Transalp 400 won't rev past 6500-7000rpm (100kph)

[Arctic Alp]

Hi everyone,
I just bought a '93 Transalp 400 (Jap import) and have found that it won't rev past 6500-7000rpm which is about 100kph. It feels like a govenor is on the bike. The carb's have been tuned etc, but someone told me it may be the CDI's, although the tacho works and there is no misfiring. It has MS8 CI 558's, but it also has smaller numbers below these, just wondering if anyone knows of this issue, or if they know if these numbers are normal. Numbers are 3.6 031 Front, 3.6 161 Rear.

Thanks

[StumpyFingers]

Have the inlet rubbers been restricted?
How clean is the Air Filter?

[Arctic Alp]

Hi Stumpy Fingers, the aircleaner is brand new, not sure about the inlet rubbers though. If it was the inlet rubbers, would that also reduce overall power, or just at higher revs?

Thanks

[StumpyFingers]

The fact that it is not revving past 6500 -7000 rpm means it is restricted, one of the ways this was achieved was by reducing the throat of the inlet rubbers thereby reducing the mixture entering the engine.
If you can find some get hold of a set of rubbers from a 600 (same engine).

[dal]

I more or less had the same problem recently with my XL400v.
Thought I needed the carbs tuned but turns out it was the air filter.

A while ago, I decided the filter needed changing and I ordered a XL600v filter from wemoto [thinking it would do the job] because most part suppliers don't list the XL400 . Anyway, wrong. Too much air being let in and performance went the same way as you describe.
I put the old one back in and now it's fine.
My dealer has ordered a new one directly from Honda; but it's not cheap @ approx. €40.

[Arctic Alp]

Hi gents, thanks for the replies..

Stumpy Fingers..I will check the inlet rubbers for sure..Does anyone have the inner diameter dimensions for the 600 inlet rubbers, just so I can verify if there is a size difference in mine so I don't just buy them and find out they are the same size.

As for the air cleaner, which is new, but I bought it from a Honda dealer here in Norway, but I don't know if it was a genuine Honda product. What's the opinion on using K n N filters?

Thanks again

[dal]

Hi gents, thanks for the replies..

As for the air cleaner, which is new, but I bought it from a Honda dealer here in Norway, but I don't know if it was a genuine Honda product. What's the opinion on using K n N filters?

Thanks again

Take a look at the filters here....
I bought the one at €13 and the K&N filter is €80! Must be good.
I've wasted €13 but the K&N is still probably the wrong size for the 400 (from here anyway). You may, of course, have the correct one.

Take a look at the one priced at €13. Note how the opening to the inside of the filter is completely open. The old one on my 400 (the one that works) is NOT completely open. It's covered by a metal plate containing a hole only about 1.5 - 2.0 inches in diameter to the inside of the filter.

[Arctic Alp]

Hey Dal,
That's very interesting regarding the air filter. I will check what's in my bike, hopefully it may help towards the problem.
When you said you had to order a special one for your 400, did the dealer say that the 400's have this "end plate" especially, or is this for all Transalps?

[dal]

Hey Dal,
That's very interesting regarding the air filter. I will check what's in my bike, hopefully it may help towards the problem.
When you said you had to order a special one for your 400, did the dealer say that the 400's have this "end plate" especially, or is this for all Transalps?

The mechanic told me, yes, it seems this filter is particular for the 400. This dealer imports and sells the 400 on a regular basis and he's lost count the amount of times owners have fitted filters designed for the 600 and then ran into problems.

[dal]

Looks like this...