Just changed the 2 stroke oil on him fired him up and noticed bubbles coming out on carb side of head gasket. Was replaced and torqued to Haynes manual specs not 50 miles ago. Can head warp on such a small engine?

Regards Simon

Definitely, the Dt175 has a big bore for the metal in it, the head is relatively soft too.

Its easy to take off though, bit of 500grade wet and dry on some flat surface. Rub in a circular motion and it will flatten out. The head gasket should stand re use.

Be sure to check all the head studs are secure, they have a nasty habit of pulling out of the barrel.

yep the tired old threads just pull out of the barrel, may need a helicoil if you cant achieve a torque spec on one of the studs

Cheers will try the wet and dry on the head. Still runs ok funnily enougH!

S.

it will but if left you may hole the piston.

On the yambits gasket there is a ridge around it. Is it fitted with the raised part of the ridge to head or barrel?

Don't know about 2T but on my twins, if I replace the head gasket, and on auld Triumphs it's almost an annual job, it is recommended re torquing the head after 50 miles and again after 500miles...Possibly not the same on strokers but just saying

Doesent really matter tbh.

Just check the studs are clean and the head is flat and true. Then tighten them down evenly to the right torque.

That is more important really.

Finally removed exhaust. Turns out the rear head stud nut is 12mm socket where the rest of them are 13mm for some reason from the schoolboy 80s. All other head nuts are still torqued. Thread is stripped on stud. Another gasket kit then!

Oh just found the conrod big end is flapping up and down on the crank. and the threads have gone on the exhaust bolts. Woe is me

Up and down simon ? not side to side , my kwaker triple did this on middle cylinder , rattled like hell, well its a crank big end for you then,

Grampian eng [ Liverpool ] will supply and fit .

It did sound like someone hitting the cooling fins with a hammer when it was running. Its got side to side play as well. I see grampian do conrod kits for most machines. Will call them later.

Many thanks!

Looks like my crank is wet with gearbox oil. Smells burnt.

http://i235.photobucket.com/albums/ee14/Simon46/Mobile Uploads/DSC_0243.jpg

And this is my new piston

http://i235.photobucket.com/albums/ee14/Simon46/Mobile Uploads/DSC_0244.jpg

Make sure you fit new seals . 

Again yes. Not even 50 miles since new seals and crank bearings fitted . Seen a post about an o ring so will be checking that too. 

Many thanks Simon 

That o ring fits on the crank under the distance piece behind the primary gear. Easy to miss/forget and easy to break.

Will likely smoke like the qe2 if you left it out.

Edited August 25, 20159 yr by Cynic

Well just been to grampian. Fantastic service. Supplied me with full gasket set double sided oil seal for primary side and single sided for flywheel side. They checked crank o ring and said it was fine. The new rod has a slit in it for oiling the big end more. Nice and tight now!

Regards Simon 

Oops busted by missus who came home early. House stinks of gearbox oil with crankcase in oven at 140 degrees. Frozen Crankshaft just fell into mains. Might be a takeaway tonight!

Oops busted by missus who came home early. House stinks of gearbox oil with crankcase in oven at 140 degrees. Frozen Crankshaft just fell into mains. Might be a takeaway tonight!

did you clean the cases in the dishwasher.?..Top Tip

Already been in trouble for that too. And im a domestic appliance engineer!