Continued head gasket blowing?
 

I am now due to leave for the sahara in 12 weeks. I started work on my bike six months ago, this included a head rebuild ( valves, seats, head skim, rebore, new piston, rings, etc. ). I had the work done by a local engineering company/ bike mechanics due to a lack of time to complete the job myself.

The job was initially prompted by a low compression reading, and after the job was completed I ran the bike in as specified in the manual. I did the running in a single long ride. On returning home the head gasket was blowing.

I returned the bike to the workshop and it was opened up again. I was told that despite no initial problems with the torque settings 3 of the head bolts had pulled their treads and required inserts. I was also quizzed as to why all the rocker box bolts were so tight? ( I believe 7 ft/lbs is normal, the mechanis had to crack them off with a 2ft breaker bar) I obviously has no idea!

I paid for a new set of top end gaskets and three thread inserts. I was told that they excepted no responsibility for the problems but would reduce the cost of the hourly fee as a 'good will gesture'.

On return of my bike I have now completed 15 miles and have an identical problem. The head gasket is blowing and I also have seepage through my base gasket.

Does anyone have any suggestions why this should happen? I had the head skimmed to avoid any problems with warping and the engine obviously compression tests fine until you ride it above 5000 revs at which point all my problems start again!

I am now pretty screwed, I am running out of funds, can't really afford to get work done elsewhere and seem to be tied to a nightmare repair workshop....

HELP!!

in my opinion you shouldn't have paid something for the second repair.
if something like this happens to an overhauled engine, obviously the work was not performed in a good manner.
what type of inserts did they use? helicoil (or permacoil or amicoil etc.) is no good at this place!
here you can see some pics of how it can be done: http://www.xt-foren.de/dcforum/DCForumID6/29.html#

and why they repaired only 3 threads, why not all? it's not this much work and then you are on the save side.

regards
klaus

Hi.
This is one of the most common early xt problems.
Helicoiling the standard threads NEVER NEVER NEVER works.
I wont bore you with the reasons why.
The only way round this problem is to use two double length inserts ( of the helicoil or recoil type ) and longer head bolts. Unfortunately as you have already had inserts pull out and damage the ( now larger diameter ) thread, you would have to go up a size to M9 orM10 inserts and for these there is not enough room.
Yamaha realised this as a problem and for a while the 34k 03 type cylinder was available as a kit with longer bolts and longer threads to take them. Guess what! two years ago this part was deleted.
There are some other rather dubious ways of sorting this problem but really you need a modified 34k,34k01,34k02 cylinder or a good 34k03 standard one OR I can supply a later type cylinder modified to fit the early type top end.
Let me know if you need further help.
D L

David,

Arse.....

It seems that things arn't going my way!

Could you please advise me on a number of options.

1) What is the best advisable fix for the job bearing in mind I have just rebuild my head and as far as I am aware it is as near perfect as it can be ( new valves, springs, reground seats etc)( i.e. tell me my head can stay!) . Also I understand that later cylinders had larger cooling fins to compensate for 1vj cooling problems, would a part supplied by you be of the later type, or similar to mine?

2) What would the cost for the parts for this job be if replacement parts were essential? you talk of being able to supply parts....at what cost? and how quick!!!

3) I do not have the time to attatch the parts myself and the shop I took my bike to now has it back! They are attempting to fix the job again. Obviously I now know that their fix it job won't work! ( And I wish I'd brought it to you in the first place!) However, they are liable for this mess and so would it be ok to get them to contact you to either,

i. Carry out the work at their expense.
ii. Liase with you to supply parts.

If so could you mail me with your details so that I can give you a ring?

Many Thanks for your time


Dave Lomax