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Seized MC21


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Harryredchow

 
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Seized MC21

Sun Nov 07, 2010 5:30 pm » Post: #1 » Download Post

So after putting new Tyga pipes on my bike and a set of nice new tyres, I set off for the ace cafe only to have the bike seize on me. It is absolutely stuck solid and will not turn at all. I rather foolishly tried to kick it over and it moved a tiny bit before getting stuck fast.

The problem I have is getting to the route cause. It doesn't run hot and there is a nice layer of oil in the pipes. I had it on a dyno recently and it was running slightly rich at the top end (before the new pipes), so I don't think it is running lean. One thing I have noticed is that the battery was nearly dead after it had stopped. Could a failing battery have caused the issue? Fueling/Ignition may be aaffected by this??

Next step is a full top end rebuild. Do these engines typically destroy the bores, or is it likely to be just pistons?

Any advice on a top end rebuild would be most welcome. Tips, people to repair bores, replates, etc etc. I am a bit gutte at the moment and could do with some support from my NSR bretheren Sad

Thanks.
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Andy
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Sun Nov 07, 2010 5:53 pm » Post: #2 » Download Post

Hmm... you didn't rejet with the new pipes?
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Last edited by Andy on Sun Nov 07, 2010 5:59 pm; edited 2 times in total
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StephenRC45
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Sun Nov 07, 2010 5:53 pm » Post: #3 » Download Post

Asumption is the mother of all **** ups!

Slinging a set of pipes on has just cost you a good few hundred quid in a new barrel/replate plus piston etc.

We say it time and time again. Check your jetting after every modification.
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Neal

 
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Sun Nov 07, 2010 5:54 pm » Post: #4 » Download Post

When you strip the top end you should get a beter idea of what may have been the cause . We normaly change jet sizes when we change pipes .
How were you riding - flat out on the highway or just plodding along in traffic ?
I don't think that the battery would have contributed to your seize .
Post up some pics and we can see from there .
Show us your barrel too , maybe you can clean it up

Maybe Tyga could include some instructions with their pipe sales Question Idea
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Andy
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Sun Nov 07, 2010 6:00 pm » Post: #5 » Download Post

Neal wrote:
Maybe Tyga could include some instructions with their pipe sales


Ethos sent me new jets with my pipes! Very Happy
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silikesguiness
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Sun Nov 07, 2010 6:05 pm » Post: #6 » Download Post

unlucky mate,but as said its always worth a rejet after swapping parts,how fast were you going? it could make a difference on cylinder damage,chin up mate weve all had an engine misshap at some point.......or 3 Laughing not the nsr i might add,it was that bloody tzr of mine Laughing
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Andy
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Sun Nov 07, 2010 6:07 pm » Post: #7 » Download Post

Has your NSR ever run Si? Kind of hard to seize yours when it's not seen a drop of mix for 2 years! Laughing

TYGA does say this on their site:

"Pay careful attention to the jetting at all times. If in doubt, start rich and lean off as necessary."
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Harryredchow

 
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Sun Nov 07, 2010 6:08 pm » Post: #8 » Download Post

Thanks for the comments guys. I did suspect that the pipes could have had an impact. Top end rebuild and new battery are on my list of things to do. I had it on the dyno only the other week as a health check. If the Ace Cafe meet hadn't come up, I would have drilled the airbox and taken it back for a rejet on the dyno.

You live and learn I suppose. Maybe it was the pipe, maybe it was just it's time. Whatever, it still leaves me with a top end rebuild to get done.
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Andy
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Sun Nov 07, 2010 6:13 pm » Post: #9 » Download Post

Whip the pipes off and have a look up the ports. Probably only one that's gone (50p usually on the front!) and then pull the cylinder off.

Many times they will clean up if you catch the clutch in time. The Nicosil is pretty hard. Probably wasted the head though.
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Harryredchow

 
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Sun Nov 07, 2010 6:18 pm » Post: #10 » Download Post

Wasted the head? Is that normal? I can understand the rings and piston, but not the head. I will try and get it into my brothers garage this week and pull the thing apart.
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silikesguiness
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Sun Nov 07, 2010 6:31 pm » Post: #11 » Download Post

andy you cheeky sod Laughing when my nsr decided to give up it did both cylinders and heads,but then it was flat out in sixth down a hill at the time Rolling Eyes pretty cool sideways when it seized at that speed as well Laughing
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Neal

 
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Sun Nov 07, 2010 7:44 pm » Post: #12 » Download Post

you can clean the heads up if they are damaged . Sometimes there is a transfer of ally from the piston to the head .

Get a 300 and be done with your mods !
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Andy
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Sun Nov 07, 2010 8:05 pm » Post: #13 » Download Post

ROTFLMAO

That's the best one I've heard for years!

Step into the light, Neal! Laughing
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Hermit

 
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Mon Nov 08, 2010 4:11 am » Post: #14 » Download Post

Neal wrote:Get a 300 and be done with your mods !


Agreed, the 300 kit will give you a pair of brand new Honda nikasil bores and brand new heads with central spark plug on the front head. You'll be starting with a fresh top end AND it'll be faster!

I'd sooner trust an original Honda plated bore than a refurbished one done by a local firm too.

If aluminium swarf has been drawn throughout the engine you'll want to make sure there's none sitting in the main bearings on the crank as this will cause further disaster down the line if left un checked. You won't know what you're faced with until you pull the top end to bits.

Bad luck mate, hope you get it fixed without too much drama.
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Harryredchow

 
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Mon Nov 08, 2010 9:18 am » Post: #15 » Download Post

Thanks again for the comments. I shall pull it to bits and see what the damage is. I was doing about 70mph at the time and stopped in about 500 yards. Initially there was some movement when I kicked it, but it got stuck, so my thoughts are that I may have been lucky and it has not wrecked anything too badly.

As much as I would love the 300cc kit, it is just way to expensive. I reckon with a replate and top end rebuild I can do the repair for a few hundred quid, so £1200 for the 300cc kit seems a bit excessive. The more I think about the bike the mor i believe it was on it's way out anyway. I took it to the dyno because it was bit wooley at the top end and they found the fueling to be fine and no ignition issues. The bottom cylinder leaked a bit of coolant from the base gasket as well, so maybe it has had a few issues. Seems a bit of a coincidence that the pipes had changed as well, but I had only covered 2-3 miles since changing them.

I will continue to request your help, as these engines are pretty new to me.
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