125cc Sportsbikes Forum banner
1 - 15 of 15 Posts

· Registered
Joined
·
7 Posts
Discussion Starter · #1 ·
Hi community!

I am new, not very knowledgeable in mechanics, but competent at following instructions and have repaired and serviced vehicles before, thanks to forums like this. So I am happy to join!

So a neighbour has a Honda 125nsr and I am trying to get it back on the road after being in storage for 15 years. It’s in good condition. After a new battery, spark plugs and new fuel, I couldn’t get it to start (it would turn over, but not fire up).

In the end, I took it to a motorbike garage and they said the carburetor is damaged, as can happen if left for years with petrol inside it. They handed me back the motorbike and the removed carburetor and said if I can find a new/reconditioned one, to bring it back.

Before doing so – forgive my naivety here – to me the carburetor looked fine (just a bit mucky). Except for one broken component (appears to be snapped). Is it repairable? I took a photo, but fail to identify this on exploded diagrams. It seems a shame to resort to a new one if a simple thing like this can be replaced?

Any ideas?

Many thanks!
Gas Automotive lighting Machine Auto part Engineering
 

· Registered
Joined
·
901 Posts
Its not broken imho. It is a power jet if im not mistaken. It is a dellorto phbh28rd?
 

· Registered
Joined
·
7 Posts
Discussion Starter · #3 ·
Its not broken imho. It is a power jet if im not mistaken. It is a dellorto phbh28rd?
Thanks Remy. It looks like a kind of pin and it has sheared off, but don't know if this causes enough issues for the who unit to be considered "broken"? I checked and as the code "Phbh28 fd". Does this help? Thanks again!
 

· Registered
Joined
·
901 Posts
As i thought its a power jet in the corner.

Can you take a better picture of the jet. If you get it extracted you just need a new jet
 

· Registered
Joined
·
7 Posts
Discussion Starter · #5 ·
Hi Remy. It's hard to get this in focus, but part of this jet is in the body of the carb, and the other is inside the cap. It looks like sheared metal, probably broken as they were opening up the carb to clean/service it.
I'm going to have to look at the motorbike and carb in detail, as the link you sent has this inside, but that's not what is left inside the carb.This cylinder (with hole) is not present in the carb. Going to be frustrating if they gave up and didn't return the parts. I will update this thread when I get an idea of what might be missing. In the meantime, any tips on pulling this jet out? WD40, maybe a screw and pull it? I'm going to have to look at the motorbike and carb in detail, as the link you sent has this inside, but that's not what is left inside the carb.
 

Attachments

· Registered
Joined
·
901 Posts
You have to try to pull it out. Look for pigs tail bolt extractor.
If thay doesn't work than..but you can get a dellorto phbh28rd of a cagiva mito or rs125 for example. And the jetting should be cery close. It will be much newer carb and they can be found for the price of the pig tail extractors. And i dont know where you could fint the jet that you need to extract. It is very very rare on a dellorto (only few models have the power jet) so even googling doesn't bring a single of then up (not a diagram or anything else)

You could also go for high quality keihin PWK clone (100$) but then jetting is unknown.
 

· Registered
Joined
·
1,607 Posts
carb is dellorto 28PHBH F/D (F/D means screws on the right)
best jetting is main=138 to 142 idle=42 power=65
goto dellorto.co.uk
the delta consumption in miles between main 138 and 142 about 8 miles
best plug BR9EIX (£12ish)
 

· Registered
Joined
·
7 Posts
Discussion Starter · #8 ·
Thanks Remy, merci a vous asaniard.

I got the pin thingymajig out. Photos attached. Actually with WD40 and very very gentle wriggling, it came out from both ends. I have the feeling the chap(s) at the motorbike shop didn't have patience with small things like this, because apart from this nothing else looks obviously broken.

QUESTION 1: Does anyone know the part number from here (I live in France, if there's a shop here, asaniard?)?:

QUESTION 2: There are other pin things that seem wise to spray with WD40, gently unscrew, and clean up (if no damage obvious damage, I guess they can be reattached?). And carefully push a needle through anything so everything is unblocked, which is about everything and explains why the bike turned over but never started. Any advice here (cleaning products, if parts are fine to re-use without obvious damage)?

Gas Metal Rectangle Auto part Fashion accessory
Gas Engineering Metal Machine Auto part
Musical instrument Wood Flooring Asphalt Floor
 

· Registered
Joined
·
901 Posts
Very nice work. Absolutely perfect way of doing stuf.

This is a choke jet, not a power jet as I thought (or at least it uses the same jet)
You can get these without a problem. Though it would only make it difficult to start, maybe but when it is closed it would work without a problem (if it was in choke function that is. Power jet is still diferent)

The type of the jet is def "7746 choke jet" type, just match your jet size number from the part you took out

Cleaning is best imho in pertol or petroleum (white spirit)
Wd40 can leave a sticky residue. A carb cleaner is the best (brake cleaner works the same and might be cheaper)
You can also use a compressor to blow out all the passages.

Ps most likely they broke it when disassembling it
 

· Registered
Joined
·
7 Posts
Discussion Starter · #10 ·
Thanks Remy! This has been great advice. Now instead of looking at a 230 euro new carb (as the shop suggested), now looking at a 6 euro fix. I agree, it must have broken when they opened it, then they had no patience with it.

Question 1: So this is a size 60 and it seems wise I just buy all I need in one go. What joints/rubber seals should I get?

Question 2: is white spirit OK also on the plastic floats? I guess so if resistant to the fuel. (then any new fuel lines I can just buy locally)

Question 3: eventually, would I need to prime with fuel the cleaned, but now dry, carb before trying start the bike? Or will it be sucked right in no problem? (<that's going to make me sound like a complete amateur I know)

Question 4: the fuel is going to be about 5 years old now (last time I tried to fix it). I guess that's OK to at least test the carb works again as it should have some life left in it. Then only the change the fuel to new once we know the carb works?

I will certainly update this thread until the bike works, hoping it helps others. If I can do it, anyone can!
 

· Registered
Joined
·
901 Posts
Q1 if you want get a "rebuild set" with or without float
Q2, yes it is ok, white spirit is petroleum (in purification process is produced between diesel and petrol), you can also use petrol for cleaning from Q4
Q3
, no need to prime it. just make sure it is flowing free from the tube (see Q4)
Q4. by no means should you use a 5y old fuel !. Even 1year is most often to much.
You need to drain that fuel it not good for anything any more! and rinse out the tank with additional fuel, at least 2-3 times 1L with a lot of shaking the tank in your hand. than use this fuel in Q2. Make sure your in tank filter is cleaned. Test that when you open the fuel tank fuel valve and that the fuel flows easily (0.5L in 20-30s max)
 

· Registered
Joined
·
7 Posts
Discussion Starter · #12 ·
Great advice, Remy. It might be a couple of weeks before I come back to this thread. First I need to find time to dry fit everything to make sure the bike came back from the shop with nothing missing, then proceed to order anything. But this is looking really encouraging. I owe you a beer.

I have a suzuki gs500 that's also been in storage for 5 years, so I think best I follow all your advice for that, too (luckily for this bike I have a Haynes manual).
 

· Registered
Joined
·
901 Posts
The problem with fuel is it ages and its components separate. And they are very nasty when they are separate :)
Looking forward to hearing back from your success!
 

· Registered
Joined
·
7 Posts
Discussion Starter · #15 ·
The problem with fuel is it ages and its components separate. And they are very nasty when they are separate :)
Looking forward to hearing back from your success!
Hi Remy. I was able to 'dry re-assemble' on the bike itself today. I am pleased as it seems the garage was cautious not to lose anything. I emailed dellorto.co.uk to ask if they do any service kits (for all the o-rings, gaskets, etc, I might need).

I don't think a Haynes manual is available for this bike. Are there any good instructions available for full reassembly? This would also help me know what I might need to buy? If I would have taken it out, I'd have taken many photos. Unfortunately it wasn't completely clear to me how to reassemble. I am sure my mechanic neighbour could help otherwise.

I'll be cleaning it up and hopefully after xmas I will have time to try and get it all back together.

As always, thanks for all your advice!
 
1 - 15 of 15 Posts
Top