A forum for owners of Yamaha TTR250 trail and enduro bikes!

JVOHV · Member

TTT250 project

JVOHV · Member

Can't forget to add a pic with the totallyttrs sticker!

mossproof · Super Guru

You've made a nice job of the rebuild, well done.
I use Helicoil to repair stripped threads - you drill out the old thread, tap a new thread in then fit a special hardened thread insert which locks itself into place and brings the hole back to the original size. ABSOLUTELY NO NEED to buy a new engine case.
Another alternative would be to find a larger sump plug and drill and retap the hole to suit. There are alternatives to Helicoil kits too. I seem to recall someone on here recently mentioning another system. I'll have a search...
I bet Brian (TTRFAN) would be interested in your old carb)

Edit: Scroll down a couple of lines in the repairs section to "...use of helicoil...cam cap bolts..." some good pics of the process from ttrfan.

-- Edited by mossproof on Wednesday 25th of October 2017 09:58:31 AM

JVOHV · Member

Mossproof,
Thank you for the tip, your advice made my day. I'm familiar with helicoil, just have never done it and wasnt sure how it would work longevity wise. After seeing the posts, I'm excited... looks like I'll be able to afford a new exhaust and bash gaurd! Thanks again for you help

TTRfan · Super Guru

I Helicoiled a sump plug a few years back but did it with the TTR just leaning over enough to get the drill underneath. I didn't drill and/or tap the thread at 90 degrees and, whilst the Helicoil worked great, I had to use a Dowty washer to get a seal.

So try and get the TTR actually on its side so that you can get that all-important 90 degree angle for the drill and tap wink

Brian

JVOHV · Member

Thank you, Brian! I appreciate the advice. I tend to screw things up when I'm trying to be overly cautious so any tips help

JVOHV · Member

I'm assuming helicoil will crate a fair amount of metal shavings, will a few flushes with cheap oil be enough to clear out any risk for engine damage? The only other option I can think of is to take apart the engine and isolate the left crank case

ttr steve · Super Guru

Good advice from others as usual smile If you get stuck with the crankcases I have some good used ones here https://totallyttrs.com/epages/699105d9-e4cc-4b32-b236-84e72cd67f84.sf/en_GB/?ObjectID=8938100

Way cheaper than buying new.

Steve

mossproof · Super Guru

If you take the right side plate off (clutch cover) there is a hole big enough to see through into the central gallery so you can see any swarf in there. May be able to pick some out with some chewing gum on a stick, then flush the rest out. When you drill, most of the swarf should come out rather than going in, and you can trap a lot on the tap by smearing it with grease.

Dowty washer is a good tip anyway whether your hole is straight or not, as they don't need to be really tight for them to seal, and the rubber makes them fairly secure from rattling loose.

Good luck, hope you're rolling soon,

Simon.

PS Time serts are the other option mentioned in the other thread - seem similar to helicoil. You pays yer money and you takes yer choice!

www.timesert.com/html/mtrcsert.html

TTRfan · Super Guru

mossproof wrote:
snip....
I bet Brian (TTRFAN) would be interested in your old carb)

I certainly would be interested! Please let me know if it's for sale wink

Brian