DT 125 RE Supermoto Build
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@glynn123 I've never been able to get those cheap gaskets to work. Seriously what's the point!
@calum Yeah mate I know what you mean!
When I built the engine up I was in abit of a budget after getting a new (used) barrel, getting it bored and buying a wossner piston and so on (was at collage and worked part time at mcdonalds haha). I wasnt really aware of the headgasket problems and bought the cheap ebay gasket kit which came with one, something like £10 for the full engine gasket kit haha. I installed all with gasket sealant and wellseal on the head, to be fair the head gasket lasted a good few miles, but got considerably worse after the first time the engine got above 100 degrees. Ended up pressuring the coolant when ran on longer runs and stopping circulation until my temperature gauge on the radiator read over 100 degrees from the steam!!
Ill give wossner and yamaha their due, the piston and barrel were still immaculate, no scores and could see the honing marks like the day I got it bored after 4 boil overs and 600 odd miles. Rings werent even worn!
Head was warped slightly by the boils so skimmed with oil stone, 2000 grit sandpaper and a polishing compound before assembling with athena gasket and a fine coating of wellseal on each surface, I dont believe in installing gaskets without sealant. Been spot on since and hasnt lost any coolant so hoping it stays that way haha! -
@calum Yeah mate I know what you mean!
When I built the engine up I was in abit of a budget after getting a new (used) barrel, getting it bored and buying a wossner piston and so on (was at collage and worked part time at mcdonalds haha). I wasnt really aware of the headgasket problems and bought the cheap ebay gasket kit which came with one, something like £10 for the full engine gasket kit haha. I installed all with gasket sealant and wellseal on the head, to be fair the head gasket lasted a good few miles, but got considerably worse after the first time the engine got above 100 degrees. Ended up pressuring the coolant when ran on longer runs and stopping circulation until my temperature gauge on the radiator read over 100 degrees from the steam!!
Ill give wossner and yamaha their due, the piston and barrel were still immaculate, no scores and could see the honing marks like the day I got it bored after 4 boil overs and 600 odd miles. Rings werent even worn!
Head was warped slightly by the boils so skimmed with oil stone, 2000 grit sandpaper and a polishing compound before assembling with athena gasket and a fine coating of wellseal on each surface, I dont believe in installing gaskets without sealant. Been spot on since and hasnt lost any coolant so hoping it stays that way haha! -
@calum Yeah mate I know what you mean!
When I built the engine up I was in abit of a budget after getting a new (used) barrel, getting it bored and buying a wossner piston and so on (was at collage and worked part time at mcdonalds haha). I wasnt really aware of the headgasket problems and bought the cheap ebay gasket kit which came with one, something like £10 for the full engine gasket kit haha. I installed all with gasket sealant and wellseal on the head, to be fair the head gasket lasted a good few miles, but got considerably worse after the first time the engine got above 100 degrees. Ended up pressuring the coolant when ran on longer runs and stopping circulation until my temperature gauge on the radiator read over 100 degrees from the steam!!
Ill give wossner and yamaha their due, the piston and barrel were still immaculate, no scores and could see the honing marks like the day I got it bored after 4 boil overs and 600 odd miles. Rings werent even worn!
Head was warped slightly by the boils so skimmed with oil stone, 2000 grit sandpaper and a polishing compound before assembling with athena gasket and a fine coating of wellseal on each surface, I dont believe in installing gaskets without sealant. Been spot on since and hasnt lost any coolant so hoping it stays that way haha! -
@declan I used wellseal on my headgasket mate, developed by rolls Royce and used in a lot of racing engines without any gasket at all, just sealant on either surface. Top stuff and never had any trouble with it, doesn't really dry just fills minor scratches in surfaces etc
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If you get head machined flat you can get away with using a single O ring, any machine shop will cut an O ring groove cheap and use a yz O ring.
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If you get head machined flat you can get away with using a single O ring, any machine shop will cut an O ring groove cheap and use a yz O ring.
@2stroketerry I considered doing this, however had a charity ride 2 days after my headgasket went so needed it running again for the weekend so just ordered an athena. My trials bikes always had O rings and never had a problem, if the athena gasket goes I will definetely go down the O ring route.
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Thought it might be about time to update the post, had a brilliant summer with my dt and happy to say it's performed perfectly all year, a few minor problems but nothing major. Been quite a few little mods done since I last updated this thread, I couldn't really remember to list them but you can see for yourself haha
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It's winter again, which means my DT is spread across the workshop.
Going for some more power for next season, plans are 32mm carb, some porting work, fresh piston and zeeltronic cdi
My box of goodies arrived today meaning I can start work
32mm Polini reworked PWK carburetor and some Jets to play with
I'm really happy with how this carburetor is built, one of the best I have seen in person and I've tried new Mikunis etc
Even managed to fit the carb in the standard DT rubber without any modification! Although it was very tight.
While I had the carb off I decided it was time to fit the carbon fiber reeds I've had laying around for over a year, doubt they make much of a difference but wont do any harm
I got the carb in and the bike runs happily on choke, although it does sound lean to me, which I expected. It won't run at all off choke but will be swapping out the pilot jet after work tomorrow for more experimentation -
It's winter again, which means my DT is spread across the workshop.
Going for some more power for next season, plans are 32mm carb, some porting work, fresh piston and zeeltronic cdi
My box of goodies arrived today meaning I can start work
32mm Polini reworked PWK carburetor and some Jets to play with
I'm really happy with how this carburetor is built, one of the best I have seen in person and I've tried new Mikunis etc
Even managed to fit the carb in the standard DT rubber without any modification! Although it was very tight.
While I had the carb off I decided it was time to fit the carbon fiber reeds I've had laying around for over a year, doubt they make much of a difference but wont do any harm
I got the carb in and the bike runs happily on choke, although it does sound lean to me, which I expected. It won't run at all off choke but will be swapping out the pilot jet after work tomorrow for more experimentation -
This is gold let us know how you get on I'm doing the exactly the same thing over the coming weeks so this may be verry helpfull
@stinkwheeler will do mate, sadly doesn't seem as if anyone has tried this carburetor, or at least nobody has wrote about the process online. Shame really as there is a lot of great budget options with the PWK carburetor. I was recommended to use them by 2Stroke stuffing and BARacing. Only problem I'm finding so far is the standard airbox boot is too small for the carb, so I'm looking at buying some hose and making something up so that I can still use the standard airbox.
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@Glynn123 Polini carb looks mint bud, the workmanship is much better than Dellorto's. How much did it set you back???
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@NINJA it was on sale for about £110 on Racing Planet mate, and I think about £20 worth of Jets ontop of that, bargain I'd say
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@stinkwheeler will do mate, sadly doesn't seem as if anyone has tried this carburetor, or at least nobody has wrote about the process online. Shame really as there is a lot of great budget options with the PWK carburetor. I was recommended to use them by 2Stroke stuffing and BARacing. Only problem I'm finding so far is the standard airbox boot is too small for the carb, so I'm looking at buying some hose and making something up so that I can still use the standard airbox.
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@Glynn123 Heat gun and some leverage mate. We fitted a Kehin 38mm inlet manifold to the Stock DTR Air box way back when. So it's definitely doable.
