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Engine getting very hot.

2K views 9 replies 6 participants last post by  OlHossCanada 
#1 ·
Hi All,

I'm having some issues with my engine heating up.
The temperature seems totally normal but I feel too much heat on my left leg. Too much to be normal.

To add some details.
I just finished rebuilding the carbs and the engine. On top of that, I've changed the stator coil too.
There is new engine oil in there and I'm using my ol' trusty coolant in the radiator.

I just took the bike back from the mechanic yesterday and rode to work and back and it was OK.
Today I was riding to work and mid way I noticed the engine feels very hot on the left side. The engine heated to the point that it couldn't idle and would die out. (All this while the temperature was showing normal)

The whole engine job was done by an old friend of mine known to be the best Kawi mechanic in whole Malaysia. He has done all my other bikes and so far no issues. So I'm inclined toward believing that he has not screwed up anything.

The issue was not present before I rebuild the engine so I don't know what the problme could be.

I would appreciate all the insights and I'm looking forward to some gurus stepping in and enlightening me with their thoughts.

Thanks a bunch.
 
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#2 ·
Sorry your going through this but I would also ask your excellent mechanic. I am sure people will chime in soon.
 
#3 · (Edited)
I'm going to him right after work. But the thing is he does not believe in mods. No matter how you try to convince him, he will always tell you to keep the bike stock and not mess with anything.

But people around have done it all, tried different things and certainly know a lot about such stuff. Some like Lance have been with their 7XX for long enough to know her like a member of family.

Moreover, the whole thing happened on the way to work and I'm still at work now. So it would be great if I can find something out before I leave the office. This site has always been of great help to me; There are a couple of thousands of people registered here and I'm sure someone, somewhere has gone through what I got here. I would absolutely love to hear how they have overcome the problem.
 
#4 ·
When you say you are using your ol' trusty coolant, do you mean you didn't put fresh in, or that you used the same type you've always used? Any possibility it needs changing? Could something be blocking one of the coolant channels on that side of the bike?
 
#5 ·
Hey buddy, it's been sometime since we last chatted. Well I peed inside the radiator as I always do. hahahaha. That was a lousy one I know.

I put in fresh coolant. The very same type I have always been using on this bile before the engine rebuilt and on my all other bikes. It has proven to work best in Malaysia's weather. And while rebuilding the engine, I've flushed the radiator and all the channels. So I guess we are good there.
I personally am inclined toward thinking that the timing of the valves on the rear cylinder to be set a bit too tight. What do you think?
 
#7 ·
I just finished rebuilding the carbs and the engine.
Always great to have a master mechanic around.
On engine rebuilds, it is always important to note the coolant ports in the new gasket sets. Gotta make sure the correct holes have been punched in the new set. I know there is no way to tell now that the bike is back together, but you may tickle the brain of you mechanic to make sure he /she specifically checked that.

Good Luck.
 
#8 ·
I am no expert, but the first thought that came to mind when you said it is only one cylinder that seems to be too hot was that the fuel mixture is too lean.

Are you getting any popping or backfiring from that cylinder.
Need to remove the plug and turn the screw out richer maybe??
 
#9 ·
Thanks Gordon for the input. I thought of that myself too. But was more inclined toward the tight timing as there is hardly any backfiring. What do you think?


Sorry, I'm not a guru. 'presently looking at manual (Overheating) and the book gives lots of reasons. I'm trying to narrow down based on the above:

Carbs: fuel/air mixture incorrect? fuel lvl/float too low? Carb holders loose? double check the ducts and holders.
Firing incorrect: plugs dirty, broken, incorrect? basically checking plugs/all the wiring/connections/opened ends grounding out?
Lubrication: Oil lvl too low/poor quality or incorrect? but I can't see any of the lubricants being the case as you claim it to be just one cylinder to cause issue?

Of all the reasons stated here, I've only listed what "I" believe to affect just one cyl. Of course, it could be none of the above. I am not well versed in this. Sorry. When I develop an issue, I research past threads on this site. Ride safe.
Thanks a big bunch mate. I really appreciate your help. I think I'm gonna check on the plugs too. Since the engine was lubed before putting together, the excessive lube could have made the plugs going off too quick. It's not very likely but well it ain't impossible either. So I'll check on them too. Thanks again. ;)

I appreciate all your inputs and I'm looking forward to more thoughts from you guys. Thanks a bunch.
 
#10 ·
After re-reading this whole thread, I am unclear whether you have had the engine apart or just had the carbs pulled off.

I also do not understand what you you mean by "tight timing".
The timing cannot be adjusted on the vn, it is electronically controled.

There are only 2 things that could affect the valve timing that I can think of.
First is if the engine has been apart and the timing chain and gears not aligned properly when reinstalled.
Second is if the timing chain is so worn that it has jumped a cog on the timing gear.
 
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