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Just another day in paradise.....

9/11/2022

0 Comments

 
Customer
" I need a main jet that goes with a 37.5 pilot jet"
me
"Well, it doesn't work like that I'm afraid"
Customer
"So what size main jet is standard with a 37.5 pilot jet?"
me
"There isn't a standard main jet size, all bikes use different sizes"
Customer
"So you can't help me then" 
me
No, I don't think so
Customer
You're very rude, F**k OFF THEN! (slams phone down)

​Is it me? 

0 Comments

Postage Charges

21/5/2021

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One thing which REALLY annoys me is excessive postage charges.
I ordered 3 Amal  1 into 2 cable junction boxes from Burlen Fuel Services in Salisbury recently. The order arrived 6 days later by Royal Mail standard 1st class post. It was a "large letter" size envelope weighing 40g. They had charged me £7.50 for postage.
I send out many similar size and weight orders every day and charge my customers the actual Royal Mail charge of £2.60.
Profiteering on postage is pretty rife, it isn't good for the companies reputation but the man at Burlen was quite resolute that £7.50 is a reasonable amount to charge for post which costs them £2.60 and they have no plans to stop overcharging their customers. 
Another company which likes to make a few bob on the postage charges is CMS in the Netherlands who have eye watering postal charges for airmail to the UK.
The other side of the coin are companies like Fowlers in Bristol and Crooks Suzuki in Barrow who's postal charges are very reasonable. 
I think more people should question their suppliers on this matter as it seems to be that profit from postage is now accepted as normal business practice.
0 Comments

Blasted Carburettors

22/4/2021

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Had a set of 3 carbs from a Kawasaki S3 400 on the bench today.
Something I've not seen before, the owner had taken them to a soda blaster who blasted them complete without stripping them!
The owner then took them home and attempted to strip them down.
He got as far as damaging the bottom edge of a slide trying to lever it upwards to remove it and completely obliterating the shroud on the top of one of the needle jets.

The soda blast medium had of course jammed the slide into the body and already caused a fair amount of damage. How he reduced the needle jet to the state it was in, I'm not sure.
I've been ranting for years about the perils of taking carburettor bodies to general blasting companies who have no clue and in some cases, no interest as to the delicate machined bores and surfaces these instruments have.
Genuine spares for these carbs are now very scarce, even used parts are hard to find.
It's great shame these carbs have been damaged in such an unnecessary way. They look as if they were in very good condition pre blasting, they have all genuine parts fitted with very little wear.
Picture
Picture
Picture
0 Comments

YZ465 air adjusting screw

21/6/2020

0 Comments

 
I had a VM38 YZ465 carb in a couple of weeks ago for a rebuild.
The 465 is well known for poor hot starting and general carburettor misbehaviour.
I took a close look at the air adjusting screw which was not the normal short head type, it had an extended length enabling you to adjust it with your fingers.
I'm not sure if this is standard to the model or may have been an aftermarket part.
The problem was the part of the screw the spring fits over, was about 3mm too short. This meant that when you screwed the screw in to bottom it, to then screw it out to get the adjustment, the spring was becoming coilbound and stopping the screw hitting bottom by about 3 turns.
So when you then screw it out the 1 1/2 turns or whatever to get the adjustment, it was actually out 4 1/2 turns making the pilot circuit very weak.
We machined about 3mm off the bottom of the thread which ensured the screw bottomed correctly when screwed right in.
Unfortunately, I didn't take any photos at the time but it's worth checking the screw bottoms the same with and without the spring fitted to prove it's not the spring becoming coilbound.
0 Comments

Boring carburettors

21/2/2019

0 Comments

 
Picture
Recently received a set of 4 x VM34 power jet carbs from a TZ750 for UFO fitment.
The customer told me they had been bored out to somewhere around 35mm.
At first inspection, it was obvious there were problems.
The boring job looked like it had been done concentric to the original factory bore.
Because of this, metal had been removed at the bottom of the bore which would otherwise provide the bottom edge seal on a closed throttle. You will see from the photo that with a closed throttle, the slide sits quite high. This would stop the carburettor from achieving a fully shut throttle and may leave it with an “idle”. 
Overboring if there is enough metal to do so, is normally done slightly high to retain the sealing edge at the bottom of the bore.
The point of us machining the body after fitting the UFO is to make sure the slide sits down properly on a closed throttle. It is not possible to do this if the metal has been machined away.
 
The second problem relating to the overbore is the amount of fresh air slipping down the sides of the slides as there isn’t a sealing surface there anymore. You can see this quite clearly by the light shining through at the sides of the slide.
The diameter of the slide in a VM34 is 35.5mm. The same slide is used in the VM30, VM32 and the VM34. You can see if you bore the 34mm version any bigger, it will cause problems which cannot be addressed.
Unfortunately, I couldn't fit these carbs with UFO’s for the reasons above. The carbs are probably not usable in the condition they’re in. The bodies are probably scrap.





​

0 Comments

TZ350 Woes

14/11/2018

1 Comment

 
Recently had a new customer enquire about UFO's for his TZ350 which is fitted with VM38 power jet carbs. He sent me the bare carb bodies and the throttle valves to have the UFO's fitted. 
The carb bodies had unfamiliar ID numbers stamped on them so I did a bit of investigation work as to their original fitment. It seems they were originally fitted to a Rotax snowmobile engine and had been converted to run on the customers TZ350. I happened to mention to the customer after we'd done the work that they were ex snowmobile carbs and he should check that the needle valves (float valves) were of the correct flow rate, as the snowmobiles have a fuel pump and are fitted with low flow rate valves. These valves will not provide enough fuel for a gravity fed race bike.
He came back to me and told me the valves were #3.0. The correct Yamaha valves are #3.5 with 6 outlet holes.
This he said, explained why all of last season the bike would run lean and misfire on the straights.
I supplied him with a pair of the correct #3.5 OEM spec valves which cured the problem.
He declined the offer for me to build the carbs for him, so who knows what other incorrect parts are fitted...
Yamaha OEM needle valve  6 hole, #3.5 flow rate 
part number 23X-14107-35-00   
£24.95 each  in stock


1 Comment

UFO Inserts

12/3/2018

1 Comment

 
We've been supplying and fitting UFO inserts to VM carburettors since 2014, these simple inserts give the best power increase of any tuning aid available for the same cost.
It's highly recommended that you get us to fit the insert as there is some accurate milling work required to the carb body and the throttle valve to release the full benefit of the insert. 
We can normally turn your carburettor round in 3-4 days.
I quite often get follow up 'phone calls from customers telling me they are amazed with the improved performance after fitting the insert.
The insert works on both 2 and 4 stroke engines, we've fitted them to most types of competition engine which use a VM type carburettor.

1 Comment

Packaging

12/3/2018

2 Comments

 
Since Motocarb commenced business in 2007, we have used clear plastic grip seal bags when posting parts out to customers.
I calculated that we were using up to 3,000 grip seal bags per year.

We are now trying to do our bit for the environment by using Kraft paper envelopes for jets and other smaller parts, cutting down on single use plastic which would end up in land fill or the sea. It costs a bit more, but it felt like the right thing to do.
It's only a small move but I've asked my suppliers if they can do the same and send my orders in paper rather than plastic.

December 2018
My main Mikuni wholesaler now supplies all small parts in paper packaging rather than plastic bags as a direct response to my suggestion to them. If you use plastic packaging in your business, please consider using recyclable materials instead.
2 Comments

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