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mikeythefokker

Performance Engine Mods and E start

31 posts in this topic

I am going to be getting into the engine of my 07 wr450, and If I'm going to do any little hop ups, now is the time. I'm curious about how yz cams work with e start, how hot cams work with the e start, and how higher compression pistons work with the e start. I am in no way willing to part with my magic button. I love it. Ideally I want a bike that grunts like a wr down low, but will rev out well like a yz. I'm not really looking for a ton more power, or a setup that is too finicky. I love the reliability of my bike and don't want to sacrifice too much of the durability of the stock setup. Let me know what has worked for you guys and what hasn't. Thanks.

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I put HotCams in my 04 last year, and no e-start issues at all.

I added a FMF Ti PowerCore at same time, and big power gains, especially in mid and top without loosing the "chug" factor. It did give it a pretty substantial "hit" in the middle though, which personally I love, but if your a hardcore technical kind of rider, you may not.

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Like you I have an 07 that's in need of a piston replacement so I figured I would try a couple mods. I got a 13.5-1 HC piston and a set of YZ cams. I plan on doing the rebuild here in a couple weeks.

From what I've found researching the e-start should work with the piston and intake cam and might work with the piston and both cams.

I purchased some slightly used YZ cams for cheap so my plan is to try both and see if I can't get that to work and if not to switch over to just the intake.

My clutch basket was also done so I'm going with a GYTR clutch setup, should be nice :busted:

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Have you gone to the YZ header/exhaust? That's a good low end booster. Still selling the IMS Tank listed in your sig? What color and $?

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Like you I have an 07 that's in need of a piston replacement so I figured I would try a couple mods. I got a 13.5-1 HC piston and a set of YZ cams. I plan on doing the rebuild here in a couple weeks.

From what I've found researching the e-start should work with the piston and intake cam and might work with the piston and both cams.

I purchased some slightly used YZ cams for cheap so my plan is to try both and see if I can't get that to work and if not to switch over to just the intake.

My clutch basket was also done so I'm going with a GYTR clutch setup, should be nice :busted:

do you plan on taking the motor out to work on it or not while u do these mods???after doing my valves i might almost think that would be much easier and faster in the long run.....and are you going to re nikasil your cylinder???

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do you plan on taking the motor out to work on it or not while u do these mods???after doing my valves i might almost think that would be much easier and faster in the long run.....and are you going to re nikasil your cylinder???

I'm still on the fence about pulling the motor, but your right in the long run it might be faster. It also gives me a chance to clean and inspect the frame and nooks and crannies.

I plan on just honing my cylinder to bring back the cross hatching. But I haven't seen it yet so I guess I will cross that bridge when I get there.

Has anyone with an 07+ done a piston change ? What's the clearance like removing the cylinder head ?

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I'm still on the fence about pulling the motor, but your right in the long run it might be faster. It also gives me a chance to clean and inspect the frame and nooks and crannies.

I plan on just honing my cylinder to bring back the cross hatching. But I haven't seen it yet so I guess I will cross that bridge when I get there.

Has anyone with an 07+ done a piston change ? What's the clearance like removing the cylinder head ?

ill probably be keeping in touch with you about this because i got the same year bike and plan on doing this to my bike just a matter of when:bonk:

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I'm still on the fence about pulling the motor, but your right in the long run it might be faster. It also gives me a chance to clean and inspect the frame and nooks and crannies.

I plan on just honing my cylinder to bring back the cross hatching. But I haven't seen it yet so I guess I will cross that bridge when I get there.

Has anyone with an 07+ done a piston change ? What's the clearance like removing the cylinder head ?

Just as a fyi, don't make the same mistake I did...

My cylinder was still in spec, my rings were shot, cylinder was smooth, no cross hatch left, and i figured i could get away with just a hone....with new rings

i was wrong...if you have little to no cross hatch left when you get in there,...replace or recoat the cylinder......regardless if it is "in spec" or not

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Thanks guys, good stuff. I guess that I would probably just pull my motor. I think that would be way easier in the long run, and it would be nice to do some thorough cleaning in some areas that are hard to reach. I hadn't thought about getting the cylinder replated at all. I wonder what the cost differences would be between getting: cylinder replated, new piston, and new, OR, getting an athena big bore kit? I'm kind of against the whole big bore idea in general because it just seems like kind of dumb ape way to make power. It's very quad tard-esque type thinking, but you do get a new cylinder and piston, and there is no waiting around for parts to come back. Hmmmmm.

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You may not need to wait for parts to come back if you do have to replate the cylinder.

I'm in Canada, and there is a big replating shop in Quebec. They keep YZ/WR cylinders in stock. Early this spring when I do mine, they will simply ship me one of theirs, I put my old one in the same box and ship it back to them, and get credited the core charge...

I know there are threads/posts on here ... do a search on "Nicasil" (sp?) or cylinder replacement or such and you will find them with links to shops that do it.

I'm sure there are guys closer to your area that can chime in as well.

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Millennium Technologies keeps many of the popular cylinders on the shelf ready to swap with your core as well. Just call ahead of time, they will tell you whether or not they can ship one to you fast.

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You may not need to wait for parts to come back if you do have to replate the cylinder.

I'm in Canada, and there is a big replating shop in Quebec. They keep YZ/WR cylinders in stock. Early this spring when I do mine, they will simply ship me one of theirs, I put my old one in the same box and ship it back to them, and get credited the core charge...

I know there are threads/posts on here ... do a search on "Nicasil" (sp?) or cylinder replacement or such and you will find them with links to shops that do it.

I'm sure there are guys closer to your area that can chime in as well.

Mongoose in Vancouver is only a couple of hours away if I need to replate so that's not an issue.

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My cylinder was still in spec, my rings were shot, cylinder was smooth, no cross hatch left, and i figured i could get away with just a hone....with new rings

i was wrong...if you have little to no cross hatch left when you get in there,...replace or recoat the cylinder......regardless if it is "in spec" or not

What issues did you have because you ONLY honed?

All you say is to replate but you do not give a reason as to why...

The Nikasil plating on the bore is very hard, unless there are deep gashes, there is no reason a quick hone wont work just fine. Might want to see what Gray has to say on the matter...:busted:

http://www.thumpertalk.com/forum/showpost.php?p=6987708&postcount=4

http://www.thumpertalk.com/forum/showpost.php?p=4380759&postcount=4

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What issues did you have because you ONLY honed?

The Nikasil plating on the bore is very hard, unless there are deep gashes, there is no reason a quick hone wont work just fine. Might want to see what Gray has to say on the matter...:busted:

That's what I did with my '03 and put another 6000+ miles on it. Nothing wrong with a light hone. Just finally replaced the cylinder at about 14,000 when I was in the motor doing the valves. It finally developed a ridge at the base of the stroke where the piston changes direction but the nikasil was still in good condition. It was still running fine and not using any oil but since I was in there it was time.

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That's what I did with my '03 and put another 6000+ miles on it. Nothing wrong with a light hone. Just finally replaced the cylinder at about 14,000 when I was in the motor doing the valves. It finally developed a ridge at the base of the stroke where the piston changes direction but the nikasil was still in good condition. It was still running fine and not using any oil but since I was in there it was time.

What is $RP on an OEM cylinder?

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What issues did you have because you ONLY honed?

All you say is to replate but you do not give a reason as to why...

The Nikasil plating on the bore is very hard, unless there are deep gashes, there is no reason a quick hone wont work just fine. Might want to see what Gray has to say on the matter...:busted:

http://www.thumpertalk.com/forum/showpost.php?p=6987708&postcount=4

http://www.thumpertalk.com/forum/showpost.php?p=4380759&postcount=4

Here is the thread on my whole saga.....no gashes, but no trace of the cross hatch left either....

http://www.thumpertalk.com/forum/showthread.php?t=804479&highlight=

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Here is the thread on my whole saga.....no gashes, but no trace of the cross hatch left either....

http://www.thumpertalk.com/forum/showthread.php?t=804479&highlight=

Well that's a little different scenario. You had a problem before you took the bike down. Obviously something was wrong with the cylinder. Since you say it measured ok I don't what would be the problem but I suspect it was out of round somewhere in the bore. In your thread you mention some kind of oiling issue. That's not normal is most likely the underlying cause of your problem. In my case I had a good running engine and elected to replace piston and rings as preventative maintenance. Did a light hone and had no issues.

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Well that's a little different scenario. You had a problem before you took the bike down. Obviously something was wrong with the cylinder. Since you say it measured ok I don't what would be the problem but I suspect it was out of round somewhere in the bore. In your thread you mention some kind of oiling issue. That's not normal is most likely the underlying cause of your problem. In my case I had a good running engine and elected to replace piston and rings as preventative maintenance. Did a light hone and had no issues.

No oiling issue that I can find. I suspected / wondered if I had one though as a explanation as to why I only got 2,000 km's out of a fresh top end. Cylinder was not out of round, and still in min. spec for bore, but not by much (I don't remember the exact #'s now...).

Anyway, I'm still running it, it still hauls ass, and it's slowly smoking a bit worse at high rpm, and oil consumption varies a lot depending on how your riding it...baby it, and just a leisurely putt, and it does not burn any....hammer on the thing, and heavy on the right wrist....it burns oil....I can only come up with blow by...but I'll have a leak down test done before I put it away for the winter.

Over the winter, it's getting new piston, rings, and cylinder (along with gaskets, seals, ect..). I'm going with the therory, that regardless of the cyliner being still in spec (again, not by much though), if it's worn enough that you can not see any trace of the factory cross hatch on the cylinder,and it's getting shiny, it's worn too much..

In all of my searches on here, and i have done a ton on this subject, I have never heard tell of a cylinder being reused after a hone when you could not see a trace of cross hatch left.

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I guess I misunderstood your post. Hard to believe the cylinder would still be in spec if all the cross hatching was worn away. As was mentioned earlier that nikasil is some hard stuff. Are you sure your guide seals are good? Maybe you've got a head problem. Ever done a leakdown test on it?

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