bore kit help needed

[kuhnie80]

i bought a 99 400 ex in may and a couple weeks ago i blew the head gasket so i bought a whole gasket set and when i got the head off i noticed that the 3 of the headstuds were helicoiled. but instead of drilled and threaded they were j-b welded in. so basically the jug is trash. it already had a 86mm kit in it. i was wondering what would be the best and cheapest option for me. buying a new or used jug in good condition and doing a 416 or 426 bore kit. or just getting the 440 with the new jug in the kit. also the only valve cover bolt holding on was the center 12 mm the rest were just kinda chillin in there respective spots, can they be drilled and tapped for a larger bolt or helicoiled or should i just invest in a new head? all thoughts and answers are greatly appreciated. thanks

[rocky_mtn_honda]

i'd go with the kit that came with the jug and all...sounds like that thing was beat to hell and back...sheesh

[kuhnie80]

yea to say beat to hell and back is a slight understatment i had to put a rear carrier in to the chain side bearing was completely none existant. the frame and everything looks to be pretty good no kinks or signs of repair. thanks for the input.

[IcutMetl]

My opinion is this. Regardless of what bore kit you decide on, completely disassemble cylinder and head if not already done. Trash any scrap parts and price replacements. Start searching on here & ebay for jugs and heads...price 'em out. Also consider a cam, valves/springs, and cam chain. If you can find a decent job-shop machine shop around you, they'll be more than capable of properly repairing those threaded holes. Consider larger heavy-duty head studs; that might not be a bad alternative to totally replacing your cylinder, and if you salvage your cylinder, a new sleeve should be pretty cheap.

[rocky_mtn_honda]

good point...i guess i just have a problem with forking over my money to another guy to do machine/repair work that i'm not capable of doing! =) hard headed like that...rather spend the extra cash and just have a new one...but thats me for ya

[kuhnie80]

sounds good ive priced the bore kits and such haven't done much on the head though i have an uncle that can machined new threads in the head but said he doesn't have the equipment to do boring or anything that complicated. ive pretty much decided to scrap the old jug and do plan on the hd studs the head has been port and polished and appears to actually have been done pretty well not sure on the springs and valves i do know they seat damn near perfectly though. i have a stage 2 hot cam that i was going to put in until i found all this out. i do mostly trail and field riding but do have some possible tracks id like to try out.

[IcutMetl]

Good luck with it; the 400ex is an awesome 'wheeler...keep it alive!

[kuhnie80]

thanks man apreciate the help

[dariusld]

I would do a new cylinder and get a 11 to 1 stock bore piston. You don't have to bore the new cylinder and still have some bores for later.

[F-16Guy]

You already have a serviceable 86mm piston, right? Don't throw $100 in the trash, buy a set of rings for it. Buy a used stock bore cylinder. Send the piston and cylinder to GT Thunder and have them install studs for you and bore the cylinder to match your piston. In fact, GT Thunder almost certainly has rings and a gasket set in stock, so just have them put everything in the box when they ship your other stuff back. I bought a head gasket from them, and their prices are pretty much on line with everyone else. Do that, and you'll have a bullet-proof cylinder that's ready to install as soon as you get it from them. It will be done right, and you'll get years of service out of it without having to worry about blowing another head gasket. If you buy a kit with a cylinder, does it have HD studs? Probably not. You'll be back to square one in no time. Do it right.

[kuhnie80]

f-16 any ideas on the prices from gt thunder on the boring and studs and what not. and what is general turn around time. i was planning on doing the hd studs regardless of what i decide based on the way the old jug looks. thanks for the help much appreciated

[TRXRacer1]

Take it to a good machinists and have them install inserts for the stock studs. Real easy for a properly tooled shop. Or sell it to me real cheap and I'll do it for one of my projects. PM me if interested.

[kuhnie80]

it already has inserts, they are j-b welded in and are beyond repair. the front, right and rear studs were attempted at being fixed and done completly wrong leaving me to either buy a used stock jug or one that comes with a 440 kit.

[TRXRacer1]

Originally posted by kuhnie80
it already has inserts, they are j-b welded in and are beyond repair. the front, right and rear studs were attempted at being fixed and done completly wrong leaving me to either buy a used stock jug or one that comes with a 440 kit. You said heli-coils, inserts are a whole different thing. If you're going to toss it, toss it my way. I can fix it.

[kuhnie80]

yea if you want ill sell it cheap might be a couple weeks or more till i get the things i need to fix it and what not

[ngates788]

Originally posted by IcutMetl
My opinion is this. Regardless of what bore kit you decide on, completely disassemble cylinder and head if not already done. Trash any scrap parts and price replacements. Start searching on here & ebay for jugs and heads...price 'em out. Also consider a cam, valves/springs, and cam chain. If you can find a decent job-shop machine shop around you, they'll be more than capable of properly repairing those threaded holes. Consider larger heavy-duty head studs; that might not be a bad alternative to totally replacing your cylinder, and if you salvage your cylinder, a new sleeve should be pretty cheap.

i just seen u were from sand town .. im from norwalk lol

[F-16Guy]

Originally posted by kuhnie80
f-16 any ideas on the prices from gt thunder on the boring and studs and what not. and what is general turn around time. i was planning on doing the hd studs regardless of what i decide based on the way the old jug looks. thanks for the help much appreciated

Studs are about $115 installed, cylinder bore and hone is $75, and I think the gasket set was about $40. You'd have to call about rings, but I think they're in the $20-30 range. Turn-around was fast for me, but I'm sure it depends on the time of year and how buys they are. Probably about a week.

Studs:
http://www.gtthunder.com/TRX400EX.htm
Bore:
http://www.gtthunder.com/ServiceRates.htm