Keihin Thailand PE 28 Carburetor

[esspressolungo]

Just got my bike back from the valve job, when I passed Saengchai Motors I couldn't help stopping. So I had a look and found a Keihin PE 28 Carb made by keihin/Honda Thailand, i asked several times if this was the real deal or not. The shop manager guaranteed this was an original carb and not a replica or copy, I bought it for 1895.--THB. Many of you might know I had carb problems and tried to find a solution for my bike. The Keihin FCR 33 was the most powerful carb I ever had on, the Mikuni ™ 34 second place and now this Keihin PE 28 from Thailand.

Tomorrow I will ride it around town a little bit, seems like it is the perfect fit for the XR250, didn't need to re-jet and ran very strong from the very beginning, I will post pictures later, so you can have a look.

Was this the solution, so easy and just here? We will see tomorrow. I shall report more.
But for this money you cannot go wrong I reckon

 

[harrygps]

Is it not too small for a 250, Rudi?

 

[esspressolungo]

Is it not too small for a 250, Rudi?

Well what can I say, the original carb is now 32mm, the older XR's have 30mm, the CV carb are great carbs, but parts are very hard to come by and I was just tired of trying to fix the carb over and over again, the 28 might be a little small, but it's also a total different carb, that's used more for racing, a lot of guys here put it on the NSR with very good results, what did I have to loose. I read on thumper talk a lot about carb for the XR's and most go up, but they also have big bore kits installed. Then I read about one guy putting a 28 mm carb on his XR with very good results, that gave me the green light to think this can work…we will see soon how the story continues...

 

[Loop]

Geez i got a PE 28 sitting in my spares box doing nothing 555

It was bolted onto my ZX150 but i ended up getting an original Mikuni for it but should have gone for an OKO 30ml D slide like i have on the KDX...which works really well on it.
From memory what i found was that the copy Keihin PE 28`s had a round main jet of which are abundant here in LOS and the originals hex main jet or something to do with the choke setup,not 100% sure but there was a slight difference somewhere but they are made in Chon Buri. They are still a round slide though so probably won`t make any difference.

They are a popular hop up part on the Wave racer type bikes here.

 

[esspressolungo]

O.k. so here's my impression after the first longer ride. Acceleration great no bog until about 80 km/h after that it start sputtering and doesn't accelerate anymore or very hard, cannot reach the top end about 125 km/h. I get a lot of blue smoke. Well it's a two stroke carb maybe the gas doesn't get burned right.

Any suggestions? Wondering to go up or down on main jet and pilot jet??? I just wished someone had knowledge about this, I am so tired of fiddling around, something bolt on and go, seems like I can open a small museum with different carbs soon….hahahah

 

[LUFC]

The carb wont be causing the blue smoke Rudi, its just fuel + air going in, so the blue smoke must be from engine oil. Even though its a 2 T carb your engine doesnt know that.
I would try going down on MJ first, if it did come from a smaller bore 2T it likely has a pretty big MJ.

 

[esspressolungo]

The carb wont be causing the blue smoke Rudi, its just fuel + air going in, so the blue smoke must be from engine oil. Even though its a 2 T carb your engine doesnt know that.
I would try going down on MJ first, if it did come from a smaller bore 2T it likely has a pretty big MJ.

Thanks Darren, I will check which main jet is on and tune it down from there, hopefully I will succeed this time….

 

[esspressolungo]

Little update: MJ 152 PJ 40 I think the setting is pretty close, it pulls nice and strong even in second gear uphill, so the bottom seems alright, now I need to adjust the top speed, after 80kms it's getting a little congested, maybe I will try MJ 145 and read the spark plug again

 

[harrygps]

Small carbs have a faster flow, that´s the reason for the goof acceralation. But on high RPM comes not enough gas. I´ve tried also a 28 Mikuni in my (Georg´s) DR, didn´t work. Carb is brandnew and for sale.

 

[esspressolungo]

Small carbs have a faster flow, that´s the reason for the goof acceralation. But on high RPM comes not enough gas. I´ve tried also a 28 Mikuni in my (Georg´s) DR, didn´t work. Carb is brandnew and for sale.

Harry, was ist das denn für ein Mikuni? ein TM oder eine VM, was willst Du dafür haben, sag mal Bescheid, geile Tour heute.