Converting to premix GT250

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Indy650
Around the block
Posts: 84
Joined: Tue Jul 03, 2018 4:32 pm
Country: Usa
Suzuki 2-Strokes: '74 GT250

Converting to premix GT250

Post by Indy650 »

Has anyone converted their Suzuki 2 stroke to pre-mix? I know that the oil injection feeds some of the crank bearings and I and many of ppl I know have had Polaris snowmobiles with a similar setup and for watercross we convert them to pre-mix and we leave the oil injection going to the bearings but don't hook up the throttle cable to the pump so that besides premix the pump feeds the bearings a little bit of oil. As a long time mechanic I feel the engine would be fine running pre-mix but I'm curious if anyone has experience with this.

One of the reasons I'm doing this is because I have some 34mm flatslide carbs for the bike and the throttle cable wont open the carbs all the way because the oil pump maxes out first. If anyone has a solution for that I would certainly love to hear about it.

Thank you all in advance.
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ConnerVT
Novice racer
Posts: 963
Joined: Wed Jan 18, 2012 8:01 pm
Country: USA
Suzuki 2-Strokes: T500R (now), T500M (40 yrs ago)
Location: North of Albany, NY

Re: Converting to premix GT250

Post by ConnerVT »

How about something really simple? Extend the control arm of the oil pump.
Indy650
Around the block
Posts: 84
Joined: Tue Jul 03, 2018 4:32 pm
Country: Usa
Suzuki 2-Strokes: '74 GT250

Re: Converting to premix GT250

Post by Indy650 »

that's a great idea and i thought of the exact thing the problem is the oil pump cover won't fit if I extend the lever because as it comes up it will hit the cover... I guess if I want full throttle out of the flatslide carbs I need to make a sacrifice somewhere. I normallyu prefer pre-mix anyway but carrying around 2 stroke oil in a pack and making random mixing calculations at the pump doesn't really excite me much...

Anyway, thank you much for your reply.
dollydog
Yeah Man, the Interstate
Posts: 630
Joined: Fri Aug 11, 2017 7:09 am
Country: england
Suzuki 2-Strokes: several gt250 ramairs

Re: Converting to premix GT250

Post by dollydog »

hi mate, i fitted 28mm flatslides to my gt250 years ago and thinking back i used an rg250 gamma throttle cable, which was what the carbs were off originally. can't remember now what i did about the oil pump cable though, but eventually it worked :D i reckon it was too long, so i snipped it and soldered a new nipple on it. just another idea for you to mull over :D
cheers, dd.
GTS250 road registered. TS250 engine, Ramair frame.
GT250 big bang road registered. Both pistons fire the same time. USD forks.
GT285 road registered. Overbored - 58mm and TS125 +2 pistons fitted.
GT10 road registered. '65 T10 engine, GT250 frame.
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