Linhai Bighorn 260cc 2x4

MechanicallyMinded · 05-01-2021, 01:09 AM

Hello everyone,
I have a older model Linhai Bighorn 260 2x4. I bought this bike cheap, quite some time ago. It was in a field stripped with nipples still on the tires. I have slowly tinkered my way back to a complete bike. Rode it and was completely disgusted with how it ran.

Before I go much farther let me say, this is my "loaner or secondary" bike. Nice to 2up with the wife and stuff. It doesn't see much use, but I do want it to be amateur proof, for a buddy or two.

Now, the hardened duct work cracked and things got bad. The manifold cracked and it was worse.

Ordered new intake manifold for rocketa/manco. Fit great, re-installed and ran like mud. Backfiring, spitting raw gas, erratic idle. I knew I needed a re-jetting and I despise these carbs. I took it off, pulled the jets, put the jets in a bag and the carb in the trash! Much better!

Ordered a 30mm pwk flat slide, jet kit, pvc for ducting, and began my adventure.

I have a decent running bike right now on a 140 main. Problem is I am having a hard time telling what my secondary is doing. I do not know if the slide needle has clip grooves or not, haven't made it that far yet.
Starts good. Seems to idle slightly rich, loads up at idle over time, and just as the throttle is first pressed it stumbles until the needle is picked up. After that, throttle rolls on and off smooth and W.O.T. is better than ever. Thing sounds like a jet ski.

My question is has anyone gotten a good base with a pwk on a 260 linhai.

It looks like I will land mid spectrum on the main, but very lean on my secondary. Is this a usual characteristic for this engine? It goes against what I want to do from habit. Even worse, that means the carb shipped with a too small main, and a too large secondary. Sounds off too... I assume it was aimed toward a 90-150cc expansion explosion diversion converter.

Either way, it might run 8n ford that way.

What diameter carb and jets are you running? Don't get wrong, it is wayyyy nicer than before, but still... not RIGHT. I will swap more jets tomorrow. And I will post up some pics of what I have done.
Sitting on a 140 main and 40 secondary. Seems to want leaner at idle. Choppy and loads up after 20 seconds or so.

Thanks for taking the time to read! I expect my personal pan pizza coupon now.

05-01-2021, 01:09 AM	#1
MechanicallyMinded Join Date: Oct 2019 Location: U.S.A. Posts: 13	Linhai Bighorn 260cc 2x4 Hello everyone, I have a older model Linhai Bighorn 260 2x4. I bought this bike cheap, quite some time ago. It was in a field stripped with nipples still on the tires. I have slowly tinkered my way back to a complete bike. Rode it and was completely disgusted with how it ran. Before I go much farther let me say, this is my "loaner or secondary" bike. Nice to 2up with the wife and stuff. It doesn't see much use, but I do want it to be amateur proof, for a buddy or two. Now, the hardened duct work cracked and things got bad. The manifold cracked and it was worse. Ordered new intake manifold for rocketa/manco. Fit great, re-installed and ran like mud. Backfiring, spitting raw gas, erratic idle. I knew I needed a re-jetting and I despise these carbs. I took it off, pulled the jets, put the jets in a bag and the carb in the trash! Much better! Ordered a 30mm pwk flat slide, jet kit, pvc for ducting, and began my adventure. I have a decent running bike right now on a 140 main. Problem is I am having a hard time telling what my secondary is doing. I do not know if the slide needle has clip grooves or not, haven't made it that far yet. Starts good. Seems to idle slightly rich, loads up at idle over time, and just as the throttle is first pressed it stumbles until the needle is picked up. After that, throttle rolls on and off smooth and W.O.T. is better than ever. Thing sounds like a jet ski. My question is has anyone gotten a good base with a pwk on a 260 linhai. It looks like I will land mid spectrum on the main, but very lean on my secondary. Is this a usual characteristic for this engine? It goes against what I want to do from habit. Even worse, that means the carb shipped with a too small main, and a too large secondary. Sounds off too... I assume it was aimed toward a 90-150cc expansion explosion diversion converter. Either way, it might run 8n ford that way. What diameter carb and jets are you running? Don't get wrong, it is wayyyy nicer than before, but still... not RIGHT. I will swap more jets tomorrow. And I will post up some pics of what I have done. Sitting on a 140 main and 40 secondary. Seems to want leaner at idle. Choppy and loads up after 20 seconds or so. Thanks for taking the time to read! I expect my personal pan pizza coupon now. __________________ "It damn sure wasn't dug up out of the ground that way!"
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