PDA

View Full Version : 400 ex Tappet Cover Bolt #7 Breaking



hapychap
06-08-2004, 03:51 AM
[COLOR=crimson]:grr:

Greetings all. There was a string a short while back regarding this issue and I cannot find it so I will start again.

:confused: There are 5 of us here in these hot parts of the planet riding the 400ex. All 5 of us have the same problem. The #7 TPT cover bolt is either broken or very loose. (Right Front bolt) just above the exhaust pipe.

A few posts had mentioned the same problem and even some solutions. However on 3 of the bikes there is also an oil "weeping" :eek2: directly below the bolt between the head and the barrel and we are wondering if it could be related?

None of the bikes have had any engine work done to them and the only mods are exhaust, filters and gearing. All maintenace has been done by the Honda dealer and we have pushed him to check with Honda if it is a known problem and if there is a fix/solution to it?

During a service would it be neccessary to loosen this/these bolts? For the rocker clearence adjustment there are seperate 'caps' to make the adjustment/setting?

Anyway, we just want to present a reasonable case with "global" evidence as at this stage it could also be refered or pointed back to the dealer mechanic.

One of the guys also seems to remember reading a while back on a forum, not sure if it was this one, that there is a bolt on the Bike which is often a cause of contention as there is an error in the workshop manual in that the manual gives an incorrect torque setting which is to high often relating in failure. Not sure if this is the bolt in question.

Would appreciate all feedback and confirmations of similar situation in other parts of the world.

:( Thanks

2003400exmnymds
06-08-2004, 04:40 AM
I removed my head cover and on re-installation, I broke the #7 bolt and the #5. I can honestly say that the bolt was way too long for the head, how it wasnt too long before I messed with it is beyond me. Anyway there is a forum on this site where everyone was complaining about the bolt snapping with little torque added. I know what you mean about the dealer thing but just didnt want you to stand alone. I put some sealant around the shaft of the 2 broken bolts and put them where they belong (pretty much glued them in place) Im hoping for the best she hasnt leaked yet.

hapychap
06-08-2004, 05:24 AM
;) Thanks.

tell me, how does your Big Gun CDi perform? You happy with it? You recomend it?

I hope others will reply to the bolt issue. I know a buddy started a string a while back but it has "mysteriously" vanished?? Is there a conspiracy brewing? Does Big Brother Honda have access to remove "undesireable" 'advertising'? :huh

2003400exmnymds
06-08-2004, 09:31 AM
Honestly thats one thing that was done when I bought it so I couldnt tell you the difference between the stock one and the BIG GUNS. I can tell you one thing I Love the exhaust. Best thing since sliced bread..........

I dont know what happened to the thread but I read and replied to it also, maybe HONDA did have something to do with it.....HMMMM.........:confused:

mikeminyard
06-08-2004, 11:06 AM
To fix your problem go to a hardwear shop and buy, I think it is an M6 bolt in 120 mm length. I got the black bolts because they are much stronger. Then take 2 1mm thick washers and put these between the bolt and the cover. I ended up replacing all of the bolts in this manner because those stock bolts are very very weak. The reason that they are too long by the way is because they are such weak metal, they stretch when torqued and become too long.

hapychap
06-08-2004, 11:12 PM
Originally posted by mikeminyard
To fix your problem go to a hardwear shop and buy, I think it is an M6 bolt in 120 mm length. I got the black bolts because they are much stronger. Then take 2 1mm thick washers and put these between the bolt and the cover. I ended up replacing all of the bolts in this manner because those stock bolts are very very weak. The reason that they are too long by the way is because they are such weak metal, they stretch when torqued and become too long.

Sure, makes perfect sense, but why is Honda not doing anything about it? Sounds to me like we are not an isolated incedent? Of 6 riders with 400ex's, 5 have the problem. If it is as simple as replacing it with a higher tensile bolt why has Honda not done so? Unless the higher tensile bolt will put additional stress on the aluminium components that they cannot withstand? Do you think our extreme heat conditions also come into play?

hapychap
06-13-2004, 02:41 AM
:( :( Anyone else have something to add please? :( :(