Break in questions...

MotoMike

MotoMike

Member
73AMC said:
Well I got the honda jet and its too big. It wont thread in. How can I figure out what size this jet is?
Click to expand...

The main jet in your last pic looks like what is commonly referred to as a Keihen small round type... Honda uses P/N 99102-GHB-0XX0 for this type of M/J. The size is the second and third digit of last segment of the P/N. So, for a #90 the P/N would be 99102-GHB-0900 These main jets are available in increments, for example #78; #80; #82; #85; #88; #90; #92 and so on. For tuning purposes you'll want to get a few different sizes... they will come in handy down the road if you want adjust for temp and/or altitude.
 
6

69ST

Well-Known Member
This is not an "I told you so".

That said, this is why I stick with Mikuni & Keihin carbs. Parts support matters, especially when you're doing anything that requires tuning/dialing-in.
 
7

73AMC

Member
racerx said:
This is not an "I told you so".

That said, this is why I stick with Mikuni & Keihin carbs. Parts support matters, especially when you're doing anything that requires tuning/dialing-in.
Click to expand...

The carb actually came with the engine kit I bought. I did not choose it. If I was to purchase a carb I would have bought something that had support locally.
 
MotoMike

MotoMike

Member
Hey 73AMC, I was just looking through some Main Jets out in the man cave, and was able to confirm Honda's part number scheme regarding Keihin Main Jets. I read an earlier post in this thread someone referred to ordering Main Jets with P/N 99101-GHB-XXXX, those are in fact the Keihin large round type, with a larger thread size. If this is what you ordered, that would explain why it won't thread into your Needle Jet. Again, looking at the pic you posted, I'm fairly confidant that you need the Keihin small round Main Jet's, P/N 99102-GHB-XXXX series. If I'm wrong (wouldn't be the first time) and these Main Jet's don't fit, then I'm going with what racerx is saying, and get yourself a genuine Keihin carb.
 
MotoMike

MotoMike

Member
I'd think that your local Honda dealer should have a half way decent selection of Keihin Main Jet's in stock, if not that would be like not having spark plugs, or oil filters in stock... pretty lame dealer, IMO.
 
OLD CT

OLD CT

Well-Known Member
Agree with MM.I would not order them from dratv unless your positive it will work.Go to any local dealer Yamaha Honda Kawasaki Suzuki first.Why take a chance getting the wrong jet with high shipping fees for a 4 or 5 dollar @ the dealer jet from the dr.This way it's in your hand to match it up also.If they don't have a match,than the jets arent available at all in most cases.Grab a carb that you know jets are really available.What ever carb you buy you will have to dial it in with a jet kit.
 
Last edited:
7

73AMC

Member
Took the whole jet assembly down to the dealer and asked them to try the small round kiehen jets and they still don't fit. Looks like its time for a new carb. This one is a 26mm, what do you guys recommend?
 
6

69ST

Well-Known Member
Measure the intake port ID. If it's 22mm, or larger, I'd go for a VM22, starting with #22.5 pilot/160 main jet combo. Worst case, you might have to drop down to a #20 pilot but that's highly doubtful; 125cc should move just enough air at idle to keep this carb reasonably responsive. As for main jetting, anything from #130 - #180 is possible, depending upon how much hp your specific L125 makes. If you don't mind throwing some extra bucks at the problem, for the sake of time, order a set of mains ranging from 140-170 and get to work testing.

FYI...if you compare your existing carb to the VM22, side-by-side, you'll probably be shocked by the real world size difference. 26mm is too much venturi for 125cc and less than 10hp and the folks who came up with your engine kit knew this. They also knew that appealing to the "bigger is better" mindset is effective marketing strategy.
 
MotoMike

MotoMike

Member
I think he is referring to the intake manifold, where the carb bolts up to it. That dimension should be no less than the carb ID, or slightly larger.
 
F

Frozen Cold

New Member
hey guys! heres the scoop...ive been lurkin for some time now...i pick'd up a '72 mini trail for $125 a few months ago. i was gunna get it run'n then ride it. hasnt been ran for 27 yrs...so i start'd ter'n into it tuh get it clean'd up....and, well....this things purty darn toot'n cool!!!


sooo...

i figure now,


im gunna fix this thing right and make a "rat rod" out of it... its all there, a little worn, but lookin nice and used with a shine!!!
the engine is going to be fresh and parts will be updated that are worn, such as handle bars, tires and such....
which is it??? dr atv? or chp??? chp doesnt allow you to order over the internet? correct???

any preferences???
 
Adam-NLV

Adam-NLV

Well-Known Member
Preferences?
I prefer the vendor who has the part I need at the price I want.
I've had positive transactions with both of these outlets. CHP is still old school and you gaotta give em a call in Tyler Texas.

When you call: Tell em Adam said to pull their head out and update their web site! It's 2012 for *@#$ sake!
Just kidding.:4:

Welcome to lilHonda.
 
Top