Control speed on L100 Yanmar.

[bigpaws]

Hello,

I've just joined this forum, and just started my diesel conversion. My Lifan LF 250 (Yamaha Virago XV250 Counterfeit) coughed up an engine, so I decided to convert it.

I got a used Yanmar L100 10HP engine for $450, because the fool who had it used petrol and seized up the fuel injection pump. $85 for a new pump, repairs to a small oil leak, and the engine is running great on the bench. It has good compression, and smokes very little. It makes a Harley-like thump while running. It sounds very nice. All electrical items check out ok, and battery voltage was 12.6V at slow idle.

What I'm concerned about on this project (at this stage...haven't started to worry about transmission or drive yet) is the following:

* Suitable way to control engine speed. Yanmar is set up to be fixed speed with spring setting on governor. I suppose I can remove the entire governor, and wire the old throttle cable to the fuel injection pump.

* How to set up something to kill fuel to the engine with the kill switch from the motorcycle. If this engine ever tries to run away, I want a quick way to shut it down safely. I'm thinking of a solenoid valve fitted before the fuel injection pump.

Any ideas would be appreciated. I'm looking forward to my Lifan getting 100 MPG and hopefully going 100 km/h or better. Previously it got 70 MPG at 120 km/h top speed.

-Bigpaws in Arizona, USA.

[pietenpol2002]

Welcome to the forum Bigpaws, and great to hear of you project. You'lll find plenty of company here with such a project, including others who can help you with the governor dilemma (But that won't be me. Not to that point yet in my build). However, for the record Yanmar does offer an electric solenoid fuel shut-off for the electric start L-series if you're wanting to go with original equipment. Likely won't be cheap.

Good luck with the project and keep us posted with pics etc.

Regards,
Ron

[Fiddler]

Bigpaws,

Its pretty simple to make a variable speed controller. Mines a very simple lever really.
My throttle twistgrip pulls the throttle cable 35mm from idle to max revs but the govenor arm moves only 12mm from idle to max revs. So by attaching a cable to each onto a lever the correct distance from the pivot to obtain the right movement you have it sorted.
The lever is spring loaded and rests in the idle position. It is pulled back to stop the engine by another cable routed to the handlebars.
Check out the Enfield/Yanmar Clone Throttle Setup thread here in the technical talk section. It has some pictures of somebody elses rather smart machined solution. All just variations on a theme really.

Mark

[bigpaws]

Thanks, Mark. I will be fitting the engine into the chassis this weekend, and hopefully will get this sorted out. I'll be sure to post pictures.

[johnfireball]

Hiya Bigpaws,
I think that running without a governor is not possible and connecting throttle direct to pump is a nono.The governor determines the exact fuel amount required for the engine rpm and this you will be unable to do with a twistgrip. This link explains it better than I can.

http://www.altmann.haan.de/riding_on_salad_oil/

Regards John Good luck with project

[sbrumby]

great link a must for anybody building

[bigpaws]

Well, I took the engine off the bench I had it bolted to for testing, and placed it on a cart to see how it would match up with the motorcycle chassis. The results were that I need to find a different bike for this conversion. I'm about 1.5" too high to properly fit in this frame. So, for those who want to use a Yanmar L100 on a Yamaha XV250 or Lifan LF250, it will take modifying the frame (not something I'm willing to do).

I still haven't decided if I'm going to scrap this project for the moment, as the Yanmar is broken in on the bench and runs like a clock. Maybe I'll find another donor bike, maybe I'll have an engine for emergency power generation.