

not just wack it in there and then have the chain fly off an d crack the new engines case lol

 

[gottagetacheaperhobby]

If I was you I would just throw 600 at a second hand atomic fuse or older dhz outlaw with a 160 in it. I saw one on fb in adelaide for 400, kid didn't know how to start it and it was kicking back on him.

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[locko90]

Nah man i like 5he way this bike handels i feel comfortable on it. Just needs more power.

But if i go and get the 160 for my bike im looking at doing more work aswell

And yeah just wish there was more pittys for sale atound my area.
There was a 160 pit pro big wheel just like mine. Guy had 1600 on it lol.
I paid 200 for mine

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[locko90]

I ended up buying the z160 ho. So about the cut and weld job for the pipe where would i have to cut pipe ? And can i use my 26mm Mikuni carb on the engine?

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[my67xr]

The old Braaap Daytona 190's like mine come out with the 22/26mm Mikuni fitted standard
Best carby for them is the Oko 26, #38 pilot, #102 main
OKO 26MM FlatSlide Carby Kit ? OKO ? Buy Online Australia at DHZ

Next i'd start looking at new stronger handlebar's, new fork's (GPX black label's) and a new rear shock (DNM) and better brake's, because that new 160 will go a lot faster and you'll definately feel it through the handlebar's and suspension

The exhaust you will need to fit it and then work out the best place to cut it to suit then have it rewelded.
The thick ring on the end will need to be shortened too.

 

[locko90]

that's sucks about the exhaust is it the right diameter, maybe I could just heat the metal up and bend it to get the right angle ? any way ill probably take the bike to an exhaust shop and see if someone can do it for me.

ill definitely be looking at getting the oko carb down the track a bit.

but will I be able to run the engine all good with the Mikuni its got the 95 main and the 20 pilot. should I get different jets for it

 

[my67xr]

The pipe size will be the same, it's just the length of the flange that goes into the head, the hole size for the stud's, and the angle it come's off the head at

See how the Mikuni goes, the #20 pilot will be fine.
With the main jet, if it seem's to hold back at high rpm's (feel's flat) then try 1 or 2 sizes bigger (#97.5, #100), but i think the #95 should be fine

 

[locko90]

ive just noticed that the inlet manifold that comes with the 160ho is fairly tall, can you get shorter ones for it? not sure if its goin to have enough space to fit carby under tank.

 

[my67xr]

There is but it come's at a price- TB V2 Head Rear Facing Intake Kit ? TB Parts ? Buy Online Australia at DHZ

I reckon the stock manifold should fit though, it's only 85mm high if it's the one i think it is marked FA 3Y