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Discussion Starter · #1 ·
Just registered here, as i have bought a set of 5JJ R1 carbs to go onto my kit car engine :) Can anyone tell me what year of bike these are off?

Im just interested to find out how reliable the carb's are, do they get the engine started well even in winter time? Im in the UK too, so winter temperature usually gets down to about -5c at most. But i assume most bike riders dont use their bikes during the colder months?

The reason im asking is im planning on doing a lot of trackdays, some of which will be in the colder months of the year, and i dont want to be spending ages trying to get the engine running...

So are they fairly reliable?, just using the choke system? I have previously used old Weber DCOE carbs, which did the job but were a nightmare to get the engine running(poorly designed choke system), so im hoping more modern R1 carbs will be better.

Thanks for reading.
 

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Hi 5jj is 2000-2001, I run my r1 all year round and dont have any problems with starting, usually never needs more than half choke 2 fire up in the middle of winter. hope this helps.
 

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Discussion Starter · #3 ·
Thanks for the reply.
In what way are they different from the other R1 carbs(4xv i think)
Is it just a different model engine?

Glad to hear they run fine even in winter :)
Thats exactly what i need.
 

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there both the same and just the new model code.

There are subtle differances but most parts are interchangeable.You can swap the cylinder heads complete with cams from one to the other but not the cams on their own as the oil feed is differant.
They should be totally reliable all year.Why did you not expect them to run during the winter?If your using it on the track and can't use antifreeze keep it drained to prevent freezing and only use distilled water.
 

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Discussion Starter · #6 ·
They should be totally reliable all year.Why did you not expect them to run during the winter?If your using it on the track and can't use antifreeze keep it drained to prevent freezing and only use distilled water.
Im used to using 30year old webers, having give them 10 throttle pumps before the engine will even fire etc, lol.
 

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M8. the guy is using them on a car and wants cold starting. Flatslides have no choke.

I am sure he wil get a good performance increase just using standard R1 carbs with appropriate jetting.

Head/camshaft lubrication versus models (4XV/5JJ) is irrelevant in this instance.

BTW Standard carb size is 40mm.
 

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My flatslides start fine in the cold.One twist of the throttle and it fires right up.They don't like ticking over hot or cold though.Have to keep blipping the throttle.
As for head,camshaft I was just letting him know that not everything is interchangeable.Perhaps I should let him find out the hard way??
 

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My flatslides start fine in the cold.One twist of the throttle and it fires right up.They don't like ticking over hot or cold though.Have to keep blipping the throttle.
As for head,camshaft I was just letting him know that not everything is interchangeable.Perhaps I should let him find out the hard way??
He is hardly likely to put an R1 head/camshafts on his car, he has already bought standard R1 carbs and also wants cold starting.

Flatslides may be an "upgrade" but also doesn't have a choke. I am sure he will be happy with standard R1 carbs and reassurance about cold starting.

Ask Marc.
 

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The Original One
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I assumed he had an R1 engine.If he doesn't I'm sure he can work out for himself wether to ignore my pathetic attempts at advice.
Flatslides set up well will start in the cold.
Perhaps you are right, I assumed he had bought the carbs for an existing non R1 engine. If it is and had later FI sounds like a backward step.

Also never heard of Webbers being fiited to an R1 engine.

Hopefully he will pick the bones from the posts.
 

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for thread starter :
yes , the carbs are pretty reliable .i dont know how it starts in cold weather , the coldest weather around here is 6 degrees celcius:)

sonicracingr1:
i'm using 01 R1 cams on my 99 head with no problem.
i did that swap intentionally because the newer cams hold oil inside them and this helps lubrication.
 

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yep, 98-01 carbs are the same. and the choke will help in cold starts. they are 40mm and imho a great choice for what you are doing. go for it.:thumbup
 

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THE MAN
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carbs work great. You will need to adjust the idle mixture screws to 3 or 3 1/2 turns out from lightly seated to get the best cold start out of them.

they are very reliable, and don't wear out quickly.
 

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for thread starter :
yes , the carbs are pretty reliable .i dont know how it starts in cold weather , the coldest weather around here is 6 degrees celcius:)

sonicracingr1:
i'm using 01 R1 cams on my 99 head with no problem.
i did that swap intentionally because the newer cams hold oil inside them and this helps lubrication.

That surprises me.A friend did that a few years back and the cams lasted 10 minutes.I know the oil is inside the cams but we worked out it was fed from the opposite end.Perhaps he did something else wrong then.My error.
 

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NeeD 4 SpeeD
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That surprises me.A friend did that a few years back and the cams lasted 10 minutes.I know the oil is inside the cams but we worked out it was fed from the opposite end.Perhaps he did something else wrong then.My error.
99-98 cams got no oil holes at all.your friend probably blocked the main oil passage to the head somehow.
 

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Discussion Starter · #20 · (Edited)
Right, cheers for the replies.

Sorry for the slight confusion,lol
And yeah, i dont have a R1 engine, its a 4pot 1600 16v engine.
Cool, 40mm is about what i want, and yeah the standard R1 carbs will be a great improvement over the restricted standard inlet system:)
 
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