RD03 - re jetting after removing restrictor ???

[holla]

Hi all, After Kjell came up with the information about RD03's being restricted (definately german ones, maybe others ??) A few people on here now are going to remove thiers.

I was under the impression that the bike wouldnt need re jetting as in theory the mixture wont change, it just restricts use of full throttle.

If anyone has differing opinions on this matter, I and several others on here would be very grateful for your thoughts

Thanks

Ian

[holla]

Its ok you dont need to reply to this, Ive found out that the standard jets are 125 for front carb and 130 for rear so my carb is jetted as standard.

So its out with the restricted rubbers and hold back all those horses .

Ian

[Kjell Lindberg]

You are right!
That's the standard jetting.

A small note of interest:
Honda installed a bigger jet on the rear carb
making the rear cylinder run richer and thus running cooler.

However there are other jettings for other markets.
I have have seen charts showing the jettings for the RD03
för different markets.

So how much money was the inlet manifolds?

I guess those seven extra HP came quite cheap.

I would expect you only notice them there HP's on higher revs

//Kjell

[holla]

I've ordered the inlet rubbers from wemoto for £17. I dont know what price genuine ones are but i didnt want to pay for honda ones then find out when they come they're the same as i've already got.

At the end of the day its only a rubber connector pipe so i cant see any difference in using the pattern ones. All i know is by comparing the 2 the wemoto ones have a much bigger internal diameter.

I'll let you know the difference it makes when i fit them............... and sort out the misfire

[grazie]

Inlet manifold £16.10 + P&P from Wemoto. (not looked at any other sites for prices)


http://shop.wemoto.com/pictures.dyn?u=25276qqq5828115


Some spend hundreds in the search for a few extra horses, so this could be a gift!

Looking forward to hearing the results.

[holla]

Inlet manifold £16.10 + P&P from Wemoto. (not looked at any other sites for prices)


http://shop.wemoto.com/pictures.dyn?u=25276qqq5828115

i think they must have gone up as i was quoted 17 pounds something for them. I thought for the sake of £1 its not worth arguing over in the search for those lost 7 horses

[grazie]

Quote : I thought for the sake of £1 its not worth arguing over in the search for those lost 7 horses


Too right mate.

Thanks both to you and Kjell for the homework.

Lucky 7 horses, fingers crossed


Graham

[Kjell Lindberg]

Ian, have you tried to cross switch the "CDI boxes"?
Or do you have the missfire on both cylinders?

Get your self a spary can with starting gas

When the engine is running on idle speed, start spraying the starting gas all around the carbs, inlet manifolds etc.

If you have a leakage in one of those areas, the idle will be affected, and the engine will run faster for a second or two.

It's a quick and cheap way to check for inlet leakages.

Missfire sometimes also occure if you have a leakage in the exhaust system, but this normally also includes back firing on over run, and can be detected by close inspection of the headers and silencers.

Have you checked the Air cut valves? (No 9)
Sometimes the diafraghm part get a small hole in it.








The earth cable from the battery sometimes comes loose, and this also affects the engine running.

//Kjell

[holla]

Thanks Kjell, I have ordered a new choke cable as mine was very stiff even with chokes removed but the chokes were free and clean. I havent tried swapping over cdi's as i dont know which cylinder its coming from.

I'll get some new exhaust gaskets as i didnt replace them when i removed the rear pipe to repair the heat shield mounting. I didnt reove the whole system as it was a nightmare trying to get to one of the nuts on the front pipe ( behind front downtube) so maybe with moving it around i might have developed an air leak ??. It did pop on over run even at 3,000 revs in neutral.

Next weekend i'll put new exhaust gaskets on and fit new inlet carb rubbers and see what happens then i'll try bypassing the fuel pump if all else fails.

I've taken the carbs apart and they were spotless ( at least on the inside ) although 4 hours with a toothbrush and wd40 and carb cleaner and the outside is spotless as well . I took the diaphram out of the top of the carbs and they were fine as were the air cut off valves.

I'll keep you posted.

Thanks Kjell

[Kjell Lindberg]

Here is a trick we used in the Army, out in the fields, when trying to locate a missfiring cylinder:

Use a screwdriver!

While running the engine (but obviously not driving the bike at the same time,,, )

Put the sharp end on the object you are about to inspect, (in your case
one of the cylinder heads), and your ear firmly on the top of the screwdrivers handle.

Then check the other cylinderhead the same way.

You should hear a different sound from the one with the missfire.

The faulty one should have a disharmonic sound with irregular knockings or "pings" or whatever, the good one should have a "harmonic" sound.

Then just change the boxes and see if the missfiring follows to the other cylinder.

//Kjell