Weak doodlebug frame

ryan275

ryan275

Member
#1
#1
I have searched for 2 hours now and can't find a thing on if anyone has had issues with the mounting plate on the new doodle bugs being weak.

I am running a ctmjay(I butchered it :doah:) mounting plate. And the motor rocks back and forth. I have really tightened it down time and time again. but still it rocks.

I have replaced the flywheel, and I have tried re-aligning it and still it shakes. I just ordered a max torque ss clutch, and some pre-stretched chain. it should be here soon.

should I just cut the old plate off and fabricate my own? or If it might be something else, let me know. Thanks, Ryan
 
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waynelass

New Member
#3
#3
the heat from the torching of the slots probably warped it or you have a little slag ontop ?best to pull the motor and check it with a straight edge .
 
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tlizard2

Member
#4
#4
I also found my engine rocked around quite a bit with the adaptor plate. What I did was to open up the bolt pattern where the plate mounted to the frame and engine. I then also bought some U channel steel and made 2 pieces that would span the engine mount holes underneath to add support. Hope these pictures help. This mod bolted the motor to the frame much more rigidly then the original adaptor plate. To cut the slots I first found the end point of the slot using the original plate the drilled holes at each end. I then used a dremal tool with a cut off disk to make the slots.
 
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cjtmini

cjtmini

#6
#6
this is the first time I've heard anything about the engine "rocking" while the plate is torqued down. your frame engine mount plate must be warped/bent from the :chinese: factory??
 
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tlizard2

Member
#7
#7
cjtmini,

No disrespect to your kit. I just found the engine would rock back and forth on my DB under acceleration. You could actually pull the upper and lower run of chain together and you could see the engine move. That is why I did what I did above. Also I should be say my engine is not stock.

That being said, your mount plate works well and is an easy install for anyone.
 
ryan275

ryan275

Member
#8
#8
hmmm, sounds like the install(adapter) plate is precision machined to be level. What would be the best way to straighten out the frame engine mount plate?

I really like that "u" shaped metal idea tlizard2 had.
 
vette66_00

vette66_00

Active Member
#10
#10
tlizard2 said:
I also found my engine rocked around quite a bit with the adaptor plate. What I did was to open up the bolt pattern where the plate mounted to the frame and engine. I then also bought some U channel steel and made 2 pieces that would span the engine mount holes underneath to add support. Hope these pictures help. This mod bolted the motor to the frame much more rigidly then the original adaptor plate. To cut the slots I first found the end point of the slot using the original plate the drilled holes at each end. I then used a dremal tool with a cut off disk to make the slots.
Click to expand...
The thing about doing the slot idea is the fact you totally eliminate the "easy of use" of Chris' kit. If you are going to the trouble of slotting and drilling don't use the kit.



ryan275 said:
What would be the best way to straighten out the frame engine mount plate?
Click to expand...
Hammer, heat and a straight edge. Or replace the plate. That's about the only thing you can do it get it straight again.





.
 
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tlizard2

Member
#12
#12
Strigoi said:
how much play do you have in your chain?
Click to expand...
What I meant by that was by squeezing the upper and lower run of chain together causes the sprockets to move towards each other, kind of like what happens when your hard on the throttle. When I would do this you could see the engine rock/twist towards the rear of the bike.

After I modded the plate it would no longer do this. The contact area of the origanal engine is much smaller and less spread out the the clone cause the plate welded to the frame to flex. By widening it out as far as possible and bracing it underneath it makes it much stiffer.

Its true by doing what I did it defeats the whole purpose of the kit, thats is to make it a simple bolt on. However I already had the plate and needed the extra height for the NR racing header to clear so I modded it to work for me. I'm sure it would have been fine without modding it but I am a stickler for details.

Ryan, The plate is not precision machined to be flat. It it a piece of extruded aluminum. On mine it kit plate layed flat on the frame. The movement is from the frame plate flexing.
 
ryan275

ryan275

Member
#13
#13
vette66_00 said:
The thing about doing the slot idea is the fact you totally eliminate the "easy of use" of Chris' kit. If you are going to the trouble of slotting and drilling don't use the kit.
Click to expand...

I was thinking about just adding the steel bars to the bolts on the adapter plate, and keeping the functionality of the plate.

Is the (blacksmith) heating and hammering method the prefferd method?
 
valvefloater62

valvefloater62

New Member
#16
#16
I would say you just got a bad frame it happens haven't had a problem with mine its had a clone in it since new and I just drilled and slotted the stock plate its has never threw the chain yet and its got about 8 races on it and has been around a river track close to home jumpin and whopps what ever I feel like and I wieght 320 lol. I wounld just cut the motor plate out and make a new one out of 3/16 or 1/4 inch plate it won't rock then good luck.
 
ryan275

ryan275

Member
#17
#17
valvefloater62 said:
I would say you just got a bad frame it happens haven't had a problem with mine its had a clone in it since new and I just drilled and slotted the stock plate its has never threw the chain yet and its got about 8 races on it and has been around a river track close to home jumpin and whopps what ever I feel like and I wieght 320 lol. I wounld just cut the motor plate out and make a new one out of 3/16 or 1/4 inch plate it won't rock then good luck.
Click to expand...
That plate idea was what i was thinking about doing.


This leaves the door wide open for some sick mods..... any ideas on what i could do? {plate on the bottom of the rails, i could tilt the engine pos. or neg. caster angles (not to the point of messing with the oil flow).} i am getting excited now :grind: :hack: :weld: :clap:
 
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vette66_00

vette66_00

Active Member
#18
#18
ryan275 said:
That plate idea was what i was thinking about doing.


This leaves the door wide open for some sick mods..... any ideas on what i could do? {plate on the bottom of the rails, i could tilt the engine pos. or neg. caster angles (not to the point of messing with the oil flow).} i am getting excited now :grind: :hack: :weld: :clap:
Click to expand...
Put the kick stand on the correct side. LOL
 
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