Backfire on Honda Deauville

Crapbag

I just bought a Deauville from Wales. Great condition with low mileage. Yet it seems to backfire quite regularly when I drop a gear. Im thinking its an ignition timing problem. Has anyone had any experience with this before?

Any assistance would be great..

sutty

I have it on my S4r. Its a fuelling problem on mine. Due to a change in the exhaust system and an open air box. With out the fuel map been correctly changed. Is there an after market can on the bike? Is it ECU or Crab?


EDIT: Spelling mistake

Idleater

I get it on my new bike too.

When the fueling is properly matched to the exhaust system, you will get this because when you shut off the throttle there is unspent fuel going through the system which pops in the exhaust canister. You can see this on the motoGP / SBK bikes, complete with flames.

Of course the fuel needs air mixed with it to pop, so you probably have a slight leak in the exhaust system. Check for a proper seal where the end can attaches to the exhaust pipework. Also check where the exhaust headers attach to the cylinder heads.

Fr Dougal

Crapbag wrote:

I just bought a Deauville from Wales. Great condition with low mileage. Yet it seems to backfire quite regularly when I drop a gear. Im thinking its an ignition timing problem. Has anyone had any experience with this before?

Any assistance would be great..

I'm also on a Deauville since July and have the same problem. Left it in to M&A for full service and they told me it is a "Feature" of the Deauville when changing down, something due to Exhaust design. Still happens after the full service. A slight change of riding pattern / gear change / throttle use has minimised it.

Go to www.deauvilleuk.org online owners forum and you'll find it's a very common problem with the Deauville (You have to register on the site to access the maintenance forum)> Tell them Fr D sent ya.

Crapbag

Its a standard honda pipe. Not changed and no mods. So What did you do to reduce it? Ive avoided down shifting from the higher rev range and its limited it somewhat but its still an unpleasent sound and wouldnt like it to affect my riding or scare other road users.

faceman

i used to the odd time get this on my deauville (when i had one:() although i didnt really notice it changing down gear. Funnily enough, i never got it if i had filled her up with that shell v-power petrol!

Crapbag

Here is another thing I found strange. The panyard boxes seem to be quite difficult to close properly. If the small clips on the sides arent down fully,the boxes will open and if you put too much luggage in that will cause any pressure on them, they open. Is this another undocumented feature of the Deauville? Anyone have any problems with these panyard boxes?

faceman

the boxes prob just need to be adjusted. Have you the manual? it says how to do it in it. An even easier way it to adjust the clips afaik.

I also recommend this website. Its based in the uk but they have plenty of irish members. They did a run over here during the summer too. THey're very helpful.

http://www.deauvilleuk.org/forum/

Fr Dougal

Crapbag wrote: »

Here is another thing I found strange. The panyard boxes seem to be quite difficult to close properly. If the small clips on the sides arent down fully,the boxes will open and if you put too much luggage in that will cause any pressure on them, they open. Is this another undocumented feature of the Deauville? Anyone have any problems with these panyard boxes?

Yep, had similar problem, very easy to rectify. The metal loops on the pannier lid have to be adjusted. Simply loosten the two screws holding the loops. Move them out 1mm. Tighten screws and test. If you still have problem, repeat with another 1mm adjustment. Repeat until you get it closing correctly. Don't go 3-4mm from the start as this would fix your problem but lids may be a bit loose, not sealed.

Re changing driving pattern to minimise backfire / popping, it's very hard to describe, you get to know when it happens and then just keep the revs slightly higher when changing down in the higher gears.

gok

I bought a new Deauville 700 in April and just a month ago had probs with one of the panniers, on eof the metal hoops wasn't clicking in. I could tell it was a problem with the spring but because it was still under garauntee, I brought it back and the shop fixed it by ordering a complete new piece.
Never had the backfire issue though - only ever had that when I push started a GS500 - sounded like I was being shot:D

Crapbag

Just to finish this up. I went up to Bikeworld with it. There is a good guy there from the parts section who identified the problem as the down pipe. He could instantly tell there was air being sucked in. The solution is to replace the gasket/spacer and one of the clamps. One thing I never noticed that he did was the heat scoring on the down pipe. Just in case it happens to anyone else