Rebuilt the engine!

[MLGTIB]

Hey everybody. So I have an 05 GZ with about 6100 miles on it. Since I bought it in September, I noticed that every time I started it up it would make this popping sound. I recently took it to the dealer to replace the brakes and the mechanic noticed it to. When I went to pick the bike up he informed me that on the front of the engine there was a nut missing and the stud was just hanging freely. So I ordered up a whole bunch of parts and got to work. I replaced the head gaskets, all the studs, and Piston rings since I was already in the engine. I finished all the repairs yesterday and when I started her up it was beautiful, not a single noise other than the engine running of course. It sounds like a new bike. In order to remedy this problem from happening again I just added some locktite to all the studs. I rode it for about 50 miles and am very happy with the results. Once I have a chance to upload a short video of the first start up I will. :2tup:

[alanmcorcoran]

I think a lot of the mechanical types on here will be looking forward to seeing your movie.

Did you order the parts from Suzuki or somewhere else?

[Easy Rider]

When I went to pick the bike up he informed me that on the front of the engine there was a nut missing and the stud was just hanging freely.

I'm really glad that all turned out OK but........
It is highly unlikely that ALL THAT needed to be done on a bike with that kind of mileage. I suspect that you have more mechanical skill and experience than about 99% of the people here and a "do it yourself" rebuild of that magnitude would probably NOT be a wise undertaking for most.

Just exactly what WAS the part that was loose ??
Could you not have just fixed THAT without doing all the rest ??

[burkbuilds]

It does sound like a lot at first read, but when I went back and read the original post again it looks like the only thing you did that was probably unnecessary was the new rings. I guess if you've got the engine out and all, popping a set of rings in isn't really a big deal on a one cylinder engine, and with no more mileage than you had on it, you probably didn't even need to hone the cylinder. Otherwise just gaskets, studs and nuts.

[MLGTIB]

The cylinder head nut that was missing was the one just below the two exhaust ports on the front of the engine. In addition, the actual stud that it screws on to had come lose and was resting on the cylinder base below it (it doesn't fall out and get lost, but falls out and remains loose in its bore), and that created the leak in the head, which creates the popping noise on initial startup. After heating up, that usually goes away since the engine expands with the heat and seals the gap well enough. Since I had to remove so much of the cylinder head it required me to replace all the gaskets. Although I didn't HAVE to replace the rings or cylinder base gasket, I figured I might as well for my own peace of mind. As for experience, I have a bit but I have never done anything to this extent. I used the service manual which has good instructions. The only thing that I recommend is to download the word doc version because in the section that explains how to install the new piston rings there is a picture that is on top of a diagram that shows you how the gaps of the rings should be positioned.

The dealer wanted $400 to do the job, where I did it for the cost of the parts which came out to be around $75. If you are a person who wants to learn more about how the engine works and how to do the repairs yourself than this is the engine to do it on. It was pretty easy to do, just have to have a little patience and go slow to make sure you get it right. Best of luck to all that jump in on the engine repairs. :2tup:

[Maggie]

Hey MLGTIB! Looks like we're neighbors...I'm in West Van Nuys (basically Reseda!). I am totally inexperienced with any kind of mechanical work, but really want to start doing the work. Maybe next time you do dome basic work on your GZ I could bring mine over and watch you? Then maybe I'll get the courage to try something like an oil change (I love reading the "how to" posts, especially with the pics!)

[MLGTIB]

Hey MLGTIB! Looks like we're neighbors...I'm in West Van Nuys (basically Reseda!). I am totally inexperienced with any kind of mechanical work, but really want to start doing the work. Maybe next time you do dome basic work on your GZ I could bring mine over and watch you? Then maybe I'll get the courage to try something like an oil change (I love reading the "how to" posts, especially with the pics!)

Hey Maggie, I will try to keep you in mind when I need to do something. Oil changes are the easiest thing to to. When its time just let me know. On a side note, I am always looking for someone to ride with. Hit me up anytime. I will get the pixs and video up later today for everyone to see. :rawk:

[trykemike]

Hey MT !

When I had put 1000km on my bike i examined the engine and noticed what appeared like an oil sweat between the exhaust pipes at the gasket . I also tightened the nut that is there between the pipes and used blue locktite. That resolved the oil leak. There is a similiar nut under the carb at the back of the head snug it up also. Check the manual for a detailed picture.

[MLGTIB]

Here is the video of the First Start up. Please excuse the poor quality, I used my iPhone to record it.

http://i705.photobucket.com/albums/ww59/mlgtib/th_FirstStartupafterrebuild.jpg (http://s705.photobucket.com/albums/ww59/mlgtib/?action=view&current=FirstStartupafterrebuild.flv)

[alanmcorcoran]

Pretty good quality for iphone!

[Water Warrior 2]

Sounds like a sucessful rebuild.

[MLGTIB]

It definitely was. Now I am thinking of adding the 16t sprocket, but i am not sure. I am worried that the engine will rev to high. What do you guys and girls think I should do. :??:

[Water Warrior 2]

It definitely was. Now I am thinking of adding the 16t sprocket, but i am not sure. I am worried that the engine will rev to high. What do you guys and girls think I should do. :??:
Going from a 15 to a 16 tooth front sprocket will reduce the rpm.

[MLGTIB]

So if i am understanding this correctly, it will reduce the rpms and increase my speed capability.

[patrick_777]

It will lower the top end speed slightly too.

[Easy Rider]

So if i am understanding this correctly, it will reduce the rpms and increase my speed capability.

Theoretically except........the little 250 runs out of raw housepower when the wind resistance gets to high so you typically loose a little top end in 5th gear. With the rebuild you have done, it might not be as noticeable to you as it is for most.

The real advantage is in the lower gears where you WILL gain some speed and can stay in each gear a bit longer. If you encounter a situation where it won't pull in 5th gear, it will do ~50 in 4th for short stretches.

[MLGTIB]

if that is the case then I think i am just going to leave it alone. I thought that I would get a bit more speed overall. Thanks for the clarifications guys. Happy riding to all.

[Easy Rider]

if that is the case then I think i am just going to leave it alone. I thought that I would get a bit more speed overall. Thanks for the clarifications guys. Happy riding to all.

If you do much freeway riding, that's probably a good decision......BUT.....

A LOT of us have been amazed at the better feel and it only costs about $16 and takes about a half hour to change out, including a minor chain adjustment.

If you don't get on the freeways much, I highly recommend that you try it. With your mechanical skills, it should be a breeze to change back.

[MLGTIB]

I have never taken it on the freeways. I am more of a street and canyon rider. I guess it wouldn't hurt to try it and see how it feels. Which one would be the best to get and from where?

[Easy Rider]

Which one would be the best to get and from where?

A sprocket is a sprocket. I got mine through the dealer; about $16 and 3-day delivery, steel.
For that price, I didn't even look around. I think they charged me 1/2 labor to install it; about $35.

The replacements don't have the rubber shock section but if you don't speed-shift, you shouldn't even notice that.

[MLGTIB]

A sprocket is a sprocket. I got mine through the dealer; about $16 and 3-day delivery, steel.
For that price, I didn't even look around. I think they charged me 1/2 labor to install it; about $35.

The replacements don't have the rubber shock section but if you don't speed-shift, you shouldn't even notice that.


I will go to the dealer and find out. Thanks for the info Easy. :2tup:

[SlyFinkley]

MLGTIB,

Thanks for the confidence boost.
I have re-built a few car motors before, but the bike is a bit foreign to me.
Now I will gladly grab the toolkit & have a go. ( Even if I need to post here, or call in a favour to finish the job.)
:techy:

[oneyunguy]

I rebuilt my engine too, but I do have 32,000 kms. I did it over a winter. I did some work to the cylinder and oversized it a 'lil. Then put a new piston and rings and all new gaskets all around. It was fun and rewarding at the same time. I was thankfull to have a garage at that time. I couldn't wait for good weather to go riding again after it was all back together. At the same time I put together some bars with blue led's in them and installed them on the frame pointing to the engine.

[emory70]

buddy of mine is a former race car builder/driver. a number of years ago, he bought a brand new sportster with the intention of customizing it. he took it home and tore it down to the last nut and bolt. cleaned it up and put it back together (as he put it), with his customizing touches and paint. when he took it to the dealer to sell it on consignment, the guy at the dealership took it for a ride, and said it was the fastest 883 he'd ever ridden, and wanted to know what my buddy had done to it. he just shrugged. in capable hands, even a brand new machine can use a little love.

[GTGZ]

Although I didn't HAVE to replace the rings or cylinder base gasket, I figured I might as well for my own peace of mind.

Anytime you remove the cylinder head you should always replace the base gasket or you will have a oil leak, don't ask me how I know.

[GTGZ]

If you ignore the popping sound and keep running the engine you could end up with a cracked cylinder head, don't ask me how I know.

http://s207.photobucket.com/albums/bb55 ... yl%20Head/ (http://s207.photobucket.com/albums/bb55/stroknsmokngt/GZ250%20Cracked%20Cyl%20Head/)

[Canuck]

I recently posted the same problem... sucks to know ill have to rebuild to remedy but...oh well

[Easy Rider]

I recently posted the same problem... sucks to know ill have to rebuild to remedy but...oh well

Wait a sec.
That's not exactly what he said.
He said if you ignore it, and don't fix it, it COULD end up with a major repair.

At this point, I don't think you know if your situation is the same as his or not.

Further, replacing the cylinder head is not often referred to as "rebuilding" the engine.

Jumping to conclusions can often lead to undesirable results.

[Canuck]

Hey everybody. So I have an 05 GZ with about 6100 miles on it. Since I bought it in September, I noticed that every time I started it up it would make this popping sound. I recently took it to the dealer to replace the brakes and the mechanic noticed it to. When I went to pick the bike up he informed me that on the front of the engine there was a nut missing and the stud was just hanging freely. So I ordered up a whole bunch of parts and got to work. I replaced the head gaskets, all the studs, and Piston rings since I was already in the engine. I finished all the repairs yesterday and when I started her up it was beautiful, not a single noise other than the engine running of course. It sounds like a new bike. In order to remedy this problem from happening again I just added some locktite to all the studs. I rode it for about 50 miles and am very happy with the results. Once I have a chance to upload a short video of the first start up I will. :2tup:



that is the same thing that i have ... a loose or stripped stud hanging down and against the bottom half of the engine..

the only way to fix this is to take the engine apart... there is no way to get loctite in and effectively re-install a stud/nut, unless the top block of the engine is dismantled.

what a shitty thing to have happen... without the expertise to take apart the engine etc...im up shit creek without a paddle..

[Canuck]

I'm pretty fortunate for this post.

To have someone describe EXACTLY the same situation I'm in is pretty lucky.

Takes alot of potential expensive guess work out of it.


Currently the bike still has a hanging stud/nut under the two exhaust pipes. Makes a loud POP upon startup, and goes away after being ridden awhile. However when taking off in first gear it definetely "snap crackle and pop's" until it reaches about 15-20 km/h then it sound normal.

In the future im hoping to do the same as this post. new gaskets new stud/nut etc

thanks again for this post!

[Water Warrior 2]

Remember, you heard it here first. :2tup:

[Canuck]

Hey Water Ill be in squamish in less than a week maybe ill see ya bootin around town?

what are you riding again ill make sure i wave ! hahah

[Water Warrior 2]

Hey Water Ill be in squamish in less than a week maybe ill see ya bootin around town?

what are you riding again ill make sure i wave ! hahah
Fat blue mule. AKA a Vstrom 650 with all sorts of ugly stuff on it. Wide enough to be a small car and just dirty enough no one will steal it.
Stop in at the Local Starbucks, always some one there to meet.
http://s4.postimage.org/qhvCA.jpg (http://postimage.org/image/1hcvtoqxw/)