2001? Yzf 426 stroked complete resto

Hi all, New member here. Completly restoring a yzf426 I bought a few months ago. Let me know what you think. Work done so far : powder coated frame, New wheel bearings all around, new swing arm bearings/mono shock linkage rebuild kit(bought but yet to install), new tag triple clamps, new handlebars, new grips, new oversize radiators/blue hosing,new seat cover, new chain guide, all new skidplates(yet to install) jetting kit(yet to instal),new hot start lever, new air filter,all new plastics and decal kit, sandblasted subframe, motor stroked by gt thunder. New cylinder, new high compression piston, hot arms with auto decomp. There's more but I'm tired of typing, here's some pics from last month will post current ones soon. Let me know what you think!

Here's a pic.image.jpg

Bike looks good bud!!! I just got myself a yz426 today!! So far I'm loving it!! Make sure you post pics of engine rebuild. I'm audio is to see inside the engine.

Motors bottom end was done some time ago by gt thunder. Dirt bike shop (Phils Mobile) I bought it off of had it done so I'll only be able to post pics of the top end. Does anyone know how the coil mounts above the engine?

White frame, eh?

Yup the guys at the powder coating shop call it epoxy white. I think it looks cool.

Could use some information. The crank on my engine was redone by gt thunder roughly five years ago. Bike was never finished or run. local shop picked it up bought lots of parts but never did any work on it other then the cylinder,piston,hot cams and some head work. Now they are telling me the stock timing chain is too short. Part of the deal with me buying the bike is that the engine has to be complete,ready to run and warrantied for two years.is it possible to add a couple of links to the timing chain to make it fit? That's what the shop wants to do.thanks guys.

Forgot to mention it's a stroker.

Nice build up, most reliable high strung four stroke out there ! Did you consider doing the 450 body conversion ?

The 450 conversion is what made me decide to keep the bike and invest a little more into it. I've had it like 14 years already, not like I'm losing with it.. Being a machinist mine is going to loose some serious tonnage. The 400 / 426 were overbuilt in a lot of places. The original airbox is crazy heavy compared top to the 450 airbox / subframe unit.

Where does the mechanic propose to get the extra link(s) from, and the pins?

The mechanic figures he can take links off of one new timing chain and add it to another new timing chain.

Doesn't answer the question of how he plans to close the chain back together.  Would he run it in his? 


How much was it stroked?

I will call him tomorrow to find out exactly how much the engine has been stroked. He told me before it stroked to be 450cc but the googling I have done has pretty much turned up 444cc kits so I'm skeptical. Will reply asap with what I find out. Thank you for your help grayracer.

Most common stroker cranks are at about the 3mm figure, which would take a stock-bored 426 out to 447.  The 444 kits are big bore kits adding 3mm to the bore size. 


Ordinarily, the 3mm stroke increase needs only a 1.5mm spacer plate under the cylinder, and that normally allows the use of the original cam chain.  Is the shop familiar with the fact that the chain cannot be assembled onto the cams while they are in place in the head, even on stock engines?

Hey guys, sorry it's been so long since my last post. The mechanic at phils mobile was out of town and is due back tomorrow. I'm hoping to get the measurement of total stroke then. In the meantime my new pro taper bars, clutch perch/lever,spark plug boot and new chain tension bolts/nuts came In. The project slowly Marches on . . . .



Engine is installed as of today! Things seem to be moving along at a steady pace. Next up is the swing arm. . .


Hey Nick, here are the tank pics ! Back in black.

Yamaha 001.jpg

Yamaha 002.jpg

Yamaha 003.jpg

Hey guys. Changed the swing arm bushings/ seals last night at work with the press. The kit came with two metal spacers that fit inside the seals and two rubber spacers that fit inside the seals.Anyone know which ones go where?

Hi guys.Finished rebuilding the mono shock linkage and shock bushings/bearings tonight.Cleaned all parts and filled swing arm with oil as one chain tensioner bolt is broken off.Ive left it to sit overnight. I also replaced the O rings on the coolant line into the cylinder head and the O rings on the oil return line to stop the respective fluids from leaking out onto the ground instead of staying in the engine where they belong. New kickstart lever is installed as well. I downloaded a manual but it is very vague on the swing arm parts so if anyone has the info on the parts I was asking about it would be much appreciated. Assuming we figure this out I will be installing the rear suspension tomorrow and mounting a chain for the first time. . The ImageUploadedByThumper Talk1430901597.326879.jpg

ImageUploadedByThumper Talk1430901621.807007.jpg

Just rode it for the first time! Rips! Next up is putting on the new gas tank and swing arm logos.

ImageUploadedByThumper Talk1431059375.749806.jpg

Your chain looks a little tight

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now